Interim analysis showed no difference in outcome between treatment groups.

We hypothesized that weekly intramuscular injections of 17 hydroxyprogesterone caproate(17P) will reduce the number spontaneous preterm births prior to 35 weeks gestation when compared to cerclage therapy. The purpose of this study was to compare medical therapy with 17P to surgical therapy with transvaginal cerclage in patients with an ultrasound diagnosed short cervix and funnel in the mid-trimester.

Inclusion Criteria:

• Ultrasonographic evidence of premature dilatation of the internal os
• Prolapse of the chorio-amniotic membranes into the endocervical canal
• Functional cervical length less than 25mm
• Exacerbation of these ultrasound findings with transfundal and/or suprapubic pressure

Exclusion Criteria:

• Any fetal chromosomal or structural anomaly
• Multiple gestation
• Known allergy to progesterone
• Ruptured membranes
• Vaginal bleeding
• Intra-amniotic infection (diagnosed clinically or by amniocentesis)
• Prolapse of endocervical membranes beyond the external cervical os
• Persistent uterine activity accompanied by cervical change
• Obstetrically indicated delivery.