Fetal Growth: Conception to Birth
You're pregnant. Congratulations! Are you curious how big your developing baby is, what your baby looks like as it grows inside you, and when you'll feel it move? Take a peek inside the womb to see how a fetus develops from month to month.
Conception
If a sperm cell meets and penetrates an egg, it will fertilize it. This is known as conception. At this moment, the genetic makeup is complete, including the sex of the infant. Within about three days after conception, the fertilized egg, which is dividing rapidly into many cells, passes through the fallopian tube into the uterus, where it attaches to the uterine wall. The placenta, which will nourish the baby, also begins to form.
Fetal Development at 4 Weeks
At this point of development the structures that eventually form the face and neck are becoming evident. The heart and blood vessels continue to develop. And the lungs, stomach, and liver start to develop. A home pregnancy test is now positive.
