Preterm labor is labor that starts too early, between 20 and 37 weeks of pregnancy. It can be caused by a problem involving the baby, the mother, or both. But sometimes the cause isn't known.

The earlier delivery happens, the greater the chances are that the baby will have serious problems.

Current as of: November 14, 2014

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & William Gilbert, MD - Maternal and Fetal Medicine