Presentations

Abstract

Introduction: 

Preterm delivery occurs in approximately 10% of live births in the United States. Preterm birth is the leading cause of neonatal death and chronic neurological complications for pre-term infants. A history of cervical insufficiency in a current or previous pregnancy is one of the largest risk factors for pre-term delivery. This study evaluated pregnancy outcomes of history-indicated cerclage compared with ultrasound cervical length screening in patients with a history of cervical insufficiency defined as prior spontaneous preterm delivery from 14 0/7 to 23 6/7 weeks' of gestation.

Methods: 

This was a retrospective cohort study of patients with singleton gestations with a history of cervical insufficiency. Patients who started prenatal care after 24 weeks, delivered before 24 weeks, or declined a history-indicated cerclage or cervical length screening were excluded. The primary outcome was preterm delivery <37 weeks gestation. Secondary outcomes included gestational age at delivery, spontaneous preterm birth <37 weeks, spontaneous preterm birth <34 weeks, preterm premature rupture of membranes, cesarean delivery, birthweight, and neonatal intensive care (NICU) admissions. Adjusted odds ratios (aOR) with 95th confidence intervals (95%CI) were calculated, controlling for confounders.

Results:

Of 376 pregnancies 177 (47.1%) patients underwent history-indicated cerclage, and 199 (52.9%) underwent cervical length screening. Of 199 who underwent cervical length screening, 92 (46%) underwent ultrasound-indicated or physical exam-indicated cerclage. Compared to cervical length screening, history-indicated cerclage was not associated with increased odds of preterm delivery less than 37 weeks (37.7% vs. 29.4%; aOR 0.75 [95%CI 0.48-1.18]). However, compared to cervical length screening, history-indicated cerclage was associated with decreased odds of spontaneous preterm delivery less than 34 weeks (18.1% vs. 9.0%; aOR 0.47 [95%CI 0.23-0.97]).

Conclusions:

History-indicated cerclage compared with cervical length screening was associated with decreased odds of spontaneous preterm delivery less than 34 weeks. Given that approximately half of the patients undergoing cervical length screening required cerclage, history-indicated cerclage should be considered for patients with a history of cervical insufficiency. However, when it came to deliveries between 34 and 37 weeks, there were no major differences between pregnancies monitored with transvaginal ultrasound and patients who received cerclage for cervical insufficiency.