Prevention of preterm delivery by 17 alpha-hydroxyprogesterone caproate in asymptomatic twin pregnancies with a short cervix: a randomized controlled trial

OBJECTIVE: The objective of the study was to evaluate the use of 17 alpha-hydroxyprogesterone caproate (17P) to reduce preterm delivery in women with a twin pregnancy and short cervix. STUDY DESIGN: This open-label, multicenter, randomized controlled trial included women with a twin pregnancy between 24(+0) and 31(+6) weeks of gestation who were asymptomatic and had a cervical length of 25 mm or less measured by routine transvaginal ultrasound. Women were randomized to receive (or not) 500 mg of intramuscular 17P, repeated twice weekly until 36 weeks or preterm delivery. The primary outcome was time from randomization to delivery. Analysis was performed according to the intent-to-treat principle. RESULTS: The 17P and control groups did not differ significantly for median [interquartile range] time to delivery: 45 (26-62) and 51 (36-66) days, respectively. However, treatment with 17P was associated with a significant increase in the rate of preterm delivery before 32 weeks. CONCLUSION: Twice-weekly injections of 17P did not prolong pregnancy significantly in asymptomatic women with a twin pregnancy and short cervix.