Organs, nerves, and muscles start working together

Week 13: Your baby will start to focus on growth
By your 13th week of pregnancy, your baby's organs, nerves, and muscles have formed and are beginning to work together to help your baby grow.

• This week, your baby is probably about the length of a lemon.
• Eyes and ears are clearly defined. Your baby's eyelids are fused together to protect her still-developing eyes.
• Tissue, which will harden into bone, is developing in your baby's head, arms, and legs.
• Tiny ribs might be visible.
• She's already on the move. Your baby might be moving her body in jerky motions as she flexes her arms and kicks her legs, but you won't feel her move for at least several more weeks.
• Vocal chords develop.
• Your baby's circulatory system helps clear toxins from her body.
• When you're 13 weeks pregnant, your baby's head probably is about half the size of her body.

Your Week 13 nutrition and health

What to eat and avoid in week 13 and beyond

Eat

• Fresh or frozen fruits and vegetables: Theyíre packed with vitamins and minerals, such as vitamin C, which helps your body absorb iron. Plus, theyíre low in fat and are often a good source of fiber.
• Protein-packed foods: Foods such as lean meats, dried beans, and peanut butter are full of protein, which is essential to your babyís growth.

Fact: Different-colored fruits and vegetables have different levels of nutrients and vitamins. As a general rule, try to vary the types and colors of fruits and vegetables you eat every day.

Avoid

• Soft cheeses: Avoid feta, Brie, and blue-veined cheeses unless the label indicates that theyíre made with pasteurized milk.
• Shark, tilefish, king mackerel, and swordfish: These fish could contain high levels of mercury. Instead, eat fish that are low in mercury, such as salmon and catfish.

In your 2nd trimester, you're eating for two, and nutrition matters
Your baby is growing quickly. Remember to make healthy choices and get all the vitamins, minerals, nutrients, and calories you need to support your babyís growth and development. However, in your 2nd trimester, you only need to add about 340 calories a day to your diet. That's equivalent to 1 cup of skim milk plus one half of a peanut butter and jelly sandwich, or slightly larger portions of your normal meals.

What to expect at your next doctor visit

You might have another prenatal doctor visit during the 13th week of pregnancy or very soon after. From this point until you are about 28 weeks pregnant, most of your doctor appointments will follow a routine. Your doctor will monitor:

• Your weight and blood pressure
• Your urine (to check for proteins and sugars)
• Your baby's growth (by measuring the size of your uterus)
• Signs of swelling in your face, ankles, hands, or feet
• You might be hearing your baby's heartbeat for the first time during this visit. This is often possible after the 12th week of pregnancy.
• If you haven't decided about prenatal testing, now is a good time to discuss the options with your doctor.
• CVS (chorionic villus sampling) is one test that detects chromosome and other genetic abnormalities, usually between the 9th and 14th weeks of pregnancy. Learn more about prenatal screening and diagnostic testing.

Remember to bring your list of questions or concerns to each visit. If you have immediate concerns, discuss them with your doctor right away.