Your Unborn Baby's Development - Week By Week

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 baby develops from month to month.

After fertilization, the process of embryogenesis begins. By the end of the tenth week of gestational age the embryo has acquired its basic form and the next period is that of fetal development where the organs become fully developed.

Gestation is the period of time between conception and birth when a baby grows and develops inside the mother's womb. Because it's impossible to know exactly when conception occurs, gestational age is measured from the first day of the mother's last menstrual cycle to the current date. It is measured in weeks.

This means that during weeks 1 and 2 of pregnancy, a woman is not yet pregnant. This is when her body is preparing for a baby. A normal gestation lasts anywhere from 37 to 41 weeks.