Articles
Fetal development: The 1st trimester
Content
Weeks 1 and 2: Getting ready
Week 3: Fertilization
Week 4: Implantation
Week 5: Hormone levels increase
Week 6: The neural tube closes
Week 7: Baby's head develops
Week 8: Baby's nose forms
Week 9: Baby's toes appear
Week 10: Baby's elbows bend
Week 11: Baby's genitals develop
Week 12: Baby's fingernails form
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).