Fetal Development

From a tiny cluster of cells to a bouncing baby - fetal development is an amazing process. Here you'll see pictures of how a fetus develops each week, and each trimester. Plus what's happening to your baby throughout the fetal development process.

Sperm Meets Egg: Weeks 1 to 3 of Pregnancy

Something magical is about to happen! Watch as the ovulation process occurs, and then millions of sperm swim upstream on a quest to fertilize an egg.

First Trimester: Images of Your Developing Baby

Do you know what to expect in the first trimester of pregnancy? We've partnered with the American Institute of Ultrasound Medicine (AIUM), Johns Hopkins, and the March of Dimes to create this unique peak into Baby's development inside the womb during the first trimester. These images reveal all the intricate details of your baby's growth. While most women normally receive one or two ultrasounds during pregnancy, this slideshow of the first trimester of pregnancy gives you a look at each week of development.

Second Trimester: Images of Your Developing Baby

We've partnered with the American Institute of Ultrasound Medicine (AIUM), Johns Hopkins, and the March of Dimes to create this unique peak into Baby's development inside the womb. These images reveal all the intricate details of your baby's growth -- from a collection of cells to a full-term newborn. While most women may only receive one or two ultrasounds during pregnancy, which is normal, this slideshow of the 2nd trimester of pregnancy gives you a look at each week of development.

Embryo to Fetus: Weeks 9 to 12 of Pregnancy

You're well into your first trimester at this point, and your baby is growing bigger and bigger each day. Watch what it takes for her to become a fetus.

Third Trimester: Images of Your Developing Baby

We've partnered with the American Institute of Ultrasound Medicine (AIUM), Johns Hopkins, and the March of Dimes to create this unique peak into Baby's development inside the womb. These images reveal all the intricate details of your baby's growth -- from a collection of cells to a full-term newborn. While most women may only receive one or two ultrasounds during pregnancy, which is normal, this slideshow of the 3rd trimester of pregnancy gives you a look at each week of development.

Twins: A Closer Look at Your Developing Babies

Parents.com partnered with the American Institute of Ultrasound Medicine (AIUM) to create this unique peak into a baby's development inside the womb. These images reveal all the intricate details of a baby's growth -- from a collection of cells to a full-term newborn. While most women may only receive one or two ultrasounds during pregnancy, which is normal, this slideshow of the 3rd trimester of pregnancy gives you a look at each week of development.

Growing Big: Weeks 31 to 34 of Pregnancy

Your baby now weighs about three pounds, roughly the size of a melon. Get the scoop on how much more she'll grow before she's born--and what new developments she's making right now.

Fetal Movement: Feeling Baby Kick

Experts answer your top questions about your developing baby's movements, from when she'll start kicking to how often you should feel her kick.

How Big Is Your Baby in Second Trimester?

Wonder how big your baby is now? Here's an approximate look at size, weight and height in the second trimester.

Fetal Development Weeks 31 Through 35

See what's happening with your baby in the eighth month of your pregnancy.

This NFL Star and His Wife Had a Prenatal Testing Scare--Now They're Talking About It

Pro football star Torrey Smith, whose wife is pregnant with baby #2, wrote an honest blog post about their anxiety-inducing prenatal test results.

Study Shows Language Development Starts in the Womb

New research reveals that babies in the womb can already distinguish between different languages.

Week 28 Ultrasound: What It Would Look Like

You've reached the final trimester of pregnancy! Learn all about the important milestones you can expect from baby and your own body while 28 weeks pregnant.

An Embryo Forms: Weeks 4 to 8 of Pregnancy

Chances are you have no idea you're pregnant yet-but your body is already hard at work. Watch as the egg undergoes its wondrous transformation to embryo.

Baby's Alertness in the Womb

Learn how your baby moves and experiences life in the womb.

Fetal Development Weeks 9 Through 13

See what's happening with your baby in the third month of your pregnancy.

The Inside Story: Your Baby in Weeks 1 Through 4

Your pregnancy has started -- even though you may not know it. Find out what's going on right now during your baby's very first weeks of life in utero.

Fetal Development Weeks 1 Through 4

See what's happening with your baby in the first month of your pregnancy.

Week 18 Ultrasound: What It Would Look Like

When you're 18 weeks pregnant, you can get your most detailed ultrasound to date. Here, get a breakdown of exactly what the sonographer will check for during this examination.

Sleep Cycles: Weeks 26 to 30 of Pregnancy

At this point, your baby is awake and asleep at very specific times of the day. Find out about his sleep patterns, and what they mean.

Week 6 Ultrasound: What It Would Look Like

What's going on with your baby during week six of pregnancy? Find out the baby's size and what goes on inside of you during this week-by-week journey.

Week 30 Ultrasound: What It Would Look Like

Your baby is making new brain cell connections as your 30th week of pregnancy begins. Find out all the exciting new developments during this part of your journey.

Feeling Baby Move: Weeks 18 to 21 of Pregnancy

You'll start feel your baby's fluttering movements (called quickening) between now and 22 weeks. Get ready, mama: Feeling him kick is one of the most magical parts of being pregnant.

How Big Is Your Baby in Third Trimester?

Wonder how big your baby is now? Here's an approximate look at size, weight and height in the third trimester.

How Big Is Your Baby in First Trimester?

Wonder how big your baby is now? Here's an approximate look at size, weight and height in the first trimester.