Preterm Labor and Birth

What is preterm labor?

Preterm (premature) labor occurs when the uterus contracts and your cervix opens earlier than normal. The cervix is the opening of your uterus. In preterm labor, contractions are strong enough and occur often enough to allow the cervix to open for delivery of your baby. Preterm labor happens between week 20 and 37 of pregnancy. An early labor could cause you to have your baby before he or she is ready to be born.

What causes preterm labor?

The cause is sometimes unknown. The following may cause early labor:

• A large uterus or a short cervix can cause you to go into labor early.
• A chronic illness, such as high blood pressure, diabetes, or obesity, can cause early labor.
• An infection, such as a urinary tract infection or vaginal infection, can weaken the membranes (linings) of the amniotic sac around your baby. This could lead to premature rupture of the membranes and preterm labor.
• Problems with the placenta, such as placenta previa or placental separation, may cause preterm labor.
• Injury to your abdomen or uterus may also cause some cases of preterm labor.

What increases my risk for preterm labor?

• You are pregnant with two or more babies.
• You are under 17 or over 35 years of age.
• You get pregnant again less than six months after delivery.
• You had a preterm labor or preterm birth in the past.
• You did not have prenatal care.
• You smoke, drink alcohol, or use street drugs while pregnant.
• You are underweight. Too little weight gain during pregnancy may also increase your risk for early labor.

What are the signs and symptoms of preterm labor?

You may not know that you are having preterm labor. It is common to have preterm contractions (tightening and relaxing of the uterus) and not notice them. The following are signs and symptoms that suggest a preterm labor:

• Contractions that get stronger and closer together.
• Changes in vaginal discharge, such as more discharge or discharge that is watery or bloody.
• Low back pain.
• Pressure in the lower abdomen.
• Vaginal spotting or bleeding.

How is preterm labor diagnosed?

You may have one or more of the following tests to check for preterm labor:

• Pelvic exam: A pelvic exam is also called an internal or vaginal exam. During a pelvic exam, your healthcare provider will gently put a warmed speculum into your vagina. A speculum is a tool that opens your vagina. This lets your healthcare provider see if your cervix is opening.
• Vaginal ultrasound: A vaginal ultrasound uses sound waves to show pictures of your cervix and your baby inside your uterus. During this test, a small tube is placed into your vagina. This test will help your healthcare provider see if your cervix is opening.
• Fetal ultrasound: A fetal ultrasound uses sound waves to show pictures of your baby inside your uterus. The movement, heart rate, and position of your baby can also be seen.
• Fetal fibronectin: A fetal fibronectin test checks for a protein called fetal fibronectin in the cervix or vagina. Normally, there is no protein in cervical and vaginal secretions until the 20th week of pregnancy up to the end of pregnancy.
• Blood and urine tests: Blood and urine tests may be done to look for signs of infection.

How is preterm labor treated?

Early treatment of preterm labor may delay delivery.

• Bed rest may be recommended. You may need to lie on your left side, which improves circulation to your uterus and baby. Your healthcare provider will tell you when it is okay to get out of bed.
• Medicine may be given to stop contractions if your baby is not ready to be born. You may also need certain medicines if your preterm labor cannot be stopped and your healthcare provider thinks you will have your baby early. These medicines help your baby’s lungs, brain, and digestive organs mature. They also help decrease your baby’s risk of being born with cerebral palsy. Antibiotics may be given to treat a bacterial infection, if needed.

When should I seek immediate care?

• You have bright red, painless vaginal bleeding.
• Your symptoms do not get better or they get worse.
• Your water broke or you feel warm water gushing or trickling from your vagina.
• You have contractions that get stronger and closer together for more than one hour.
• You see or feel like there is something in your vagina.

When should I contact my healthcare provider?

• You notice a decrease in your baby’s movement.
• You have abdominal cramps, pressure, or tightening.
• You have a change in vaginal discharge.
• You have a fever.
• You have burning when you urinate or you are urinating less than is normal for you.
• You have questions or concerns about your condition or care.