The first trimester of a pregnancy is a time of incredible growth and development. A 7-week fetus will have begun to develop all essential organs.
Review Date 3/28/2019
Updated by: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.