Preterm labor

Preterm labor occurs during pregnancy when the uterus regularly contracts before the 37th week of pregnancy, causing the cervix to open (dilate) and thin (efface).

Symptoms of preterm labor include pelvic or lower abdominal pressure; a persistent, dull ache in the lower back; menstrual-like cramps (with or without diarrhea); a change in the type or amount of vaginal discharge (sometimes a leak or gush of fluid); and regular or frequent tightening of the uterine muscle, often painless.

Early symptoms of preterm labor often are hard to diagnose. Commonly, the uterus will contract before true labor. These early contractions (Braxton Hicks contractions) do not dilate or efface the cervix but help prepare the uterus and fetus for labor. These contractions can be mistaken for preterm labor.

Before 20 weeks of pregnancy, preterm labor that leads to delivery is considered a miscarriage (spontaneous abortion). Very few premature infants will survive preterm birth at 23 weeks. Many hospitals do not resuscitate newborns born until 24 weeks of pregnancy because the chance of survival is extremely low.

Last Updated: January 14, 2009

Author: Sandy Jocoy, RN

Medical Review: Sarah Marshall, MD - Family Medicine & Deborah A. Penava, BA, MD, FRCSC, MPH - Obstetrics and Gynecology

related physicians

related services

Bon Secours International| Sisters of Bon Secours USA| Bon Secours Health System

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995-2010 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.