RCT of Progesterone to Prevent Preterm Birth in Nulliparous Women With a Short Cervix

A Randomized Trial of 17 Alpha-Hydroxyprogesterone Caproate for Prevention of Preterm Birth in Nulliparous Women With a Short Cervix

The purpose of this study is to see if giving progesterone medication to pregnant women, who have never delivered a baby after 19 weeks of pregnancy and who have a short cervix, lowers the risk of early delivery and improves the health of their baby.

Preterm births, defined as the delivery of a baby less than 37 weeks of gestation, are responsible for the majority of neonatal mortality and morbidities. Studies have shown that a number of risk factors, including never having a baby before and having a short cervix are associated with early delivery. Recently the NICHD did a study in women who were pregnant again after having delivered preterm. It showed that giving 17 alpha-hydroxyprogesterone caproate (17P) medication during pregnancy decreased the chance of delivering another preterm baby by 34%. This placebo-controlled randomized clinical trial will address the primary research question: does treatment with 17P initiated before 23 weeks of gestation prevent delivery prior to 37 weeks in nulliparous women with a singleton gestation who have a short cervix?

Inclusion Criteria:

• Nulliparous
• Cervical length as measured on transvaginal examination < 30mm between gestational ages of 16 weeks 0 days to 22 weeks 3 days
• Gestational age 16 weeks 3 days to 22 weeks 6 days at time of randomization

Exclusion Criteria:

• Multifetal gestation
• Progesterone treatment after 14 weeks 6 days during current pregnancy
• Vaginal bleeding, heavier than spotting, after 15 weeks 6 days
• Amniotic membranes prolapsed beyond external os
• Preterm rupture of membranes
• Fetal anomaly
• Pregnancy without a viable fetus
• Current or planned cervical cerclage
• Congenital Mullerian abnormality of the uterus
• Contraindication to intra-muscular injections
• Hypertension requiring medication
• Diabetes managed with insulin or oral hypoglycemic agents
• DES exposure
• Cervical surgery such as cold knife conization
• Planned indicated preterm delivery
• Participation in another interventional study that influences age at delivery
• Participation in this trial in a previous pregnancy
• Prenatal care or delivery planned outside a MFMU Network center