LATe Cerclage in High-risk Pregnancies (LATCH)

Inclusion Criteria: * 18-50 years old, pregnant, assigned female at birth * Singleton pregnancy * TVU CL ≤25mm between 24 0/7 - 26 6/7 weeks of gestation Exclusion Criteria: * Initial multifetal gestation with subsequent multifetal pregnancy reduction, or selective fetal termination performed \>14 weeks, or cotwin pregnancy loss diagnosed \>14 weeks * Cerclage in situ * Preterm labor, defined as painful regular uterine contractions and change in cervical dilation * PPROM * Active vaginal bleeding * Suspected intraamniotic infection * Major fetal structural abnormality or chromosomal disorder * Placenta previa or accreta * Other contraindication to cerclage placement * Participation in another clinical trial related to preterm birth prevention, cerclage, or progesterone