Your baby can have problems if it is born too early. Serious illness or death can occur because the baby is not yet ready for life on his or her own. This pamphlet will explain:

The warning signs of preterm labor How to detect it at an early stage Methods used to help prevent preterm labor

The exact causes of preterm labor are not known. However, there are things you can do to improve your baby's chances of being born healthy.

What Is Preterm Labor?

Labor starts with regular contractions of the uterus. The cervix thins out (effaces) and opens up (dilates) so the baby can enter the birth canal. It is not known for certain what causes labor to start. Hormones produced by the woman, placenta, and fetus play a role. Changes in the uterus, which may be caused by these hormones, may cause labor to start.

There are many reasons for preterm labor. In most cases of preterm labor, however, the exact cause is not known.

Why the Concern?

Preterm birth accounts for most newborn deaths. Growth and development in the last part of pregnancy are vital to the baby's health. The earlier the baby is born, the greater the chance he or she will have health problems.

Preterm babies (also called premature babies or "preemies") tend to grow more slowly than term babies. They also may have problems with their eyes, ears, breathing, and nervous system. Learning and behavioral problems are more common in children who were preterm babies.

Signs of Preterm Labor

If preterm labor is found early enough, delivery may be prevented or postponed in some cases. This will give your baby extra time to grow and mature. Even a few more days may mean a healthier baby.

Sometimes the signs that preterm labor may be starting are fairly easy to detect. The box lists the early signs of preterm labor. If you have any of these symptoms, don't wait. Call your doctor's office or go to the hospital.

Diagnosing Preterm Labor

It is common for women to have Braxton Hicks contractions, sometimes called false labor, during the last part of pregnancy. These contractions may be painful and regular, but usually go away within an hour or so with rest. If you have contractions that occur 4 times every 20 minutes or if you have contractions 8 times an hour that last for more than an hour, call your doctor's office right away.

Warning Signs of Preterm Labor

Call your doctor or nurse right away if you notice any of these symptoms: Change in type (watery, mucus, or bloody) of vaginal discharge Increase in amount of discharge Pelvic or lower abdominal pressure Constant, low, dull backache Mild abdominal cramps, with or without diarrhea Regular or frequent contractions or uterine tightening, often painless Ruptured membranes (your water breaks with a gush, or sometimes even a trickle of fluid)

Preterm labor can be diagnosed only by finding changes in the cervix when you are having regular contractions. This means your doctor will have to examine you. To help diagnose preterm labor your doctor may use the following tests:

• Fetal monitoring. These tests are used to record the heartbeat of the fetus and contractions of your uterus.
• Ultrasonography. This exam may be used to measure the length of the cervix and estimate the size, age, and position of the fetus. You may be watched for a time and then examined again to see whether your cervix changes.
• Fetal fibronectin. This test is used to measure the amount of a certain protein that helps predict the risk of preterm delivery.

Women at Risk

Preterm labor can occur without warning. Some women are at greater risk for preterm labor than others. Women who have little or no prenatal care and those who have had preterm labor before are at increased risk.

A number of other factors have been linked to preterm labor (see box). For instance, too much amniotic fluid in the sac that surrounds the baby is a risk factor. Problems with the placenta or certain birth defects also increase the risk. Certain health factors also may be linked to an increased risk for preterm birth:

• Short cervical length as measured by ultrasonography
• Increased amounts of the protein fetal fibronectin in vaginal discharge

• Changing your lifestyle (see box)
• Having more frequent visits with your doctor
• Learning how to check your contractions

Risk Factors for Preterm Labor Check any box that applies to you: You have warning signs of preterm labor. You have had preterm labor during this pregnancy. You had preterm labor or preterm birth in a previous pregnancy. You smoke cigarettes or use cocaine. You are carrying more than 1 baby. You have an abnormal cervix (due to surgery, for instance). You have an abnormal uterus. You have had abdominal surgery during this pregnancy. You have had an infection while pregnant. You have had bleeding in the second or third trimester of your pregnancy. You are underweight. You had a mother or a grandmother who took DES (diethylstilbestrol, a medication given to many pregnant women in the 1950s and 1960s). You have had little or no prenatal care. You have a child with chromosomal disorders. If you checked any of these boxes, you may be at risk for preterm labor. Despite what is known about these risk factors, much remains to be learned about preterm labor. Half of the women who go into preterm labor have no known risk factors.

In many cases, women at risk for preterm labor do not have to take leave from their jobs. However, you may be advised to avoid heavy lifting or other hard or tiring tasks during pregnancy.

If you take childbirth preparation classes, tell the teacher you are at risk for preterm labor. He or she may advise you to skip certain exercises. Women at risk also may be advised to cut down on travel. Ask your doctor about these and other changes you may need to make in your daily routine.

