[Analysis of clinical effect of cervical cerclage in twin pregnancies with cervical length ≤15 mm at different gestational ages].

Objective: To investigate the clinical effect of cervical cerclage at different gestational weeks in twin pregnancy with cervical length (CL)≤15 mm. Methods: This was a retrospective cohort study. Eighty-three twin pregnant women with CL≤15 mm detected by transvaginal ultrasound at 16-27+6 weeks of gestation in Fujian Maternity and Child Health Hospital from January 2017 to December 2023 were enrolled. According to different treatment methods, they were divided into cervical cerclage group (47 cases) and conservative treatment group (36 cases), and stratified according to the gestational age of CL≤15 mm diagnosis (<26 weeks, ≥26 weeks). The differences in pregnancy outcomes between the two groups were compared. Multivariate logistic regression was used to analyze the effect of cervical cerclage on preterm birth in twin pregnant women with different CL≤15 mm diagnosis weeks. Results: (1) The gestational age at delivery and prolonged gestational age in the cervical cerclage group were longer than those in the conservative treatment group (median gestational age at delivery: 35.3 vs 33.0 weeks; median prolonged gestational age: 10.4 vs 7.2 weeks), and preterm birth rates before 34, 32 and 28 weeks were lower than those in the conservative treatment group [34 weeks: 23% (11/47) vs 53% (19/36); 32 weeks: 15% (7/47) vs 39% (14/36); 28 weeks: 4% (2/47) vs 25% (9/36)], the differences were statistically significant (all P<0.05). There were no significant differences in the rates of preterm birth before 37 weeks of gestation and preterm premature rupture of membranes between the two groups (all P>0.05). (2) When gestational age at CL≤15 mm diagnosis was <26 weeks, pregnancy outcomes in the cervical cerclage group were better than those in the conservative treatment group, including gestational age at delivery (median: 35.4 vs 31.3 weeks) and prolonged gestational age (median: 11.1 vs 5.6 weeks), neonatal birth weight [(2 246±519) vs (1 594±691) g], incidence of adverse neonatal outcomes [19% (13/68) vs 56% (19/34)], and proportion of live births [100% (68/68) vs 82% (28/34)], respectively; the differences were statistically significant (all P<0.05). When the gestational age of CL≤15 mm diagnosis was ≥26 weeks, there were no statistically significant difference in pregnancy outcomes between the two groups (all P>0.05). (3) Multivariate logistic regression analysis showed that when the gestational age of CL≤15 mm diagnosis was <26 weeks, cervical cerclage reduced the risk of preterm birth before 34 weeks (aOR=0.10, 95%CI: 0.02-0.51; P<0.05), 32 weeks (aOR=0.11, 95%CI: 0.02-0.58; P<0.05) and 28 weeks (aOR=0.04, 95%CI: 0.01-0.65; P<0.05). When the gestational age of CL≤15 mm diagnosis was ≥26 weeks, cervical cerclage did not reduce the risk of preterm birth before 34, 32 and 28 weeks of gestation (all P>0.05). Conclusions: Cervical cerclage might reduce the risk of preterm birth and improve neonatal outcomes in twin pregnancies with CL≤15 mm before 26 weeks. However, cerclage showed no advantage over conservative treatment in twin pregnancies with CL≤15 mm over 26 weeks.