Preterm labor

Overview

Preterm labor happens when regular contractions cause the cervix to open after week 20 and before week 37 of pregnancy.

Preterm labor can result in a baby being born before 37 weeks of pregnancy. The earlier the delivery, the greater the health risks for the baby. Many premature babies, called preemies, need special care in a neonatal intensive care unit. Preemies also can have long-term mental and physical health concerns.

The cause of preterm labor often isn't clear. Certain risk factors can raise the chance of preterm labor. But preterm labor can happen with no known risk factors.

Symptoms

Symptoms of preterm labor include:

• Regular or frequent feelings of belly tightening, called contractions.
• Dull low backache.
• A feeling of pressure in the pelvis or lower belly.
• Mild belly cramps.
• Vaginal spotting or light bleeding.
• A gush or an ongoing trickle of fluid after the sac around the unborn baby, called the fetus, breaks or tears.
• Fluid from the vagina that is watery, bloody or filled with mucus.

When to see a doctor

If you have symptoms of preterm labor or you're worried about how you feel, contact your healthcare professional right away. Your healthcare professional can find out if you're in preterm labor or rule it out. Ruling it out could ease your mind.

Risk factors

Preterm labor can affect any pregnancy. But many factors can raise the risk of preterm labor. They include the following.

Medical history

• Preterm labor or premature birth in an earlier pregnancy. The risk is greater if this happened in the most recent pregnancy or in more than one pregnancy.
• Shortened cervix.
• Issues with the uterus or placenta.
• Certain infections. This is mainly true of infections of the amniotic fluid and lower genital tract.
• Some ongoing conditions, called chronic conditions. These include high blood pressure, diabetes, autoimmune disease and depression.

Pregnancy issues

• Pregnancy with twins, triplets or other multiples.
• Too much amniotic fluid. The medical term for this is polyhydramnios.
• Vaginal bleeding during pregnancy.
• Less than 18 months between pregnancies.
• Pregnancy before age 17 or after age 35.
• Pregnancy by way of assisted reproductive technology. This increases the risk of preterm labor whether it results in one fetus or more.

Other factors

• Smoking or illegal drug use.
• Stressful life events, such as the death of a loved one.
• Black race, non-Hispanic ethnicity.
• Poor nutrition or low pre-pregnancy weight.
• Lack of prenatal care.

Complications

Complications of preterm labor include having a premature baby. A baby who is born too early can have health issues. These may include low birth weight, trouble breathing, organs that are not fully formed, and trouble seeing and hearing.

Children who are born too early also have a higher risk of cerebral palsy, learning disabilities and behavioral problems. And preterm birth can be fatal for the baby.

Prevention

You might not be able to prevent preterm labor. But you can do things to support a healthy, full-term pregnancy. For example:

• Get regular prenatal care. Prenatal visits allow your healthcare professional to watch your health and your baby's health. At those visits, talk about any symptoms that worry you. If you have a history of preterm labor or have symptoms of preterm labor, you might need to see your health professional more often during pregnancy.
• Eat well. Healthy pregnancy outcomes often are linked with healthy eating.
• Don't use unhealthy substances. If you smoke, quit. Ask your healthcare professional about ways to help you quit. Don't use illegal drugs, either.
• Think about pregnancy spacing. Some research suggests a link between premature birth and pregnancies that start six months or less after the last delivery. Talk with your healthcare team about pregnancy spacing and birth control.
• Manage ongoing health conditions. Certain conditions that are ongoing, also called chronic, may raise the risk for preterm labor. Examples include diabetes, high blood pressure and obesity. Work with your healthcare team to control chronic conditions.

If you have a history of preterm labor or premature birth, you're at risk of preterm labor in later pregnancies. Work with your healthcare team to manage risk factors and respond to early symptoms of preterm labor.