The First Trimester

Healthy Pregnancy Home > Pregnancy > What Happens in Each Stage of Pregnancy > The First Trimester > Pictures

At 3.5 weeks:

• the fetus will have formed the heart
• begins development of the brain and spinal cord
• starts forming the gastrointestinal tract

At 7.5 weeks:

• the eyes move forward on the face and eyelids begin to form
• the palate is nearing completion and the tongue begins to form
• gastrointestinal tract separates from the genitourinary tract
• all essential organs have begun to form

At 8.5 weeks:

• the embryo now resembles a human
• facial features continue to develop
• beginnings of external genitalia form
• anal passage opens, but the rectal membrane is intact
• circulation through the umbilical cord is well developed
• long bones begin to form

A fetus at 10 weeks of development has fully formed eyelids and well-formed digits and ears.

A fetus at 12 weeks can make a fist and suck its thumb.

Current as of August 2006