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URL of this page: //medlineplus.gov/ency/imagepages/17178.htm
First trimester of pregnancy
Overview
The first trimester of pregnancy is the first three months after conception. Signs of early pregnancy are missed menstrual periods, fatigue, breast enlargement, abdominal distention, and nausea. During this period of time all organ development takes place so the fetus is most susceptible to damage from toxins, drugs, and infections.
Review Date 5/22/2025
Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
