Weeks 14-18

Pregnancy (For Mom)
By Gerber

Pregnancy Development 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 time your doctor may talk to you about 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.


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.


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.


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.


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.