Preterm labor occurs when regular contractions result in the opening of your cervix after week 20 and before week 37 of pregnancy.
Preterm labor can result in premature birth. The earlier premature birth happens, the greater the health risks for your baby. Many premature babies (preemies) need special care in the neonatal intensive care unit. Preemies can also have long-term mental and physical disabilities.
The specific cause of preterm labor often isn't clear. Certain risk factors might increase the risk, but preterm labor can also occur in pregnant women with no known risk factors. Understand the signs and symptoms of preterm labor and next steps.
Signs and symptoms of preterm labor include:
- Regular or frequent sensations of abdominal tightening (contractions)
- Constant low, dull backache
- A sensation of pelvic or lower abdominal pressure
- Mild abdominal cramps
- Vaginal spotting or light bleeding
- Preterm rupture of membranes — in a gush or a continuous trickle of fluid after the membrane around the baby breaks or tears
- A change in type of vaginal discharge — watery, mucus-like or bloody
When to see a doctor
If you experience these signs or symptoms or you're concerned about what you're feeling, contact your health care provider right away. Don't worry about mistaking false labor for the real thing. Everyone will be pleased if it's a false alarm.
Preterm labor can affect any pregnancy. Many factors have been associated with an increased risk of preterm labor, however, including:
- Previous preterm labor or premature birth, particularly in the most recent pregnancy or in more than one previous pregnancy
- Pregnancy with twins, triplets or other multiples
- Problems with the uterus, cervix or placenta
- Smoking cigarettes or using illicit drugs
- Certain infections, particularly of the amniotic fluid and lower genital tract
- Some chronic conditions, such as high blood pressure and diabetes
- Stressful life events, such as the death of a loved one
- Too much amniotic fluid (polyhydramnios)
- Vaginal bleeding during pregnancy
- Presence of a fetal birth defect
- An interval of less than six months between pregnancies
- Infection of tissues that surround and support your teeth (periodontal disease)
Complications of preterm labor include delivering a preterm baby. This can pose a number of health concerns for your baby, such as low birth weight, breathing difficulties, underdeveloped organs and vision problems. Children who are born prematurely also have a higher risk of learning disabilities and behavioral problems.
You might not be able to prevent preterm labor — but there's much you can do to promote a healthy, full-term pregnancy. For example:
- Seek regular prenatal care. Prenatal visits can help your health care provider monitor your health and your baby's health. Mention any signs or symptoms that concern you. If you have a history of preterm labor or develop signs or symptoms of preterm labor, you might need to see your health care provider more often during pregnancy.
- Eat a healthy diet. Some research suggests that a diet high in polyunsaturated fats (PUFAs) is associated with a lower risk of premature birth. PUFAs are found in nuts, seeds, fish and seed oils.
- Avoid risky substances. If you smoke, quit. Ask your health care provider about a smoking cessation program. Illicit drugs are off-limits, too.
- Consider pregnancy spacing. Some research suggests a link between pregnancies spaced less than six months apart and an increased risk of premature birth. Consider talking to your health care provider about pregnancy spacing.
- Be cautious when using assisted reproductive technology (ART). If you're planning to use ART to get pregnant, consider how many embryos will be implanted. Multiple pregnancies carry a higher risk of preterm labor.
If your health care provider determines that you're at increased risk of preterm labor, he or she might recommend taking additional steps to reduce your risk, such as:
- Taking preventive medications. If you have a history of premature birth, your health care provider might suggest weekly shots of a form of the hormone progesterone called hydroxyprogesterone caproate starting during your second trimester and continuing until week 37 of pregnancy. In addition, your health care provider might offer progesterone, which is inserted in the vagina, as a preventive measure against preterm birth. If you are diagnosed with a short cervix before week 24 of pregnancy, your health care provider might also recommend use of progesterone until week 37 of pregnancy.
- Managing chronic conditions. Certain conditions, such as diabetes and high blood pressure, increase the risk of preterm labor. Work with your health care provider to keep any chronic conditions under control.
If you have a history of preterm labor or premature birth, you're at risk of a subsequent preterm labor. Work with your health care provider to manage any risk factors and respond to early warning signs and symptoms.