Your complete pregnancy calendar

1 week

Week 1: Baby—a gleam in your eye

How things develop

Week one is actually the week of your last period before your egg is fertilized (about two weeks later) and you get pregnant.

How you change

During this week, your body starts preparing for conception and pregnancy.

Week 2: Your body’s getting ready for baby

How things develop

Right between weeks two and three (about day 14 of a 28-day cycle) an egg will be released into your fallopian tube (“ovulation”).

How you change

At this point in your cycle, your uterine lining is developing as a result of hormones your body is secreting to make the uterus receptive to the fertilized egg.

Week 3: Congratulations, it’s a zygote!

How baby grows

During the third week, your fertilized egg is a zygote (created when the sperm and egg unite), moving along the fallopian tube towards the womb. The egg begins as a single cell, which divides again and again, then enters into the lining of the womb.

How you change

Right between weeks two and three (about day 14 of a 28-day cycle) an egg will be released into your fallopian tube—this is called "ovulation." Once the egg has been released, it is fertilized, you become pregnant, and the fertilized egg begins its journey to the womb.

Week 4: Blasting into development

How baby grows

By week four, your zygote has continued to divide, becoming a group of cells with an outer shell called a blastocyst. The blastocyst enters the uterus, and splits into two parts that will become the placenta and the embryo.

The placenta carries oxygen and nutrients to your baby and carries waste products away from her. The other half of the egg will develop into the embryo, otherwise known as your baby-to-be.

During this week the following also occur:

  • Spinal cord development. A sheet of cells on the back of the embryo folds in the middle to form a tube that will become the baby's spinal cord.
  • Brain section development. One end of the tube enlarges to form the brain's major sections.

How you change

  • Pregnancy symptoms. Hormones from your ovaries may trigger fatigue, tingling, and aching breasts or nausea.
  • Missed period and possible spotting. By the end of this week you may notice that you've missed your period, although some women do experience spotting. Usually spotting is lighter than your normal period. Be sure to talk to your doctor if you have any concerns at all.

Week 5: Growing strong

How baby grows

Your tiny embryo’s still only a bit bigger than an apple seed, but your baby’s very busy creating the three cell layers that will later form organs and tissues. Here's how each layer will develop:

  • The top layer. By the end of this week, the neural folds in the top layer of cells begin to fuse into a tube running from the top to the bottom of the embryo. The folic acid in your diet will help this take place. The top part of this tube will eventually form the front part of the brain. A bulge in the center of the embryo will become your baby's heart, which will start to beat this week. The rest of the tube will become your baby's spinal cord and backbone.
  • The middle layer. These cells will produce the circulatory system, bones, most muscles, cartilage, sex organs, and kidneys.
  • The bottom layer. These cells will form the lungs, intestines, and the beginnings of the urinary system.

How you change

  • Missed period. You’ll have missed your period or have experienced slight spotting.
  • Pregnancy symptoms. You might get morning sickness (feel nauseated) or feel fatigue. 
  • Unappetizing smells and tastes. Strong smells or tastes may get to you during this time, so it might help to stay away from oily or fried foods and spicy dishes. Even strong-smelling cleaners and disinfectants may bother you right now.

Good to Know

Don't worry if you don't experience these symptoms. You may be one of the lucky moms who sail through early pregnancy without feeling nauseated at all!

Week 6: Eyes, and organs, and limbs, oh my!

How baby grows

Your baby is still only about the size of a kidney bean. But this is a big week, as organs and parts of the body begin to take shape.

Will her eyes be brown, blue, green, or hazel? It's much too early to know, but by week six her eyes are beginning to develop and the earliest version of the retina is forming.

It’s not just the eyes that are developing now:

  • Neural tube. The neural tube, which connects the brain and spinal cord, will close this week. 
  • Heart. Still located on the outside of the body, the heart is dividing into chambers. But it’ll still be many weeks before the heartbeat can be heard with an instrument.
  • Limbs. Upper and lower limb buds are forming on the body and will eventually develop into arms and legs.
  • Brain. The brain begins to fill your baby's skull.
  • Facial features. As nostrils become distinct, facial features are already forming.
  • Organs. The kidneys, liver, pancreas, lungs, stomach and intestines are developing.
  • Placenta. The lining of the placenta develops to provide the oxygen and nutrients your baby needs for its growth.
  • First movements. Halfway through this week your baby will make her first movements, but you'll have to wait until your second trimester before you can actually feel her wiggling around.

How you change

  • Breast changes. Hormonal changes may cause your breasts to become larger and more sensitive. You may even experience tingling sensations and the areola may start to darken.
  • Weight change. You may have gained two or three pounds. But if you've been experiencing morning sickness, you may actually have lost some weight.
  • Morning sickness. If you're experiencing nausea, it may get worse this week as your hormone levels rise. Even though it's called "morning sickness," it's perfectly normal to feel nauseated at any time of the day or night.

Protecting your baby

Starting now, and for the next few months, you'll need to be extra careful about toxins and infections. That's because your baby is especially vulnerable to birth defects in the first three months.
- Don't change your cat's litter. If you have a cat, ask a family member to change the litter to avoid risk of toxoplasmosis, an infection caused by parasites common in cat feces. It can be passed from Mom to baby.
- Check with your doctor. Don’t take any medication— even those that you can buy without a prescription – without talking to your doctor first.
- Don't handle insecticides or other poisonous substances.

Week 7: Hooray, it's a heartbeat!

How baby grows
Right about now the digestive system is beginning to develop, and you two are really getting connected, as the umbilical cord has started taking shape. This rope-like cord will carry oxygen and nutrients to the embryo and carry away waste products.

And baby’s growing quickly, too! In fact, this week the embryo will more than double in size, growing from a bit more than 1/8 of an inch long to about half an inch.

You’ll be able to see her in all her glory on an ultrasound now, and check in on all the new developments your baby’s experiencing:

  • Facial features. Tiny nostrils and a minuscule mouth have started to develop.
  • Ears. Indentations are appearing where ears will be.
  • Eyes. Your little one is developing more distinct eyes, with pigmented irises.
  • Head. Your baby's head is still much larger than the rest of the body, but her body will grow rapidly this week.
  • Heart. A quickly beating heart (about 150 beats per minute) with two chambers is developing.
  • Airways. Bronchial tubes are developing to carry air through the lungs and carbon dioxide out of the lungs.
  • Mouth. Tooth buds and palate are just beginning to grow.
  • Skin. Your baby has paper-thin skin with clearly visible blood vessels.

How you change

  • Weight gain. You’re probably not quite ready for maternity clothes, but you may have gained a few pounds if you haven't been too nauseated to eat. 
  • Morning sickness. During the first trimester, many women get morning sickness, caused in part by pregnancy hormones.
  • More bathroom breaks. As your enlarging uterus presses on the bladder and hormones affect your fluid balance, you'll probably need to use the bathroom more often than before.
  • Increased energy. If you're getting enough rest, you may begin to have more energy now.

Week 8: Go with the (blood) flow

How baby grows
This week, baby will be about half an inch long and is starting to fine-tune her bone, joint, and limb development.

And there are many other changes happening as well:

  • Eyelids. Eyelids are beginning to form.
  • Fingers and toes. Tiny finger and toe buds appear.
  • Nose. The tip of your baby's nose is taking shape.
  • Blood flow. Blood is beginning to flow through a rudimentary circulatory system.
  • Genitals. Gonads are beginning to transform themselves into either testes or ovaries.
  • Ears. Ears are developing both inside and out.
  • Elbows. Elbows have just started to appear.
  • Vertebrae. Vertebrae and ribs are beginning to grow.
  • Muscle. Muscle and two layers of skin are forming.

