The aim of this study is to evaluate the efficacy of cervical cerclage in prevention of spontaneous preterm birth in singleton pregnancies with a short transvaginal cervical length (<=25mm) and without prior spontaneous preterm birth

Singleton pregnancies between 18 0/7 to 23 6/7 weeks without a prior spontaneous preterm birth found to have a short transvaginal ultrasound cervical length (<=25mm) and meeting all other eligibility criteria will be randomized to either cervical cerclage or control (no cerclage). Aside from cerclage placement, management of included women will be the same including recommendation for daily vaginal progesterone 200mg suppository or 90mg gel from randomization until 36 6/7 weeks. The primary outcome will be the incidence of spontaneous preterm birth <35 weeks

Inclusion Criteria:

• 18 year old or older
• Singleton pregnancy
• No prior SPTB or second trimester losses between 160 and 366 weeks
• TVU CL ≤25mm between 180 and 236 weeks

Exclusion Criteria:

• Multiple pregnancy
• Prior SPTB or second trimester losses between 160 and 366 weeks
• Cerclage in situ
• Painful regular uterine contraction and/or preterm labor
• Rupture membranes
• Major fetal anomaly or aneuploidy
• Active vaginal bleeding
• Placenta previa and/or accreta
• Cervical dilation >1.0 cm and/or visible membranes by pelvic exam
• Suspicion of chorioamnionitis

Patients must be pregnant to be enrolled. Self-represented gender identity is NOT a basis of eligibility

IPD will be shared upon completion of appropriate data sharing agreements

1yr after study completion

IPD will be shared upon completion of appropriate data sharing agreements