Risk factors related to your pregnancy

• Pregnancy with twins, triplets, or more.
• Infection in the urinary or reproductive tract, including the vagina.
• Shortened cervix or incompetent cervix.

Risk factors related to your medical history

• A past preterm delivery.
• Previous surgery on your cervix, such as a cone biopsy. Having a loop electrosurgical excision procedure (LEEP) also may increase preterm labor risk.² But experts don't know for sure if the increased risk is from the surgery itself or the problems with the cervix that led to surgery.³

Other risk factors

• Being younger than 18 years.
• Cigarette smoking during pregnancy.
• Use of cocaine or methamphetamine.

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