Fetal development: The 1st trimester
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 a 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).