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Risk Factors for Preterm Labor and Delivery

  • Cynthia M. Johnson, MA
Publication Type:

Condition InDepth

Risk Factors for Preterm Labor and Delivery

A risk factor is something that raises a person's chances of getting a disease or health problem. A woman can have preterm labor with or without the risks below. The more risks a woman has, the greater the chances are.

Preterm labor is more common in women who:

  • Are Black
  • Are pregnant with more than one baby
  • Have used assisted reproductive technologies
  • Are under the age of 16 years old

Some things that may raise the risk are:

  • Prior premature birth
  • Problems with the cervix, such as a cervix that is weak or short
  • Certain infections, such as bacterial vaginosis or chlamydia
  • Tobacco or alcohol use
  • Taking certain medicines, such as steroids
  • Exposure to pollutants
  • Mental health problems, such as depression or anxiety
  • Problems with the placenta or uterus, such as too much fluid in the womb
  • Vaginal bleeding
  • Birth defects in the fetus


  • American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Obstetrics. Practice Bulletin No. 171: Management of Preterm Labor. Obstet Gynecol. 2016 Oct;128(4):e155-64, reaffirmed 2018.
  • How do health care providers diagnose preterm labor? National Institute of Child Health and Human Development website. Available at: https://www.nichd.nih.gov/health/topics/preterm/conditioninfo/diagnosed.
  • Premature labor. American Pregnancy Association website. Available at: https://americanpregnancy.org/healthy-pregnancy/labor-and-birth/premature-labor.
  • Preterm labor. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/preterm-labor.
  • Preterm labor and birth. The American College of Obstetricians and Gynecologists website. Available at: https://www.acog.org/patient-resources/faqs/labor-delivery-and-postpartum-care/preterm-labor-and-birth.
  • Preterm labor and birth. National Institute of Child Health and Human Development website. Available at: https://www.nichd.nih.gov/health/topics/preterm.


  • Elizabeth Margaret Prusak, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.