Week 7: Baby's head develops

Seven weeks into your pregnancy, or five weeks after conception, your baby's brain and face are growing. Depressions that will give rise to nostrils become visible, and the beginnings of the retinas form.

Lower limb buds that will become legs appear and the arm buds that sprouted last week now take on the shape of paddles.

Week 8: Baby's nose forms

Eight weeks into your pregnancy, or six weeks after conception, your baby's lower limb buds take on the shape of paddles. Fingers have begun to form. Small swellings outlining the future shell-shaped parts of your baby's ears develop and the eyes become obvious. The upper lip and nose have formed. The trunk and neck begin to straighten.

By the end of this week, your baby might be about 1/2 inch (11 to 14 millimeters) long from crown to rump — about half the diameter of a quarter.

Week 9: Baby's toes appear

In the ninth week of pregnancy, or seven weeks after conception, your baby's arms grow and elbows appear. Toes are visible and eyelids form. Your baby's head is large but still has a poorly formed chin.

By the end of this week, your baby might be a little less than 3/4 inch (16 to 18 millimeters) long from crown to rump — the diameter of a penny.

Week 10: Baby's elbows bend

By the 10th week of pregnancy, or eight weeks after conception, your baby's head has become more round.

Your baby can now bend his or her elbows. Toes and fingers lose their webbing and become longer. The eyelids and external ears continue to develop. The umbilical cord is clearly visible.

Week 11: Baby's genitals develop

At the beginning of the 11th week of pregnancy, or the ninth week after conception, your baby's head still makes up about half of its length. However, your baby's body is about to catch up.

Your baby is now officially described as a fetus. This week your baby's face is broad, the eyes widely separated, the eyelids fused and the ears low set. Buds for future teeth appear. Red blood cells are beginning to form in your baby's liver. By the end of this week, your baby's external genitalia will start developing into a penis or clitoris and labia majora.

By now your baby might measure about 2 inches (50 millimeters) long from crown to rump — the length of the short side of a credit card — and weigh almost 1/3 ounce (8 grams).

Week 12: Baby's fingernails form

Twelve weeks into your pregnancy, or 10 weeks after conception, your baby is sprouting fingernails. Your baby's face now has taken on a more developed profile. His or her intestines are in the abdomen.

By now your baby might be about 2 1/2 inches (61 millimeters) long from crown to rump — the length of the short side of a U.S. bill — and weigh about 1/2 ounce (14 grams).

July 12, 2017 See more In-depth