The primary risk factor for preterm birth is a history of preterm birth. [Institute: 2007] When a woman has a history of preterm birth, she is at risk for preterm birth in any subsequent pregnancy. Many women are unaware of the presence and magnitude of this recurrence risk. The pediatric visit is a unique window of opportunity to counsel women about recurrence risk and preventive strategies.

Preterm birth can also occur spontaneously or as a result of a medical indication for preterm delivery (such as fetal distress or preeclampsia). Depending on the circumstances, the recurrence risk may be 30-50% or higher. It is therefore highly recommended that women consult with a Maternal-Fetal Medicine physician (high-risk obstetrician) before making decisions regarding future pregnancy.

There are 2 primary preventive strategies for preterm birth:

1. Prevent unintended pregnancy
   • Women who do not desire future pregnancy should pursue permanent contraceptive options (e.g., tubal occlusion or vasectomy).
   • Women who desire future pregnancy should have an inter-pregnancy interval of at least 18 months. They should use effective contraception (preferably an intrauterine device (IUD) or contraceptive implant) until they are ready to have another pregnancy.
   • Women without contraception should be referred to a gynecologist or other appropriate health care provider. Subsidized contraception is available through Planned Parenthood (Pregnancy-related, Other [ Discontinued] (see RI providers [0])). Also, see Contraception & Menstrual Management.
2. Prevent or delay preterm birth in a subsequent pregnancy
   • Maternal-Fetal Medicine (high-risk obstetrics) consultation is recommended before the next pregnancy AND early in the next pregnancy.
   • The Maternal-Fetal Medicine physician will discuss strategies to reduce recurrence risk. Depending on the reason for the prior preterm birth, these strategies may include:
     • Quit smoking
     • Stop any illicit drug use
     • Maintain or achieve appropriate weight (normal body mass index)
     • Progesterone supplementation during the next pregnancy
     • Cerclage (‘cervical stitch’) early in the next pregnancy if cervical insufficiency is suspected
     • Optimal medical management of chronic medical problems, such as hypertension, diabetes, and kidney disease