If a pregnant individual goes into labor before 37 weeks of pregnancy, this is considered preterm labor, and a baby born preterm might be at risk for certain health or developmental issues. Experts don’t know all of the reasons that preterm labor can occur, but they are aware of a number of risk factors that are associated with a higher risk of preterm labor.
Some risk factors include having experienced prior preterm labor or preterm birth, being pregnant with multiples, or the use of assisted reproductive technology, such as in vitro fertilization. Having a short time between pregnancies — less than 6 months between the birth of one child and the start of a new pregnancy — is also a risk factor.
There is also an increased risk of preterm labor associated with age (being younger than 18 or older than 35) and ethnicity — pregnant individuals who are African American, American Indian, and Alaska Native are more likely to experience preterm labor and birth than white individuals.
Other risk factors include certain medical conditions, such as: placenta previa (where the placenta grows low in the uterus and covers the opening to the cervix), being at risk for uterine rupture (which is more likely with a prior C-section or if uterine fibroids have been removed), diabetes or gestational diabetes, high blood pressure, vaginal bleeding, blood clotting issues, urinary tract infections (UTIs), some vaginal infections, sexually transmitted infections (STIs), reproductive organ abnormalities (such as a short cervix), and a weight prior to pregnancy that is either underweight or obese. There are some fetal developmental abnormalities that can mean a higher risk of preterm labor too.
There are also some lifestyle and environmental factors that are associated with a higher risk of preterm labor. These include smoking or substance abuse, domestic violence (physical, emotional, or sexual abuse), lack of social support during pregnancy, lack of prenatal care (either late care or no care), working long hours with long periods of standing, exposure to some particular environmental pollutants, and stress.
Certainly, some of these risk factors are things that pregnant individuals may be able to modify, while other risk factors can’t be changed. And it’s worth noting that sometimes premature labor can take place even without any of these risk factors at play or because other pregnancy complications arise. But while preterm labor can’t always be prevented, one of the best things you can do to care for yourself and your baby is continue to see your healthcare provider for consistent prenatal care and manage any health conditions that arise over the course of your pregnancy. Be sure to talk with your healthcare provider if you have any questions about your risk of preterm labor.
Reviewed by the Ovia Health Clinical Team
- “FAQ087: Preterm Labor and Birth.” American College of Obstetricians and Gynecologists. American College of Obstetricians and Gynecologists, January 2019. Retrieved December 9 2019. https://www.acog.org/Patients/FAQs/Preterm-Labor-and-Birth
- “Premature Birth.” Centers for Disease Control and Prevention. U.S. Department of Health & Human Services, October 17 2019. December 9 2019. https://www.cdc.gov/reproductivehealth/features/premature-birth/.
- “Preterm Labor.” Stanford Children’s Health. Stanford Children’s Health. Retrieved December 9 2019. https://www.stanfordchildrens.org/en/topic/default?id=preterm-labor-90-P02497.
- “What are the risk factors for preterm labor and birth?” Eunice Kennedy Shriver National Institute of Child Health and Human Development. National Institute of Health, January 31 2017. Retrieved December 9 2019. https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/who_risk