How you change

  • New emotions. You may experience lots of emotional highs and lows now. Try not to worry about it too much. Mood swings are a common pregnancy symptom, because hormone levels are going dramatically up and down.
  • Breast enlargement and bigger waistline. 
  • Cramping. Even though you may not be showing yet, your uterus has grown from about the size of a lemon to as big as a grapefruit. As your uterus grows, it's totally normal to feel some cramping, discomfort, or tightening.
  • First doctor's visit. This is a good time for your first office visit for urine and blood tests, a general physical examination, baseline blood pressure evaluation, weight check, pelvic exam, Pap smear, and a review of your family health history.

Week 9: Baby starts showing off her muscles

How baby grows
Baby is now about the size of a peapod and weighs a little less than half an ounce.

Your baby's muscles, nerves, and organs are continuing to form. In fact, if you press against the uterine wall when you touch your belly, your baby will move away, but you won't be able to feel her move around for several more weeks.

Genitals are also beginning to develop, but it's still almost impossible to tell on ultrasound whether it’s a boy or a girl.

By week nine your baby's growth includes:

  • Increased body growth. Her head is quite large compared with the rest of her body, and it curves onto her chest. Her arms have grown, her hands are now flexed at the wrists, and her legs are lengthening. Her feet may be long enough to meet in front of the body.
  • Digits. Baby's developing clearly visible fingers and toes.
  • Eyelids. Developing eyelids begin to cover the eyes and fuse together. Her eyes won't open until about week 27.
  • Ears. Development of the inner and external ears is almost complete.
  • Brain. Baby's far from being conscious, but she's experiencing the first nerve connections in her brain.

How you change

  • Increased blood volume. Although you still may not have gained much weight, your blood volume continues to rise. By the end of nine months your body will actually have produced 30 to 35 % more blood.
  • Fatigue. You may continue to feel tired, nauseated, and dizzy, but take heart: This will most likely fade away soon.
  • Testing. If you're over age 35 or have a family history of genetic illness, talk to your doctor about prenatal genetic diagnosis. Chorionic villus sampling (CVS) is usually done between 10 and 12 weeks to screen for birth defects. Amniocentesis is performed about four weeks later. Both tests have risks of miscarriage that should be carefully discussed with your doctor.

Good to know

If you've been identified as being high risk for other disorders, such as Tay-Sachs or cystic fibrosis (based on your family health history), your doctor may want you to be tested for those conditions as well.

Week 10: Wow! Your baby's almost a fetus

How baby grows
It’s official! This week marks your baby's last week as an embryo; as your baby’s brain growth speeds up and neural cells continue to multiply. The rest of her body’s growing too; she's now about the size of a small plum and weighs about half an ounce.
Next week she'll officially become a fetus.

And there's still a lot of other activity keeping baby busy:

  • Teeth. Tooth buds for baby teeth will begin forming inside the mouth.
  • Reproductive organs and external genitals. They will be formed, although it will still be too early to determine gender.
  • Nervous system. This will continue to develop.
  • Internal organs. Many of the internal organs will begin to function.
  • Intestines. They have been developing inside the umbilical cord and have begun moving into the abdominal cavity.
  • Taste buds. They will begin to appear on the surface of the tiny tongue.
  • Upper lip. This will form completely.
  • Joints. Most of the joints will form, including elbows, wrists, knees, shoulders and ankles.

How you change

  • You're still in regular clothes. Despite your baby's growth spurt, you can probably still wear your regular clothes. Very little of your total pregnancy weight gain—usually between 25 and 35 pounds—will happen during the first three months.
  • Fatigue and nausea. You may still feel tired and a little sick, but it may help to know that in a few weeks, you'll probably be feeling a lot better!

Week 11: Baby’s officially a fetus…and has fingernails!

How baby grows
By the end of this week your little fetus will be about two inches from head to bottom and still weigh about half an ounce—but she'll double in size and weight over the next three weeks, and her major organs are now fully developed.

Other changes you can expect this week:

  • Fingernails will begin to appear.
  • Ears. Your baby's ears will move toward their final position on the sides of her head.
  • Genitalia. Your baby's external genitalia are beginning to develop, and in a few weeks an ultrasound exam may tell you whether you're having a boy or girl.
  • Action! Your baby will begin to swallow and kick.
  • Bones. They will begin to slowly solidify, although most of the skeleton is still made of flexible material.
  • Brain. Nerve cells in the brain are busy connecting with each other, building pathways for future communication.
  • Spinal nerves. They will begin to stretch out from the spinal cord.
  • Heartbeat. With a special handheld device, your doctor will be able to hear the fetus' rapid heartbeat.

How you change

  • Uterus expansion. As you get near the end of the first trimester, your uterus continues to expand, almost filling your pelvis as it supports your growing baby. 
  • Waist growth. Your waist keeps growing, but it’s probably not time for maternity clothes yet.
  • Skin changes. Changes in your hormones can lead to an increase in your skin's production of melanin, and a dark vertical line of pigmentation on your abdomen, called the linea nigra, might appear. This line is a common sign of pregnancy and will fade after pregnancy. The fairer-skinned you are, the less noticeable this line will be, during and after pregnancy.
  • Hair and nail changes. Hormones also affect hair and nails. Many women find that their nails grow faster and their hair stops shedding. As a result your hair will seem thicker and fuller than ever before.

Be careful

There’s nothing wrong with looking good, but watch out for hair dyes and perms. Even though there’s no proof that dyes or perming chemicals can harm your growing baby, it's still a good idea to wait until after the birth.

Week 12: That beautiful face!

How baby grows
By now, your baby has a profile, complete with a little chin and a tiny nose. Inside the mouth, folded tissues have join to form the palate, or roof of the mouth, which separates the oral and nasal cavities.

Your baby’s almost doubled in size in the past few weeks, to almost 3 inches long!

Some other fascinating things will happen this week:

  • Kidneys. Amniotic fluid will build up as your baby's kidneys begin to produce and excrete urine into the fluid.
  • Pancreas. It will begin to produce insulin, a hormone that regulates blood sugar levels.
  • Liver. It will start to secrete bile, a thick, greenish fluid stored in the gall bladder that helps the body digest fats.
  • Digestive process. The muscles in the intestinal walls will begin to practice contractions. Basically your baby is practicing the digestive processes that will begin after birth.
  • Brain. The brain's basic structure is intact by the end of this week, and brain mass is growing all the time.
  • Pituitary gland. It will begin to produce hormones.
  • Hair. Soft, non-pigmented hair—believed to protect your baby's skin before birth—will begin to appear on your little one's body. Most of this hair, called lanugo, will disappear soon after birth.

How you change

  • Uterus enlargement. Sometime during this week your uterus will probably move upward and forward as it continues to enlarge. This means less pressure on your bladder for a while. Eventually, however, your uterus will get large enough so that it will push against the bladder again, increasing your need to urinate.
  • Skin radiance. During this week, as more blood flows through your blood vessels and hormones increase oil gland secretion, you may experience flushed, plumper, smoother skin. 
  • Skin problems. Hormone-related oil activity may have other effects on your skin, such as temporary acne or brown patches called chloasma on the face or neck. Not to worry: Most of these skin problems are only temporary, and disappear after birth.
  • Nausea and fatigue goes away. Many women now start to feel better in the pregnancy as fatigue and nausea fade away. 
  • Weight gain. Because of hormonal changes, you may notice that you're gaining weight in your hips, legs and sides.

