Prevention of Preterm Birth

Risk-Based Strategies

The American College of Obstetricians and Gynecologists recommends 17-alpha-hydroxyprogesterone caproate (17P) 250 mg intramuscularly weekly for women with a history of spontaneous preterm birth between 20-36 6/7 weeks of gestation 1, 2, 3
For women with a singleton pregnancy, no history of preterm birth, and a short cervix (≤20 mm at 24 weeks), vaginal progesterone (90 mg gel or 200 mg suppository) is recommended 1, 2, 3
This treatment reduces preterm birth and perinatal morbidity and mortality 1, 2

The American College of Obstetricians and Gynecologists suggests that history-indicated cerclage is only recommended for women with classic cervical insufficiency characteristics or unexplained second-trimester loss, in the absence of placental abruption 4, 5
Transvaginal cervical length measurements should start between 16-24 weeks of gestation 4

Progesterones (both vaginal and 17P) are not effective in preventing preterm birth in multiple pregnancies 1, 2, 3
Routine hospitalization and activity restriction are not recommended for preventing preterm birth in multiple pregnancies (Grade 1A recommendation) 6, 7

Routine use of any type of activity restriction is not recommended for women at risk of preterm birth, regardless of symptoms of preterm labor, arrested preterm labor, or short cervix (Grade 1B recommendation) 6, 7
Activity restriction does not improve perinatal outcomes and may increase the risk of preterm birth 6, 7

Women with a history of preterm premature rupture of membranes (PPROM) are at high risk of recurrent preterm birth, with nearly 50% of subsequent pregnancies resulting in preterm birth, 30% <34 weeks, 23% <28 weeks, and 17% <24 weeks 4, 5