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Preterm labor

Pregnancy complications - preterm


Labor that begins before week 37 is called "preterm" or "premature." About 1 out of every 10 babies born in the United States is born preterm.

A preterm birth is one of the major reasons babies are born disabled or die. But good prenatal care improves the chances that a preterm baby will do well.

What are the Signs and Symptoms of Preterm Labor?

You need to see a health care provider right away if you have:

What Causes Preterm Labor?

Researchers do not know what actually causes preterm labor in most women. However, we do know that certain conditions can increase the risk of preterm labor, including:

The mother's health problems or lifestyle choices that can lead to preterm labor include:

Problems with the placenta, uterus, or cervix that can lead to preterm labor include:

Lower Your Risk of Preterm Labor

To reduce your risk of preterm labor, follow your provider's advice. Call as soon as you can if you think you are having preterm labor. Early treatment is the best way to prevent preterm delivery.

Prenatal care lowers the risk of having your baby too early. See your provider as soon as you think you are pregnant. You should also:

It is even better to start seeing your provider if you are planning to have a baby but are not yet pregnant. Be as healthy as you can be before getting pregnant:

Women with a history of preterm delivery may need weekly injections of the hormone progesterone. Be sure to tell your provider if you have had a previous premature birth.

When to Call the Doctor

Call your provider right away if you notice any of these signs before your 37th week of pregnancy:

Your provider can do an exam to see if you are having preterm labor.

If you have preterm labor, you will need to be in the hospital. You may receive medicines to stop your contractions and mature your baby's lungs.


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Physical activity and exercise during pregnancy and the postpartum period: ACOG Committee Opinion, Number 804. Obstet Gynecol. 2020135(4):e178-e188. 2. PMID: 32217980

Rose J, Eiting E. Labor and delivery. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 176.

Simhan HN, Romero R. Preterm labor and birth. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 8th ed. Philadelphia, PA: Elsevier; 2021:chap 36.


Review Date: 4/19/2022  

Reviewed By: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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