If you have a history of preterm labor or have signs of preterm labor, you may wonder about having sex during pregnancy. Many women worry that the uterine contractions that often follow sex and orgasm will lead to preterm labor. Although in most cases the contractions stop, these are natural and real concerns that should be discussed with both your partner and your doctor. You may be advised to restrict sexual activity or to monitor yourself for contractions after sex.

Monitoring for Contractions

After about 20 weeks of pregnancy, you may be asked to monitor yourself for signs of uterine activity or tightening. To monitor yourself, lie down on your side and gently feel the entire surface of your lower abdomen with your fingertips. You are feeling for a firm tightening over the surface of your uterus. In most cases, these feelings of tightening are not painful.

If you feel contractions, keep monitoring for an hour. Keep track of when each contraction starts and ends and the total number that occur in 1 hour. Having some uterine activity before 37 weeks of pregnancy is normal. If your contractions occur 4 times every 20 minutes or you have 8 contractions in an hour, you need to call your doctor right away. You may be in preterm labor. You should contact your doctor or nurse each time you have 8 or more contractions per hour, unless he or she has advised otherwise.

Treatment

Sometimes contractions can be stopped for at least 48 hours. Other times, the baby must be delivered. Your doctor may try to stop labor if:

• It is detected early enough
• You and your baby are not in danger from infection, bleeding, or other complications

Changing Your Lifestyle Some studies have found that certain lifestyle factors may increase a woman's risk of preterm labor. In these cases, there may be things you can do during pregnancy to help decrease your risk of preterm labor: Get prenatal care Do not smoke or use illegal drugs

If it looks as though you may have the baby early, you may be given a medication called a corticosteroid. This substance crosses the placenta and helps the baby's lungs mature and increases the baby's chance to live. Studies suggest that corticosteroids are most likely to help your baby when given between 24 and 34 weeks of pregnancy.

You may be able to go home if you are not really in preterm labor or if labor is stopped, or you may need to stay in the hospital for a while. This depends on what the doctor's exam reveals.

If you have had preterm labor, your doctor may suggest limits on activity. The type of activity limits can vary.

Preterm Delivery

Sometimes preterm labor may be too far along to be stopped, or there may be reasons that the baby is better off being born, even if it is early. These can include:

• Infection
• High blood pressure
• Bleeding
• Signs that the fetus may be having problems

Preterm babies may not be ready to live on their own. They may be cared for in a neonatal intensive care unit (NICU) for weeks and sometimes months. Preterm babies often are kept in an incubator to keep them warm. They are cared for by specially trained nurses and doctors. Today, with special NICU care, even very early, tiny babies have a chance of survival.

Finally...

The exact causes of preterm labor are not known. However, there are things you can do to have a healthy pregnancy:

• Get regular prenatal care
• Eat healthy foods and do not skip meals
• Lead a healthy lifestyle
• Be alert to signs of preterm labor
• Follow your doctor's advice

Glossary

Amniotic Fluid: Fluid in the sac surrounding the fetus in the woman's uterus.

Cervix: The lower, narrow end of the uterus.

Corticosteroid: Hormones given to mature fetal lungs, for arthritis, or other medical conditions.

Fetal Fibronectin: A protein produced during pregnancy.

Fetal Monitoring: A procedure in which instruments are used to record the heartbeat of the fetus and contractions of the mother's uterus during labor.

Fetus: A baby growing in the woman's uterus.

Placenta: Tissue that provides nourishment to and takes away waste from the fetus.

Prenatal Care: A program of care for a pregnant woman before the birth of her baby.

Progesterone: A female hormone that is produced in the ovaries and makes the lining of the uterus grow. When the level of progesterone decreases, menstruation occurs.

Tocolytic: Medication used to stop or slow preterm labor.

Ultrasonography: A test in which sound waves are used to examine internal structures. During pregnancy, it can be used to examine the fetus.

Uterus: A muscular organ located in the female abdomen that contains and nourishes the developing embryo and fetus during pregnancy.

This Patient Education Pamphlet was developed under the direction of the Committee on Patient Education of the American College of Obstetricians and Gynecologists. Designed as an aid to patients, it sets forth current information and opinions on subjects related to women's health. The average readability level of the series, based on the Fry formula, is grade 6–8. The Suitability Assessment of Materials (SAM) instrument rates the pamphlets as "superior." To ensure the information is current and accurate, the pamphlets are reviewed every 18 months. The information in this pamphlet does not dictate an exclusive course of treatment or procedure to be followed and should not be construed as excluding other acceptable methods of practice. Variations taking into account the needs of the individual patient, resources, and limitations unique to the institution or type of practice may be appropriate.

Copyright © July 2004 by the American College of Obstetricians and Gynecologists. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher.

ISSN 1074-8601

Requests for authorization to make photocopies should be directed to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923.

To reorder Patient Education Pamphlets in packs of 50, please call 800-762-2264, ext 830, or order online at sales.acog.org.

The American College of Obstetricians and Gynecologists
409 12th Street, SW
PO Box 96920
Washington, DC 20090-6920

12345/87654