4 Weeks Gestation

• The brain and the spinal cord begin to form.
• The heart begins to form.
• The stomach and intestines are forming.
• Bone tissue is growing.
• The eyes and ears are just beginning to form.
• The weight is less than one ounce.
• The length is less than 1/8 inch.

© 2003 Texas Department of Health. All rights reserved. Photos: Lennart Nilsson / Albert Bonniers Forlag AB, A Child Is Born, Dell Publishing Company. Used by permission.