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Preterm labor

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

A preterm birth is one of the major reasons why 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 see a doctor right away if you have:

  • Spotting and cramps in your belly together
  • Contractions with lower back pain or pressure in your groin or thighs
  • Fluid that leaks from your vagina in a trickle or a gush
  • Bright red bleeding from the vagina
  • A thick, mucous discharge with blood in it
  • Your water breaks (structured membranes)
  • More than 5 contractions per hour, or contractions that are regular and painful
  • Contractions that get longer, stronger, and closer together
  • Cramps in your belly

What Causes Preterm Labor?

Problems or test results that occur during the pregnancy and can lead to preterm labor include:

  • Twins
  • Infection in the mother or in the membranes around the baby
  • Certain birth defects
  • High blood pressure in the mother
  • When the bag of water breaks early
  • Too much amniotic fluid
  • First trimester bleeding

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

  • Cigarette smoking
  • Illegal drug use, often cocaine and amphetamines
  • Physical or severe psychological stress
  • Poor weight gain during pregnancy
  • Obesity

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

  • When the cervix does not stay closed on its own (cervical incompetence)
  • When the shape of the uterus is not normal
  • Poor function of the placenta, placental abruption, and placenta previa

Lower Your Risk of Preterm Labor

To reduce your risk of preterm labor, follow your doctor’s advice. Call your doctor as soon as you can if you think you are having preterm labor.

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

  • Get routine checkups throughout your pregnancy.
  • Eat healthy foods.
  • Not smoke
  • Not use alcohol and drugs

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

  • Tell you midwife or doctor if you think you have a vaginal infection.
  • Keep your teeth and gums clean before and during pregnancy.
  • Make sure to get prenatal care, and keep up with recommended visits and tests.
  • Reduce stress during your pregnancy.
  • Avoid non-pasteurized (“raw”) meats and cheeses (which carry a risk for listeria infection).
  • Talk to your doctor or midwife about other ways to stay healthy.

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

When to Call the Doctor

Call your doctor right away if you notice any of these signs before your 37thweek of pregnancy

  • Cramps, pain, or pressure in your abdomen (belly)
  • Spotting, bleeding, mucous, or watery fluid leaking from your vagina
  • Sudden increase in vaginal discharge

Your doctor or midwife can do an exam to see if you are having preterm labor.

  • An exam will check to see if your cervix has dilated (opened) or if your water has broken.
  • Your doctor may use a monitor to check your contractions.
  • If you have a fluid discharge, it will be tested. The test may help your doctor know if you will deliver early or not.

Update Date: 4/22/2012

Updated by: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

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