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Contractions help your cervix dilate -- or open -- so your baby can pass through the birth canal. You're fully dilated when your cervical opening measures 10 centimeters. As the cervix opens, it also thins (effaces) in preparation for delivery.
Review Date 11/8/2024
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.
