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Normal pregnancy: First trimester

Detail showing development of embryo in uterus at 8th week and fetus at 12th week

The first trimester of pregnancy lasts from the first day of your last menstrual period through week 13.

Current as of: June 16, 2021

Author: Healthwise Staff
Medical Review:
Sarah Marshall MD - Family Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Kirtly Jones MD - Obstetrics and Gynecology
Heather Quinn MD - Family Medicine