Week 31: Your pregnancy

Your baby's growth: Your baby's eyes have color

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.

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.

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 second 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 percent of babies don't make the switch, remaining in a breech position at delivery.

What's happening with you

• Aches and pains. Some aches and pains are fairly common in and around your 31st week of pregnancy.
• Enlarging abdomen. As baby grows bigger each day, your abdomen enlarges. You may experience a mild ache in your rib cage and pelvis. Your total pregnancy weight gain by this time should be somewhere between 21 and 27 pounds.

• Swelling legs. You may also be experiencing additional swelling in your legs. Try to lie on your left side when sleeping or resting.

  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.

  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. Also this week some women begin to notice colostrum leaking from their breasts. If you are 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.