Comparison of Pregnancy Outcomes of History-Indicated and Ultrasound-Indicated Cervical Cerclage: A Retrospective Cohort Study

Abstract

Background. Cervical cerclage is the procedure of choice for preventing preterm delivery due to cervical insufficiency. The indication for its application may be based on the woman’s reproductive history, findings at ultrasound, or clinical findings on vaginal examination. Pregnancy outcomes from these indications are variable according to the available literature. Objective. To compare the effectiveness and reproductive outcomes (miscarriage, preterm birth rates, and birth weights) of McDonald’s cervical cerclage after history-indicated and ultrasound-indicated cervical cerclage in pregnant women. Methods. The retrospective cohort study was conducted at Life International Hospital Awka, Nigeria and Life Specialist Hospital Nnewi, Nigeria. Pregnant women, who had a McDonald’s cervical cerclage performed due to either history or ultrasound indication between January 1, 2011, and December 31, 2020, were included in the study. Women with multiple pregnancies and those with physical examination-indicated or emergency cerclages were excluded. The main outcome measures included the prevalence of cervical cerclage, miscarriage, and preterm delivery rates. Outcomes were compared between groups with the chi-square test, Fisher’s exact test, or Student’s $t$ test. $p$ value of < 0.5 was set as significant value. Results. Overall, during the study period, 5392 deliveries occurred in the study sites, of which 103 women had a history-indicated or ultrasound-indicated cervical cerclage. This resulted in a 1.91% prevalence rate for history-indicated and ultrasound-indicated cervical cerclage. Of these, 68 (66%) had history indicated, while 35 (34%) had ultrasound-indicated cerclage. There was no difference in the sociodemographic characteristics of both groups. Both groups had similar miscarriage rates: 1.18 in 1000 and 1.04 in 1000 deliveries, respectively (RR 1.160, 95% CI: 0.3824 to 3.5186, $p=0.793$ ). There was more preterm delivery in history-indicated cerclage than ultrasound-indicated cervical cerclage (26.50% vs. 17.10%; $p=0.292$ ), though the difference was not statistically significant. The ultrasound group had a higher average birthweight than the history group ( $2.67\pm 0.99$ vs. $2.53\pm 0.74$ ). However, this difference was not statistically significant. Conclusion. The effectiveness and reproductive outcomes (miscarriage, preterm birth rates, and birth weights) of pregnant women with cervical cerclage due to history-indicated and ultrasound-indicated cervical cerclage appear similar. When needed, cervical cerclage should be freely applied for cervical insufficiency, irrespective of the type of indication.