Week 13: Getting ready to make some noise

How baby grows
Even though it's still pretty early in your pregnancy, your baby can already do a lot. If you poke your stomach gently with your finger, your baby may begin to turn her head toward you. Some experts think this may be the beginning of the rooting reflex (looking for a nipple).

By now your baby can put a thumb into her mouth, although her sucking muscles aren't completely developed.

Girl babies will have already accumulated about 2 million eggs in their ovaries, although this number will drop to 1 million at birth.
Her head growth has slowed down; this week it makes up about half her body length. By week 21 her head will be about a third the size of her body, and by birth it will only be about a fourth.

Now about 3 inches long and weighing little more than an ounce, your baby would fit snugly into your cupped hands, but your baby’s got lots more growing to do before you’ll have a chance to hold her.

Here's what else to look forward to this week:

  • Tiny ribs will develop.
  • Vocal cords will begin to form.
  • Eyelids will fuse together to protect her delicate eyes.
  • Tissues and organs will continue to mature.
  • Bone marrow, liver and spleen will be able to produce blood cells now.
  • Fingerprints begin to form.

How you change

  • Increased comfort. As the second trimester approaches, most women begin to feel much more comfortable than they did in earlier stages of pregnancy. The side effects of early pregnancy (frequent urination, fatigue, nausea, dizziness) generally lessen during the second trimester. 
  • Abdominal achiness. At 13 weeks the uterus starts growing upward into the abdomen, and you may feel some abdominal aches as the ligaments supporting the uterus stretch. 
  • Weight gain. As your baby starts growing rapidly, you'll see your weight increase.
  • Colostrum production. Even though birth is still months away, your breasts may already have started to make colostrum, the nutrient-rich fluid that will feed your baby for the first few days after birth. 
  • Breast changes. As the breasts enlarge, you may notice veins appearing under the skin and the areola enlarging and turning brown. Experts think this darker color around the nipple may be a visual cue for the breastfeeding baby.
  • Stretch marks. You may start to see the first signs of stretch marks on your abdomen, breasts, hips or buttocks. Since stretch marks are partly genetic, you may be able to predict ahead of time whether you'll experience them or not.

Good to know

Lotions may help calm the itchiness that sometimes goes with stretch marks. Lotions may also help reduce the marks, but it’s hard to completely prevent them. The good news is that they’ll be less noticeable after pregnancy, when they'll probably fade to a more normal skin color.

Week 14: Tiny hands

How baby grows
Your baby now weighs between 1 and 2 ounces and is about 3.6 inches long.

This week soft, peach fuzz-like hair begins to appear on her head, although by delivery day its texture and color may change. Lanugo (very fine, downy hair) continues to grow over her body to protect her delicate skin. Fine, soft eyebrows are also appearing.

Here's what else you can expect this week:

  • Breathing motions. You won't be able to feel it, but your baby is practicing breathing motions, moving the amniotic fluid in and out of her lungs.
  • Prostate gland begins to develop in boys.
  • Ovaries descend from the abdomen into the pelvis in girls.
  • Growth hormone production. As the thyroid matures it produces more growth hormones.
  • Ears and eyes. They continue to move into place.
  • Neck elongation. Your baby's neck is getting longer.
  • Hand function. Tiny hands are beginning to function, although their movements may be mostly reflexive.

How you change

  • Skin changes. Skin spots or moles may be getting bigger or darker—or you may see some new moles developing. If an existing mole changes dramatically, make sure to have your doctor check it.
  • Constipation. At this point in your pregnancy, you may experience bouts of constipation as your uterus presses on the bowel and your hormones relax the bowel muscles, making them less efficient. Eating lots of fiber, drinking plenty of liquids, and exercising sensibly can help with constipation. It's always a good idea to check with your doctor if constipation persists.
  • Testing. At this point you should talk with your doctor about the need for a blood test called the triple-screen. This test is used to estimate the risk of having an infant with one of several birth defects, such as brain and spinal cord malformations or Down syndrome.

As always you should discuss any risks involved with these or any other tests with your doctor.

Week 15: The hipbones connect to the…

How baby grows
Your baby bundle is now about the size of a softball, and is developing a complete skeletal system and muscles, too. This week you also can expect the following:

  • Hair color. Your baby's hair will start to take on color as it continues growing.
  • Bone marrow. Marrow develops and is the source of stem cells, which are special blood-forming cells in the body.
  • Ears. They're almost in their final position now, although they're still a bit low on the head.
  • Thumb sucking. Your baby may begin to suck her thumb, so during an ultrasound, watch closely for this!
  • Eyes. They're still wide apart, but as your baby's head takes shape, her eyes will move closer together and into their final position.

How you change

  • Increased blood volume. At this time, your heart pumps about 20 percent more blood than before you were pregnant to supply your baby with more oxygen. 
  • Measurements. This week your doctor may begin to measure your "fundal height"—the distance from the top of the uterus to the pubic bone. By measuring your fundal height, your doctor can determine whether your baby is growing as expected.

Week 16: Hi, smiley!

How baby grows
You're not the only one who's smiling! Your baby can now make facial expressions because of the development of her facial muscles. This week she can squint, smile, and frown.

Other highlights this week include:

  • Growth. Overall growth continues, and your baby now weighs about 2.8 to 3 ounces and is about 4 or 5 inches long.
  • Head control. Her ability to make some voluntary muscle movements means she can now hold her head somewhat erect.
  • Light sensitivity. Your baby is developing sensitivity to light and may respond with heart rate accelerations to projections of light on the abdomen. Later in pregnancy, this can serve as a test of well being before birth.
  • Hiccups. They may start now, but you won't hear or feel them because the baby's system is filled with fluid rather than air.
  • Heart. Her heart is now pumping the equivalent of 25 quarts of blood each day. 
  • Increased coordination. Arm and leg movements are becoming more coordinated.
  • Bladder. Your baby's bladder will empty about every 40 to 45 minutes.

How you change

  • Need for more rest. As your pregnancy progresses it's important to get plenty of rest. 
  • New sleep position. The best position for you now is lying comfortably on your left side, perhaps with a pillow propped against your back and another between your legs. By lying on your left side you'll experience better digestive functioning, improved blood and nutrient flow to the placenta, and less swelling of hands, feet and legs. 
  • By lying on your left side, you’re also reducing pressure on the vena cava, a large vein that transports blood from the lower part of your body to your heart, and this position allows both you and your baby to receive more oxygen. 
  • Avoid lying on your back because your uterus could block important blood vessels in the back of your abdomen and interfere with circulation to you and your baby. Also avoid lying on your stomach, which puts too much pressure on your growing uterus.
  • Aches. If you move suddenly you may feel an ache in your sides. Not to worry. What you're feeling are the ligaments on the sides of your uterus and pelvic walls stretching as your baby grows. It's normal to feel some discomfort, but if it continues for a few days or increases, talk with your doctor.

Week 17: Your baby's 5 inches long!

How baby grows
Your baby is now almost 5 inches long and weighs about 4 to 5 ounces. She's firmly anchored via the umbilical cord to the placenta, which continues to grow with her. The placenta, which is now more than an inch thick, contains thousands of blood vessels that exchange nutrients and oxygen from your body to your baby.

Big happenings this week include:

  • Fat production. Layers of fat are beginning to develop under the skin to help keep your baby warm and protect her after birth.
  • Skeletal changes. A rubbery skeleton continues to develop, although her bones are still mostly cartilage, flexible enough to enable her to pass through the birth canal.
  • Spinal cord protection. A protective coating called myelin is slowly beginning to cover your baby's spinal cord. This coating will help protect the cord for the rest of her life.
  • By week 17 your baby’s digestive system is continuing to develop, and waste is beginning to build up in her bowels.

