Pregnancy and Fetal Development
Picture of First Trimester (4 Weeks)
First Trimester: The Baby at 4 Weeks
- Your baby's brain and spinal cord have begun to form.
- The heart begins to form.
- Arm and leg buds appear.
- Your baby is now an embryo and 1/25 of an inch long.
Related Topics
Stages of Pregnancy Slideshow
Reviewed by William C. Shiel Jr., MD, FACP, FACR on August 21, 2009
Image Source: Copyright © Medical RF / Phototake -- All rights reserved.
Text: Womenshealth.gov - Healthy Pregnancy: Stages of Pregnancy
Image Source: Copyright © Medical RF / Phototake -- All rights reserved.
Text: Womenshealth.gov - Healthy Pregnancy: Stages of Pregnancy