Pregnancy Week by Week

Published on January 4th, 2018 and Updated on July 22nd, 2019

It takes just 40 weeks to grow a brand-new human, isn’t that amazing? There are so many changes taking place in your body—and your baby’s body—that it can feel overwhelming. But we’re here to help with this handy guide to your first, second and third trimesters. Know what to expect during pregnancy week by week and track your memorable journey into motherhood.

The First Trimester

Your body: During the first trimester, which encompasses weeks one to 13, your body will experience rapid changes, including breast tenderness, morning sickness and fatigue. You may experience some or all of these symptoms. You might also feel like you’re on an emotional roller coaster! Your mood swings may be partially hormonal, but who doesn’t experience a wide range of feelings when they are about to become a parent? This is also the time to schedule your first pre-natal appointment with your health-care provider.

Your baby: During the first trimester, your baby is developing in amazing ways. The spinal cord, brain and other internal organs are taking form, and you can hear your baby’s heart beating, always such a thrilling moment. By the end of this trimester, your baby will have fingerprints, be about three inches long and will weigh nearly an ounce!

The Second Trimester

Your baby: The second trimester, weeks 14 to 26, is Mother Nature’s gift to pregnant moms. This is when you’ll experience the fabled “pregnancy glow!”.

Your energy will return, your nausea will dissipate and you’ll start to show that adorable baby bump. This trimester also marks the halfway point, when you hit 20 weeks. Make sure you have regularly scheduled appointments with your doctor.

Your baby: It’s time to start talking, because your baby can hear you now! This is the time when you will also start to feel your baby moving, kicking and swimming. Your baby’s skeleton is hardening, changing from soft cartilage to strong bones and the baby’s eyelids and even eyebrows are now fully formed.

The Third Trimester

Your Body: The third trimester, weeks 27 to birth, can be challenging at times. Fatigue will return and it may be harder to sleep at night. You may also experience swelling in your ankles and backaches, and you might even begin to have pre-labor contractions, also known as Braxton-Hicks contractions. You’ll ramp up visits to your physician, with weekly appointments as you close in on your due date. But hang in there, it’s almost time to meet your little one.

Your Baby: Your baby is gaining weight like a champ, and the lungs are in the final phase of development. Your baby’s eyes can open and close and even follow a light! Those adorable layers of baby fat are in their final weeks of development, too. Don’t worry if you give birth a little bit early—baby is considered to be full-term by week 37.

You and your baby have been through 40 weeks of incredible change, but the wait is almost over. Soon, you’ll be holding your newborn in your arms!