How you change

  • Weight gain. By now you've probably gained about 10 pounds.
  • Increased secretions. As your blood volume continues to increase, you may notice you're sweating more and may have more mucus and vaginal discharge. The secretion of these substances will drop to normal levels after the birth of the baby.
  • Clumsiness. You may also feel a bit off-balance as your slowly enlarging uterus shifts your center of gravity. This can contribute to the "pregnancy clumsiness" some moms feel. Just take your time, watch where you're walking, and wear comfortable, low-heeled shoes.
  • Increased foot size. Be prepared for your feet to increase in size and/or flatten out a bit from the excess weight.

Week 18: Your baby can hear!

How baby grows
By now the bones of your baby's inner ear and the nerve endings from the brain have developed enough so that your baby can probably detect sounds clearly. Experts believe that one of the most comforting sounds she hears is Mom's heartbeat. She may also hear your voice, your stomach rumbling, and the sound of blood moving through the umbilical cord to and from the placenta, which is now almost as big as she is.

Here's what else is happening to your baby this week:

  • Starts to swallow. Some experts think thirst may trigger your baby to swallow. Since amniotic fluid is constantly being produced, your baby's swallowing of excess fluid helps keeps it at a constant level.
  • Mimics breathing. Your baby's chest will continue to move up and down to mimic breathing, but she's not breathing air—just swallowing and inhaling amniotic fluid. This is a normal part of your baby's development, and won’t harm her.
  • Female reproductive parts. If your baby is a girl, the vagina, uterus, and fallopian tubes will be in place by the end of this week.

How you change

  • Weight gain. On average, pregnant moms have gained about 10 or 11 pounds by now. 
  • Trouble sleeping. If you're having difficulty getting a good night's sleep because of this added weight and the resulting discomfort, try propping yourself up with pillows in bed and resting on your left side.
  • Ultrasound. This week your doctor may prescribe a mid-pregnancy ultrasound, which is often recommended sometime during the second trimester, usually between 18 and 22 weeks. This test can help your doctor assess fetal growth and development, screen for certain birth defects, check the placenta and umbilical cord, and determine whether the projected due date is accurate.

Week 19: Feeling the first flutters

How baby grows

This week your baby will grow to about 5 or 6 inches and will weigh about 7 ounces by week's end.

This week, you may have the thrill of feeling your baby's first movements, called "quickening". If you've already had one child, you'll probably feel those first flutterings about two weeks earlier than you did in your first pregnancy, mainly because you know what sensation to look out for.

Your baby is also working on protecting her skin as she develops a waxy substance called vernix caseosa, which will disappear at birth. Vernix caseosa protects the growing skin from becoming chapped or wrinkled from floating in amniotic fluid.

How you change

  • Dizziness. Recurrent dizziness is common and nothing to worry about. If you feel dizzy when you stand up quickly, this might be caused by gravity rapidly draining blood from the brain. Standing up slowly will help with this problem. 
    • Also, when you're lying down on your back, your uterus may compress important blood vessels, causing lowered blood pressure and increased dizziness. You can help combat this by sleeping on your left side, which can allow better digestive functioning and may help lessen swelling in your arms and legs.
  • Blood sugar fluctuations. Pregnancy also affects your blood sugar level. Eating a balanced diet of small, frequent meals and not skipping meals can help regulate your blood sugar.
  • Childbirth class. If you're a first-time parent or you'd like a refresher course, a structured class can help prepare you for labor and delivery. You'll want to be finished with class no later than 37 weeks, when you'll be considered full-term. Labor could start at any time from then on.

Week 20: Baby’s halfway home, and getting brainier every day

How baby grows
The 20th week is an important time for your baby's sensory development. Taste, smell, hearing, seeing, and touch are now developing. As existing nerve cells get bigger and make more complex connections with each other, the brain's production of additional nerve cells will slow.

Your little one now weighs about 9 to 12 ounces and has grown to about 6 to 8 inches in length. She's come a long way since her first days as a microscopic collection of cells but has a lot more growing to do at birth.

Believe it or not, you're halfway there on the journey toward holding your new baby! Other baby developments this week include:

  • Skin. Under the protective vernix coating, her skin will continue to develop into three layers: the dermis, epidermis and subcutaneous layers.
  • Nails and hair. Your baby's nails and hair will continue to grow.
  • Heart. Your baby's heartbeat will be stronger now, and the heart will beat about twice as fast as yours. You can hear it this week through a stethoscope.
  • Increased size. Your baby will take up more and more space in the uterus, and her continued growth will put more pressure on your lungs, stomach, bladder and kidneys.

How you change

  • Increased uterus growth. Your uterus has reached your navel. If you're much bigger than normal your doctor may perform an ultrasound to see whether you're carrying twins or if your estimated due date is correct.
  • Stretched abdominal muscles. The enlarging uterus will begin to stretch your abdominal muscles, and they may begin to pull apart as your baby grows. 
    • These muscles are attached to the lower part of your ribs and stretch down to the pelvis. You can see the separation more clearly if you lie down and raise your head, tightening the abdominal muscles—you'll notice a bulge in the middle of your abdomen. It isn't harmful or painful. After you give birth these muscles will return to their original place, and the separation will become less noticeable.
  • Skin itchiness. You may also notice your skin is getting itchy as the uterus grows and stretches the skin. Lotions may help soften skin and ease the itch.
  • Belly button changes. Don't be surprised if your belly button has changed from an "innie" to an "outie" and starts to protrude. This change is a result of the pressure behind it. It will revert to close to its pre-pregnancy shape after delivery.
  • Varicose veins. Varicose veins are simply blood vessels that are filled with pooled blood. They usually appear in the legs or vulva. 
  • Wearing support hose, sleeping on your left side, and elevating your legs can help drain the veins. It's also a good idea to stay off your feet, wear flat shoes, and avoid crossing your legs. Varicose veins usually become less noticeable after delivery.
  • Shortness of breath. Some women have a bit of trouble catching their breath as their internal organs press against the lungs. This breathlessness will usually continue until the baby moves into position in the pelvis (“drops”). For first pregnancies, babies usually drop four to six weeks before birth. With subsequent pregnancies it occurs closer to when labor begins.

Week 21: Sleepy time

How baby grows
Beginning this week, your little one's sleep begins to settle into identifiable patterns. You might be able to tell when she’s sleeping if you notice that her movements slow down dramatically.

Some experts believe that your eating and sleeping habits, along with how much light and noise there is in your environment, all combine to help your baby synchronize her internal clock.

Here are some other developmental highlights that occur this week:

  • Brain growth. Her brain will be growing very quickly, especially the structure deep in the center of the brain responsible for producing brain cells. This structure will disappear shortly before birth.
  • Organ maturity. Your baby's general growth pattern will slow down, but different organs will continue to mature, her heart will beat more strongly, and her legs will reach their correct proportions.

How you change

  • Weight gain. The average mom has now gained 10 to 15 pounds. You may put on as much as half a pound to a pound a week from now on.
  • Breathlessness. If you're feeling out of breath around week 21, don't worry that you're out of shape. As your body continues to change to accommodate your baby and your expanding uterus further compresses your lungs, breathlessness can become more pronounced. 
  • Backaches. You may also notice your back aching a bit now, so it's a good idea to be conscious of your posture and take care to lift and carry properly.

Week 22: Baby can feel!

