SPECIAL OFFER: - Limited Time Only!
(The ad below will not display on your printed page)

Your Developing Baby, Week by Week

Your baby begins as a tiny cluster of cells, but during the nine-month process of pregnancy she becomes an amazing baby with facial features, a beating heart and kicking legs. Find out what's happening with baby's development week by week.
week 4 Week 4

So what's going on in your womb this week? Your embryo may be minuscule, but trust us: Super-important developments are already under way. This week the embryo splits into two parts. One half will become the placenta, a special tissue that delivers must-have nutrients and oxygen to your baby throughout your entire pregnancy. In the other half, the embryo itself continues to grow, and a sheet of cells has just begun to create the neural tube, where your baby's brain, spinal cord and backbone will ultimately form.