Articles
Fetal development: The first trimester
Week 5: Hormone levels increase
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
Content
Weeks 1 and 2: Getting ready
Week 3: Fertilization
Week 4: Implantation
Week 5: Hormone levels rise
Week 6: The neural tube closes
Week 7: The head develops
Week 8: The nose forms
Week 9: Toes appear
Week 10: The elbows bend
Week 11: Genitals develop
Week 12: Fingernails form
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
Content
Weeks 1 and 2: Getting ready
Week 3: Fertilization
Week 4: Implantation
Week 5: Hormone levels rise
Week 6: The neural tube closes
Week 7: The head develops
Week 8: The nose forms
Week 9: Toes appear
Week 10: The elbows bend
Week 11: Genitals develop
Week 12: Fingernails form
Week 6: The neural tube closes
The sixth week of pregnancy, or four weeks after conception, the neural tube along your baby's back is closing. The brain and spinal cord develop from the neural tube. The heart and other organs also start to form.
Structures needed to form the eyes and ears develop. Small buds appear that will soon become arms. Your baby's body begins to take on a C-shaped curve.