How baby grows
This week nerve endings become functional enough so that your baby can feel! She may experiment with this new sense of touch by stroking her face or feeling other body parts to see how they move. She may stretch her muscles by pushing against the wall of your uterus with her feet or head.

Your baby weighs almost a pound now and is 7 to 8 inches long. Although she's filling out, her body still appears wrinkled because she lacks a significant layer of fat beneath her skin.

In addition, your baby's liver is busy breaking down bilirubin, a substance formed by the breakdown of hemoglobin in blood cells. Because a baby's liver can only break down a limited amount of bilirubin, the excess is passed on to you through the placenta to filter in your liver.

Other developments taking place this week:

  • Lips. Your baby will form distinct lips. 
  • Testes. If a boy, the testes, which have been tucked up inside the pelvis, will begin to descend into the scrotum this week, and immature sperm will form in the seminal vesicles.
  • Eyes. Your baby's eyes will complete formation, although the iris (the colored part of the eye) will still lack pigment.
  • Pancreas. Essential to insulin production, the pancreas will continue to develop steadily.

How you change

  • Weight gain. By now you may have gained 12 to 15 pounds. Starting this week you'll begin to put on weight more steadily, averaging about half a pound to a pound per week.
  • Contractions. This week you may also begin to notice your uterus practicing for delivery with an irregular, squeezing sensation called Braxton Hicks contractions.

Braxton Hicks

The term refers to an irregular tightening of the uterus that may get stronger and longer as pregnancy progresses. Near the end of your pregnancy it may be difficult to tell the difference between strong Braxton Hicks contractions and true labor pains. If the contractions become painful or if you have more than four contractions in an hour, contact your doctor. Painful regular contractions may be a sign of preterm labor.

Week 23: Baby's 8 to 9 inches long

How baby grows
Your baby continues to grow and by the end of this week will measure about 8 to 9 inches long. By week 23 your baby is taking on the shape of a full-term baby, but her bones and organs are still visible beneath a thin layer of translucent skin.

Your baby’s looking more like she will at birth! Translucent skin continues to develop, and fat deposits increase to help the skin look smoother.

Other developments this week:

  • More movement. She'll begin moving around more than ever, stretching and flexing the muscles in her arms and legs, fingers and toes.
  • Skin tone. Skin pigment is being deposited this week to create your baby's skin tone.

How you change

  • More bathroom breaks. As your uterus gets larger, it rests on top of the bladder, increasing your need to urinate frequently. 
  • Isolated pains. As you approach the end of your second trimester, your growing uterus may trigger more back pain, pelvic pressure, leg cramps and headaches.
  • Trouble sleeping. The closer you get to your delivery date, the more wakeful you may become. Anxiety, frequent urination, heartburn and general discomfort may result in restless nights. This uneasiness will most likely stop once your little one arrives.

Week 24: What a set of lungs!

How baby grows
Lung development takes a big leap forward this week as your baby prepares herself for a big cry upon arrival. Her lungs begin to produce surfactant, a wetting agent that will help her breathe correctly and keep her tiny lungs from collapsing or sticking together.
Blood vessels and air sacs are developing in the lungs and will eventually exchange oxygen and circulate it to all parts of her body.

She still has a lot of growing to do. At 1.2 pounds and 8 to 9 inches long, she may add at least another 5 pounds before birth for optimum health.

This week the following developments may occur:

  • Inner ear. This will become fully formed. Controlling balance, the inner ear means that your baby may be able to tell when she is upside down or right side up while floating in the amniotic fluid.
  • Touch. She will continue to explore her internal environment, flexing her fingers and touching her surroundings.

How you change

  • Heartburn. As your baby continues to grow, you may begin to get heartburn. During pregnancy heartburn is caused by hormonal and physical changes in your body. The growing baby can also push stomach acid up into the esophagus. 
  • You can help ease heartburn by eating five or six small nutritious meals a day. Also, try to avoid going to sleep right after eating.
  • Testing for gestational diabetes. Your doctor may recommend testing for gestational diabetes, a temporary type of diabetes that can occur during pregnancy. Women with gestational diabetes tend to have abnormally large babies, which can lead to difficulties during labor. In addition, gestational diabetes can cause low blood sugar and other problems in the baby after birth.

Good to know

If your blood sugar level is above a certain level, you'll have further tests. Gestational diabetes usually can be controlled with a special diet under your doctor’s supervision.

Week 25: Baby’s got a lot of nerve

How baby grows
At 1-1/2 pounds and a length of about 8 to 10 inches, your baby is growing at a steady pace.

The umbilical cord is thick and resilient now, covered in a firm, slippery substance that prevents kinking and knotting and may regulate the blood flow between placenta and baby.

During this week your baby is spending more time preparing for life after birth. Nerves around her mouth and lip area are becoming more sensitive, preparing her for that all-important task of finding a nipple and getting nourishment.

This week you could expect:

  • Fist-making. She will begin curling her fingers into a fist.
  • Dexterity. This will continue to develop as your baby learns how to control her hands.
  • Exploration. She'll continue to explore her surroundings, including the umbilical cord.
  • Spinal structure. Your baby's spinal structure will begin to form.
  • Open nostrils. Your baby's nostrils begin to open.

How you change

  • Light sensitivity. Your eyes may become sensitive to light, feeling gritty and dry. This is a perfectly normal pregnancy symptom called dry-eye. To ease your discomfort, try using an "artificial tears" solution.
  • Indigestion continues. You may develop (or continue to experience) indigestion. This is caused by the hormone progesterone slowing down the emptying of the stomach to allow for increased absorption of nutrients for your baby. Eating smaller, more frequent meals, and avoiding spicy and fatty foods may help ease this condition.

Week 26: Getting bigger!

How baby grows
Between now and Week 29 your baby will have a growth spurt and gain another pound. As your baby grows, space gets tighter inside the womb. Your baby now measures about 12.8 inches long and probably weighs almost 2 pounds.

Most of this weight is bone and tissue because she still doesn't have much body fat. In fact the main development of body fat doesn't really occur until late in the third trimester.

Developments that occur this week:

  • Eyelashes. These begin to grow as your baby begins to blink and open her eyes.
  • More hair. Hair continues to grow on her head.
  • Spine. To support her growing body, your baby's spine is getting stronger and more flexible.
  • Plumping up. Although she hasn't put on much fat, she is beginning to look a little plumper.

How you change

  • Weight gain. You've probably gained from 16 to 20 pounds by now, which includes your baby's weight, plus the weight of the placenta, enlarged uterus and breasts, amniotic fluid, and additional blood volume. There is also typical fat storage in mom's body that averages 4 to 7 pounds. 
  • Additional isolated pain. As the uterus enlarges and your baby gets bigger, you may notice more back pain, pelvic pressure, leg cramps, and headaches. Be sure to report any pains that even remotely feel like contractions to your doctor. Preterm labor (beginning before the baby is fully developed) is much easier to stop in the early stages.
  • Your baby's moving around. By now you can probably feel your baby moving every day, although not all babies are equally active. If you become concerned during those moments when you can't feel your baby move, try lying on your left side and being still. It's usually easier to feel fetal movement in that position.

Week 27: Baby opens her eyes!

How baby grows
This week marks the beginning of your third trimester.

A big developmental change occurs as your baby's fused eyelids finally open. They’ve been closed since early pregnancy to protect the developing retina at the back of the eye. The retina develops its normal layers during this week.

Although your baby may not have grown much taller, she now weighs more than 2 pounds. She looks like she will at birth, just a little thinner and smaller.

