Risk Factors for Premature Labor and Birth

Preterm or premature birth

Premature birth (preterm birth or having a "preemie") is a delivery before 37 completed weeks of the pregnancy.  Preterm labor or other complications such as premature rupture of fetal membranes or multiples can lead to premature birth. Premature birth is the #1 reason for neonatal morbidity and mortality. About 75% of neonatal deaths are due to babies born too early.

Newborns and babies who are born too early are more likely to have more health problems than babies born on time. These complications include lung, brain, and bowel issues. 

Some women are more likely than others to have preterm labor and premature birth. They are at risk for premature births. In certain conditions, it's possible to reduce your risk factors to help make you less likely to have preterm labor.

Calculate your risk of premature and preterm birth here!

One step in preventing preterm births is to learn the signs of preterm labor and what to do if they happen to you.

Risk factors for preterm and premature births

Often, the specific cause of premature birth isn't clear. Black women are more likely to experience premature birth than are women of other races. But premature birth can happen to anyone. In fact, many women who have a premature birth have no known risk factors. The following are risk factors that can make it more likely to have preterm labor and give birth early:

• Previous premature birth
• Previous premature rupture of fetal membranes
• Being pregnant with multiples (twins, triplets, or more). 
• Prior or present problems with your uterus and/or cervix 
• An interval of fewer than six months between pregnancies
• Conceiving through in vitro fertilization
• Problems with the uterus, cervix, or placenta
• Smoking cigarettes or using illicit drugs
• Some infections, particularly of the amniotic fluid and lower genital tract.
• Having certain health conditions, like high blood pressure, preeclampsia, diabetes, or thrombophilias (blood clotting disorders)
• Being underweight or overweight before pregnancy
• Stressful life events, such as the death of a loved one or domestic violence
• Multiple miscarriages or abortions
• Physical injury or trauma
• Having a family history of premature birth. This means someone in your family (like your mother, grandmother, or sister) has had a premature baby. If you were born prematurely, you’re more likely than others to give birth early.

African-American women in the US are at increased risk for delivering preterm

In the United States, African-American women are more likely to give birth before 37 weeks. Almost 17 percent of African American babies are born prematurely each year. Just more than 10 percent of Native American and Hispanic babies are born early, and less than 10 percent of white and Asian babies. 

While African-Americans are at increased risk of delivering a preemie, race itself is not necessarily the root cause of preterm birth. There are factors associated with being African-American in the US including experiencing institutional racism, racial health inequities, higher psychosocial stress, inadequate access to health care, etc which contribute to the increased rate of preterm births in African-American women

Risk factors for preterm labor and premature birth during pregnancy

• Bleeding from the vagina in the second or third trimester 
• Preterm premature rupture of the membranes (also called PPROM). This is when the sac around the baby breaks early, causing labor to start.
• Being pregnant after in vitro fertilization (also called IVF). IVF is a fertility treatment used to help women get pregnant. 
• Being pregnant with a baby who has certain birth defects, like congenital heart defects or spina bifida.
• Getting pregnant too soon after having a baby. Wait at least 18 months between giving birth and getting pregnant again. Talk to your provider about how long to wait between pregnancies if you're older than 35 or you've had a miscarriage or stillbirth. Miscarriage is the death of a baby in the womb before 20 weeks of pregnancy. Stillbirth is the death of a baby in the womb after 20 weeks of pregnancy. 

Risk factors in your everyday life for preterm labor and premature birth

• Smoking, drinking alcohol, using street drugs, or abusing prescription drugs
• Having a lot of stress in your life, including having little education, low income, being unemployed, or having little support from family and friends 
• Being single
• Domestic violence: This is when your partner hurts or abuses you. It includes physical, sexual, and emotional abuse
• Working long hours or having to stand a lot
• Being exposed to pollutants, like air pollution and harmful chemicals at work 

Other risk factors for preterm labor and premature birth

• Age and race/ethnicity. Being younger than 17 or older than 35 makes you more likely than other women to give birth early.

Early identification of risk factors is crucial in finding out whether something can be done to prevent premature births. Prevention of premature birth is, therefore, an important part of prenatal care.

Read More:
Preterm Delivery Risk Calculator
The Effects of Premature Labor on Your Baby
Labor, Delivery, and Birth Guide