Cerclage On LOw Risk Singletons: Cervical Cerclage for Prevention of Spontaneous Preterm Birth in Low Risk Singleton Pregnancies With Short Cervix

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