Other developmental changes happening:

  • Organs and systems. Lungs, liver, and immune system are still developing.
  • Hearing. As hearing continues to develop, some scientists suggest your baby may start to recognize your voice, although sounds may be muffled because a waxy coating still covers the ears. 
  • Response to sound. This will become more pronounced as the development of the auditory nerve is completed.
  • Brain. Her brain continues to grow and develop rapidly.

How you change

  • Loose hips. As your uterus has grown and you've gained more weight, your ligaments get looser in preparation for delivery, which can make your hips feel unstable or loose. This loosening and shifting may cause occasional sharp pains in your pelvic area. It's important to move slowly and deliberately, and avoid sudden movements.
  • Breathlessness. You may notice that it's getting increasingly hard to breathe as the uterus continues to expand near the rib cage, adding more pressure to your lungs. Getting a bit breathless is expected; but don’t worry, you and your baby are getting all the oxygen you need.
  • Memory and concentration issues. Due to hormonal changes—and everything that's on your mind, you may have trouble concentrating, keeping track of belongings, or remembering important things. Help yourself to feel more in control by trying to minimize stress, getting plenty of rest, and taking these brief memory lapses in stride.

Week 28: Getting brainy

How baby grows

This week marks an important milestone for your baby's brain development. Until now the surface of your baby's developing brain was smooth. During this week, your baby’s brain is beginning to develop the folds and fissures of the human brain, giving it the characteristic wrinkled-walnut appearance.

At about 2 pounds 4 ounces and 13.8 inches from head to toe, your baby has certainly come a long way!

Other important advances:

  • More fat. Your baby will continue to add layers of fat under her skin and will become plumper with each passing day.
  • More hair. Hair on your baby's head will continue to grow.
  • Testes. A boy's testes are usually completely descended into the scrotum by this point.
  • Labia. A girl's labia are still small and won't yet cover the clitoris. The labia will grow closer together in the last few weeks of pregnancy.
  • Lungs. Her lungs are now capable of breathing air.

How you change

  • Weight gain. By week 28 your uterus is about 3 inches above your belly button. Your weight gain may range from about 17 to 24 pounds.
  • Regular doctor visits. Starting now you'll probably be visiting your doctor every other week instead of every month. At your next appointment your doctor may be able to tell you how your baby is positioned in the womb.
  • Your baby's position. Ideally, soon you will feel her settle with her head pointed down toward your cervix—a sensation called "lightening."

Good to know

A baby in a head-up or breech position during labor may need to be delivered by cesarean section if the doctor can't turn her around. However, don't be alarmed at a breech presentation at this point—it's not that unusual. She still has two months to change position, which most babies do.

Week 29: Get a kick out of this

How baby grows
Now that organ and nerve development are almost complete, your baby will start gaining weight very quickly—mostly in the form of body fat. This fat will provide insulation for your baby and will fill out most of the wrinkles in her skin, making her look like a plump, healthy infant.

Your baby's brain continues its important developmental work this week. In fact it is growing so quickly now, it may cause her flexible skull bones to swell slightly. The folds and fissures of the brain continue to develop, allowing room for important interconnections between nerve cells. During this week brain wave patterns begin to look like those of a full-term baby.

By this time your baby may weigh just under 3 pounds and is a bit less than 14 inches long.

Other important developments in the 29th week:

  • Prolactin production. Your baby will begin to produce prolactin, a hormone that will help your body produce colostrum. Colostrum is the first breastmilk you'll produce and is filled with nutrients that help support a healthy immune system.
  • Kicking. Insistent kicking action will occur as your baby's muscles develop. Later in this trimester these movements will slow down as she gets bigger and the uterus gets more cramped.
  • Skeleton will continue to harden.
  • Lungs will continue to mature.
  • Loss of lanugo. Your little one's downy lanugo hair will begin to shed into the amniotic fluid. She may still have some on her body at birth, but this will fall off in the first week or so.
  • Toenails will continue to grow.
  • Retinas will continue to develop.

How you change

  • Weight gain. Your overall weight gain may be 19 to 25 pounds.
  • Nutritional needs. Your diet becomes even more important as your baby's nutritional needs peak. To keep your baby on track, you'll need plenty of protein, vitamin C, folic acid, iron and calcium. (About 200 milligrams of calcium is deposited into your baby's skeleton every day.) Dairy products, meat, fish, chicken, beans and tofu are good protein sources.
  • Additional isolated pains. The normal side effects of pregnancy may peak now—itchy skin (a result of hormones and stretching skin), hemorrhoids, breathlessness, fatigue, aching muscles, heartburn and leg cramps. 
    • In the second and third trimester, leg cramps usually occur at night. Although their exact cause is unknown, they may be linked to fatigue, pressure of the uterus on the nerves in the legs and inadequate calcium intake.

Week 30: Whoops! Hiccups!

How baby grows
As practice for breathing after birth, your baby mimics breathing movements by repeatedly moving her diaphragm in a rhythmic way. This can trigger hiccups if she inadvertently inhales amniotic fluid. A pint and a half of amniotic fluid now surrounds your baby, but that volume decreases as she gets bigger and has less room in your uterus.
Your baby has probably reached 3 pounds and about 14 inches in length. She’s also filling out a bit as she continues to gain weight, and these layers of fat help her to appear less wrinkled.

Here's what else is happening this week:

  • Head. Your baby’s head continues to grow, and brain growth speeds up even more.
  • Hearing. It’s improving; nearly all babies can react by movement to sound by this week.

How you change

  • Weight gain. At this point you may be gaining about a pound a week. Since the average weight gain during pregnancy ranges from 25 to 30 pounds, you may still have about 5 pounds to go.
  • Vivid dreams. By now you might be dreaming more vividly. These dreams may be related to your concerns about the new baby, your parenting ability (especially if this is your first child), and how life will be changing for your family. It's normal to have recurrent dreams about childbirth or unexpected experiences with your baby. 
  • Trouble sleeping. If you're finding it hard to sleep at night, try taking a catnap during the day to make up for it. If you work during the day, find a break room or safe, quiet place where you can get a little rest.

Week 31: Your baby's eyes have it!

How baby grows
This week marks some major changes for your baby's eyes. Most notably, her iris will become pigmented. However, no matter what color eyes your baby is born with (most are born with dark blue-brown or blue-gray eyes), the color almost always changes after birth. Your baby's true eye color won't appear for six to nine months after delivery. That's because the final eye pigmentation occurs in response to the strong light of the outside world. Also, your baby can open and close her eyes while awake or asleep.

By the end of this week your baby will weigh about 3.5 pounds and will be about 14.5 inches long. From now on your baby's weight gain will exceed her growth in length.
Each day brings new developments inside the womb:

  • Eyes. Your baby's eyes are now open during waking and are closed at naptimes.
  • Lungs. Your baby's lungs and digestive tract continue to develop.
  • Head-down position. As you near the end of the third trimester, your baby will begin to settle head-down into your pelvis. However, some babies don't make this journey until late in the last trimester, and about 4% of babies don't make the switch, remaining in a breech position at delivery.

How you change

  • Aches and pains. Aches and pains are fairly common at this stage of your pregnancy. 
  • Enlarging abdomen. As baby grows bigger each day, your abdomen enlarges. You may experience a mild ache in your rib cage and pelvis.
  • Swelling legs. You may experience additional swelling in your legs. Try to lie on your left side when sleeping or resting. 
    • When sitting you may want to tuck your legs to the side instead of in a crossed position because crossing your legs at the knee or at the ankle restricts blood flow to your legs.
  • Heartburn. You may experience even more heartburn this week as your uterus presses against your internal organs. You can relieve heartburn by remaining upright after eating, and by eating smaller, more frequent meals.
  • Leaking breasts. Some women begin to notice colostrum leaking from their breasts. If you’re experiencing this, you may want to use breast pads, which can help protect your clothes.
  • Continued hormone production. During this time your body continues to produce a number of hormones in preparation for labor and delivery.

