Preterm Labor and Delivery
by Karen Schroeder Kassel, MS, RD, MEd
Preterm labor, or premature labor, is labor that occurs between the 20th and 37th week of pregnancy. A full-term pregnancy lasts 38-42 weeks. True labor includes both uterine contractions and cervical changes. Preterm labor can lead to preterm delivery. Babies who are born before 37 weeks are premature.
Preterm labor does not always lead to preterm delivery. Preterm labor can sometimes be stopped with a combination of medications and rest. If preterm labor cannot be stopped, your doctor will try to delay delivery. During this delay, you may be given corticosteroids to speed up the baby’s lung development. You may also be brought to a hospital with a neonatal intensive care unit (NICU).
Preterm birth is the number one cause of infants having serious health problems and death. About 11% to 12% of births in the US are premature—this translates to 1 in 8 births. Preterm babies have less time to develop in the uterus. As a result, they are at higher risk of medical problems. They are also at greater risk for death than babies born full term. The earlier a baby is born, the greater the risks. Babies born before 28 weeks are at greatest risk for health and developmental issues. These issues include:
Babies born between 28 and 32 weeks are at lower risk for complications, compared to those born prior to 28 weeks. Those born between 32 and 35 weeks usually have only short-term medical problems. The outlook for all preterm infants continues to improve with medical advances.
Often, the cause of preterm labor is not clear. However, several factors have been identified that increase the risk. It is essential for all pregnant women to know the signs of preterm labor. The quicker you are able to respond to these signs, the better chance that your doctor can delay or prevent preterm delivery.
What are the risk factors for preterm labor and delivery?
What are the symptoms of preterm labor?
How is preterm labor diagnosed?
What are the treatments for preterm labor?
Are there screening tests for preterm labor?
How can I reduce my risk of preterm labor and delivery?
What questions should I ask my doctor?
Where can I get more information about preterm labor and delivery?
American College of Obstetricians and Gynecologists, Committee on Practice Bulletins—Obstetrics. ACOG practice bulletin no. 127: Management of preterm labor. Obstet Gynecol. 2012;119(6):1308-1317.
Preterm labor. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115273/Preterm-labor . Updated January 2, 2018. Accessed March 7, 2018.
Preterm labor and birth: overview. National Institute of Child Health and Human Development website. Available at: https://www.nichd.nih.gov/health/topics/preterm/Pages/default.aspx. Updated January 31, 2017. Accessed March 8, 2018.
Preterm (premature) labor and birth. The American College of Obstetricians and Gynecologists website. Available at:
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Updated November 2016. Accessed March 7, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board Beverly Siegal, MD, FACOG
Last Updated: 3/15/2015
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