Cerclage in twin pregnancy with dilated cervix between 16 to 24 weeks of gestation: retrospective cohort study

BACKGROUND: Cervical dilation in the second trimester is associated with a greater than 90% rate of spontaneous preterm birth and a poor perinatal prognosis. OBJECTIVE: To compare the perinatal outcomes of twin pregnancies with dilated cervix in women who underwent either cerclage or expectant management. STUDY DESIGN: Retrospective cohort study of asymptomatic twin pregnancies identified with cervical dilation of >= 1 cm at 16-24 weeks (1997-2014) at 7 institutions. Exclusion criteria were genetic or major fetal anomaly, multifetal reduction at > 14 weeks, prior cerclage placement, monochorionic-monoamniotic placentation, active vaginal bleeding, labor, chorioamnionitis, elective termination of pregnancy, or medically indicated preterm birth. The primary outcome was incidence of spontaneous preterm birth at < 34 weeks. Secondary outcomes were incidence of spontaneous preterm birth at < 32 weeks, < 28 weeks, and < 24 weeks; perinatal mortality; and composite adverse neonatal outcome (respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and sepsis). RESULTS: A total of 76 women with twin pregnancy with dilated cervix of 1.0-4.5 cm were managed with either cerclage (n = 38) or expectant management (n = 38). Demographic characteristics were not significantly different. Analysis was adjusted for amniocentesis and vaginal progesterone use. In the cerclage group, 29 women (76%) received prophylactic indomethacin and 36 (94%) received prophylactic antibiotics, whereas the expectant management group did not. Interval from time at diagnosis of open cervix to delivery in the cerclage group was 10.46 +/- 5.6 weeks vs 3.7 +/- 3.2 weeks in the expectant management group, with a mean difference of 6.76 weeks (95% confidence interval [CI], 4.71-8.81). There were significant decreases in spontaneous preterm birth at < 34 weeks (52.6% vs 94.7%; adjusted odds ratio [aOR], 0.06; 95% CI, 0.03-0.34), at < 32 weeks (44.7% vs 89.4%; aOR, 0.08; 95% CI, 0.03-0.34); at < 28 weeks (31.6% vs 89.4%; aOR, 0.05; 95% CI, 0.01-0.2); and at < 24 weeks (13.1% vs 47.3%; aOR, 0.17; 95% CI, 0.05-0.54). There were also significant reductions in perinatal mortality (27.6% vs 59.2%; aOR, 0.24; 95% CI, 0.11-0.5), neonatal intensive care unit admission (75.9% vs 97.6%; aOR, 0.07; 95% CI, 0.01-0.66), and composite adverse neonatal outcome (33.9% vs 90.5%; aOR, 0.05; 95% CI, 0.01-0.21). CONCLUSION: Cerclage, indomethacin, and antibiotics in twin pregnancies with dilated cervix >= 1 cm before 24 weeks were associated with significant longer latency period from diagnosis to delivery (6.7 weeks), decreased incidence of spontaneous preterm birth at any given gestational age, and improved perinatal outcome when compared with expectant management.