Top tip

Loose-fitting clothing is also a good idea so you don't restrict blood flow in your arms and legs. Tight clothing at the waist, knees, ankles, shoulders, elbows, or wrists can cause problems.

Week 32: Baby’s changing her look

How baby grows
Your baby's appearance changes rapidly this week. Most of the wrinkles disappear from her face, and there may be a lot of hair on her head. In fact as the lanugo hair on her body begins to fall off, the hair on her head grows even faster. By week 32 some babies already have a thick head of hair while others have only a few strands.

Your baby is now about 4 pounds — an incredible increase of almost 2 pounds from last month—and about 15.5 inches long.

Other developments this week:

  • Nails. Your baby will have completely formed fingernails and toenails.
  • Head movement. She can turn her head from side to side.
  • Organs continue to mature.
  • Sucking. Your little one's sucking muscles have matured and enable her to latch on and breastfeed once she arrives. A good sucking pattern is also a sign of good brain and muscle development.
  • Dreaming. Her sleep will now include both REM and non-REM sleep stages. REM stands for "rapid eye movement," the dreaming stage of sleep.

How you change

  • Weight gain. You've probably gained about 3 to 4 pounds this month. Don't be alarmed—gaining a pound a week is quite normal during the last trimester because your baby's demand for nourishment increases as she experiences her final growth spurt before birth.
  • Numb and/or sensitive spots. As the skin on your belly expands, you may notice numb spots or highly sensitive areas on your upper abdomen or rib cage. This is because as your skin stretches, the nerve fibers in it stretch too. This can create extremely sensitive or insensitive areas on the skin, but this sensation will cease once your baby arrives.

Week 33: Getting a sense of things

How baby grows
In these last few weeks, billions of your baby's brain cells are helping her to learn about her environment. These cells help her to listen, feel and see.

This is another important week for visual development. By now your baby may be able to experience her surroundings visually, since the pupils can now detect some light. Her pupils constrict and dilate to allow your baby to see dim shapes.

Your baby now weighs about 4.4 pounds and is about 16.4 inches long from head to toe. She'll gain a good deal of her weight in the final few weeks before birth.

Other developments this week:

  • Head. Your baby's head size will increase about 3/8 of an inch in circumference this week.
  • Sleep time. Your little one now sleeps much of the time.
  • Lungs are continuing to mature.
  • Weight gain. Fat will continue to be added on to your baby's body for protection and warmth.
  • Testicles. For most boys, the testicles have now moved into the scrotum.

How you change

  • Head-down position. By this time the fetus should have turned around and begun to point head-down in the direction of the cervix. This will provide more space in the upper abdomen, making it easier for you to breathe. If you're a first-time mom, your child's head may move into the pelvis this week and press firmly against your cervix—this happens to about half of all first-time moms. If you've already had at least one child, this probably won't happen until about a week before labor. For some experienced moms, the baby won't move into position until the advanced stages of labor.
  • Weight gain. If you're gaining a pound a week now and your weight gain ranges from 22 to 28 pounds, you're right on track. Just about half of that weight goes right to the fetus. In fact the baby gains more than half its birth weight during the next seven weeks. Be sure not to stop eating or start skipping meals as your weight increases. Both of you need the calories and nutrition of a healthy diet.
  • Swelling. Although some swelling during the last trimester is completely normal, a sudden increase in swelling, combined with headaches, abdominal pain, nausea and vomiting should prompt you to contact your doctor immediately. These symptoms could be the signs of preeclampsia. Early diagnosis can help combat this complication.

Week 34: No more floating

How baby grows
As of this week your baby has grown so large, she takes up most of the available space inside the uterus and can no longer float around your womb. Your baby is now about 4.7 pounds and about 16.8 inches long.

This week, many babies have moved themselves into the correct “head-down” position for delivery indicating baby is getting ready for birth.

More developments this week:

  • Adrenal glands. Your baby's adrenal glands grow and produce corticoid hormones. Together with prolactin from the pituitary, they will stimulate lactation.
  • Skin. The vernix coating on your baby's skin grows thicker to better protect her. Your baby's skin gradually becomes less red and wrinkled as the fat beneath it fills out and stretches the skin.
  • Skull. Her skull bones are still quite pliable and not completely fused together at the top of her head. That will make it easy for her to slip down the relatively narrow birth canal.

How you change

  • Position check. Your doctor will want to check your baby's position in the womb. Because she's grown much larger, she's now tucked up and has probably moved into the proper head down position for birth. However, as late as week 34 a small percent of babies are still facing the other way, with their bottoms or legs toward the cervix. This is called a "breech presentation." At this late stage a baby can't usually turn around on her own, so your doctor will probably try to coax her into position by manipulating your lower abdomen. This should be performed in a hospital so you and baby can be monitored during the process.
  • Puffiness. You may have some additional puffiness in your feet, hands, face and ankles, especially during the evening or a warm spell. This puffiness is most likely caused by water retention. It may seem odd, but drinking more water can help ease water retention. If you're not getting enough water, your body sees your dehydration as a threat to your survival and begins to hold on to every drop.
  • Contractions. Braxton Hicks ("false labor") contractions may also intensify this week. Relax—it doesn't mean true labor is beginning. Increased pressure from your baby's head may make it seem as if she could suddenly emerge at any moment. This usually means your baby is pushing lower than usual into your pelvis. Be sure to talk to your doctor if you have any concerns at all.
    • This increased pressure also may cause a harmless numb or tingling feeling in the pelvic area. If you find it uncomfortable, you can try lying on your left side to help ease pressure. Lying on your left side is the best position, because it removes the pressure on arteries caused by your expanding uterus. Your doctor will continue to measure your uterus. It's important that your uterus enlarges at an appropriate, consistent rate.

Week 35: She’s adding healthy fat

How baby grows
Your baby will begin to gain weight more rapidly than ever … adding about an ounce each day from this point forward. Fat is being deposited all over your baby's body, especially around the shoulders.

In week 35 the average baby weighs around 5 to 6 pounds and measures about 16 to 19 inches in length.

Because of her size, your baby may move around less as her surroundings become more cramped. Her head may be resting on your pubic bone in preparation for labor and delivery.

Other developments taking place this week:

  • Central nervous system will continue to mature. 
  • Lungs. The lungs will most likely be fully developed by Week 35.
  • Activity. Your baby develops daily activity cycles. You may notice she is often more active at night, when you're trying to rest.
  • Respiratory and digestive systems. Even though they won't be considered full-term until the end of the 40th week, your baby's respiratory and digestive systems are nearly mature.
  • Immune system starts to develop.
  • Umbilical cord. It's now about 20 inches long and approaching 1/2 inch in diameter. At birth it will be about 2 feet long and a 1/2-inch thick.

How you change

  • Weekly doctor visits. Your doctor will probably want to start seeing you every week until you deliver. Starting now your doctor may begin regularly checking your cervix, looking for effacement and dilation rates and to check your baby's position. "Effacement" refers to how much your cervix has stretched and thinned, and "dilation" means how much the cervix is starting to open so your baby can move through the birth canal. (A cervix is fully dilated at 10 centimeters.) 
  • Between Weeks 35 and 37 your doctor also may test you for Group B streptococcus, an infection that can be passed on to newborns during birth.

