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 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 U.S. penny.