Week 36: Gaining weight for the big day

How baby grows
Your baby now weighs 6 pounds and is 20.7 inches long.

Your baby works hard to accumulate all the fat she can in preparation for delivery. Her body grows rounder every day, since about 15 percent of her total weight is now made up of fat. Once she's born, this fat layer will help her maintain her body temperature and give her a reliable energy source.

Developments this week:

  • Organs. Development of major organs such as the kidneys and liver is complete.
  • Lungs. Some fine-tuning, such as the final development of the lungs, still takes place inside the womb.
  • Head. Your baby's head is round, but by the time she makes it through the birth canal it may be temporarily misshapen as powerful contractions compress the soft bones of the skull. Her head shape will return to normal within a few days.

How you change

  • Weight gain. You'll probably continue to gain weight, although the majority of your pregnancy weight gain has occurred.
  • Heartburn. If you've been experiencing heartburn, the baby's movement down toward your cervix may ease it. Your appetite may return because the baby is no longer putting as much pressure on your stomach and intestines.
  • Movements may change or cease. As your baby grows larger and amniotic fluid volume decreases, it's not as easy for her to move. It may feel as if the baby isn’t moving as much as before, but everything is usually fine. Things are just getting a bit crowded!

Week 37: It's getting crowded in there

How baby grows
Now baby weighs almost 6.5 pounds and her total length is about 21 inches long. But she hasn't stopped growing yet; she'll continue to develop about a half ounce of fat a day. Still, overall growth does slow from here on out. That's fortunate since there is very little available space left in the womb.

Here are a few final developments taking place in week 37:

  • Immune system. It continues to strengthen and will continue to get stronger after birth yet will not be completely functional until early adulthood.
  • Dexterity. Your baby can now grasp with her fingers as dexterity improves.

How you change

  • Vaginal discharge. You may experience heavier vaginal discharge this week, with more cervical mucus in it. Sometime during this week, as the cervix dilates in preparation for the labor, you may experience "bloody show." This thick, yellow, blood-streaked mucus plug had sealed off your uterus from infection and bacteria. As your cervix thins, it may drop out. 
  • Although some women never notice its departure, you may see thick discharge or stringy mucus tinged with blood. This light vaginal bleeding is considered to be an early sign of impending labor and can occur a few weeks, days or hours before contractions begin. Actual bleeding from the vagina, however, is abnormal and should be reported to the doctor immediately. 
  • Pelvic exam. At about this time your doctor may also perform a pelvic exam to evaluate your progress. To check for impending labor, some doctors may look for leaking amniotic fluid and examine your cervix to see whether it has softened or thinned out.

Week 38: Slowing down growth as the big day approaches

How baby grows
Although your baby's growth is slowing, fat will continue to accumulate, providing a thicker blanket of insulation in preparation for her entry into the outside world.

Your baby may weigh almost 7 pounds this week, but at a length of about 21 inches, she hasn't grown much taller. The average full-term newborn weighs from 6 to 9 pounds and is 18 to 21 inches long.

Here are some other developments this week:

  • Meconium (baby's feces). It will continue to build up in her intestines.
  • Head. By now the circumference of your baby's head and abdomen are about the same.

How you change

  • More bathroom breaks. As your baby puts more pressure on your bladder this week, your need to urinate increases.
  • How big is the baby? Since you're probably visiting your doctor on a weekly basis, you can ask for an estimate of the exact size of your baby.

Good to know

At this point, an ultrasound can provide a fairly accurate estimate of fetal weight by measuring the diameter and circumference of your baby's head and abdomen, and the length of the leg bone. But remember, this estimate can't predict how easily the baby will fit through your pelvis and the birth canal. Your doctor usually won't be able to tell whether your baby will move easily down the birth canal until labor actually begins.

Week 39: Almost there!

How baby grows
Even as late as the 39th week, there's one part of your baby's body that hasn't quite finished developing: the two soft spots on her head called the fontanels, where the skull bones haven't yet joined together. These areas allow the flexible skull bones to bend without damaging the brain as your baby travels down the birth canal.

Because of the strength of contractions during labor, many newborn heads look elongated or cone-shaped right after birth. The bones will return to their round shape within a few days after birth. During your baby's first year, the skull will harden; by 18 months the soft spots will have completely hardened.

Your baby’s skeleton also continues to develop. She now has 300 bones (about 100 more than an adult does, since some bones fuse together as the child grows).

How you change

  • Weight gain. Your pregnancy weight probably won't increase too much more from this point forward.
  • Contractions. Your body is preparing itself for labor, and you may begin experiencing Braxton Hicks contractions, which can be as strong as real contractions. Unlike real labor, these contractions are irregular and tend to stop and start. 
    • Although false contractions feel real, they aren't strong enough to make the cervix start thinning out or dilating. They may wax and wane for days or a few weeks before the onset of true labor. It can be hard to differentiate true and false labor, but contractions of true labor tend to get progressively stronger and more regular.
  • Water break. Another sign of labor—the rupture of your amniotic sac (water breaking)—could happen at any moment. When water breaks, the sensation you may feel can range from a startling gush of water to a steady trickle. Some women never notice their water breaking at all.

Week 40: Special delivery!

You may be ready to deliver this week. The average size of a baby born at 40 weeks is about seven pounds eight ounces.

How your baby has grown
The average birth weight for babies born at 40 weeks is about 7 pounds 8 ounces, and the average length is about 21 inches.

There are a number of surprising physical characteristics you may notice upon your little one's arrival. You may not have realized how your hormones can affect your baby at this stage. Because of the presence of your hormones in your baby's system, your baby's genitals (scrotum in boys and labia in girls) may appear enlarged. Your baby boy or girl may secrete milk from their tiny nipples. This is another hormone-related occurrence that should disappear in a few days and is completely normal. Finally, hormones may cause some "infant acne" pimples on your baby's face. These too will disappear within a month or so of birth.

Other developments:

  • Skin. Baby's skin can be very sensitive. When your baby is born it's normal for her to have skin discoloration; blotchy, dry skin; or even rashes.
  • Head shape. Your baby's trip through the birth canal will temporarily elongate her tiny head; this will round out within a few days.
  • No tears. Babies can cry at birth, but they are born with an underdeveloped tear duct system. You may notice that tears don't appear until 1 to 3 months of age.
  • Umbilical cord. After the cord is cut, a remnant will remain attached to the baby's abdomen. It will drop off within the first month.

Growing moments

Once your bundle of joy has arrived, GerberGrow lets you regularly log your baby’s weight and height, it can help you keep track of your beautiful baby’s growth.

How you have changed
When you're ready to deliver, you'll experience the following three basic stages of labor:

First stage: Your uterus contracts at regular intervals, thinning and stretching your cervix. This stage lasts the longest because the cervix must widen from zero to 10 centimeters.
The average duration of first-stage labor in women experiencing their first labors is about 12 hours. For moms who have experienced labor and delivery before, it may be half that long. However, first-stage labor can range from much shorter to much longer and still be considered normal.

Second stage: This is the time your baby moves through the vaginal canal and out of your body, due to a combination of uterine contractions and your pushing efforts. It usually lasts an hour or two with the first birth, but can be much shorter with later ones.

Third stage: The final stage of labor occurs when you deliver the placenta. After the baby has been delivered, the placenta separates from the uterine wall within about 10 minutes. Your doctor will massage your abdomen to help move the placenta along. Your doctor may need to reach inside and remove the placenta if it isn't expelled on its own.