Pregnancy outcomes in women treated with elective versus ultrasound-indicated cervical cerclage

Abstract

Objective: To compare pregnancy outcomes in women at risk for pregnancy loss treated with elective versus ultrasound-indicated placement of cerclage.

Methods: A retrospective cohort study was performed on two groups of patients with singleton gestations. The first group consisted of women at risk for pregnancy loss who were treated with an elective cerclage, while the second group was managed conservatively and followed with serial transvaginal cervical sonography and transfundal pressure. An emergency cerclage was placed in women in the second group when the endocervical canal length shortened to < 20 mm, either spontaneously or in response to transfundal pressure. The two groups were compared with respect to maternal demographics, obstetric and gynecological history, and gestational age, both at time of cerclage placement and delivery.

Results: A total of 138 patients were identified. Eighty-one patients were treated with an elective cerclage and 57 with an ultrasound-indicated cerclage. Patients treated with elective cerclages were older (32 versus 27 years, p = 0.0003), more commonly white (56.8% versus 38.6%, p = 0.0380), less commonly nulliparous (23.5% versus 43.9%, p = 0.0063), and more often private patients (92.6% versus 28.1%, p < 0.0001). A history of previous treatment with cerclage (45.7% versus 10.5%, odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1-0.4) and one prior midtrimester loss (53.1% versus 33.3%, OR 0.4, 95% CI 0.2-0.9) were also more common in the elective versus ultrasound-indicated cerclage group. However, there was no difference in the rates of previous preterm delivery, two midtrimester losses, two terminations of pregnancy, in utero diethylstilbestrol exposure, uterine anomalies, history of cone biopsy or parity. As expected, gestational age at placement of cerclage was significantly earlier in the elective group (13.0 versus 20.0 weeks, p < 0.0001). The median (range) gestational age at delivery (37 (15-41) versus 37 (17-41) weeks, p = 0.90), the number of early (< 25 weeks) losses (9.9% versus 8.8%, OR 1.6, 95% CI 0.3-7.9), and preterm deliveries (< 37 weeks) (35.8% versus 36.8%, OR 1.1, 95% CI 0.4-3.2) were similar in the elective and ultrasound-indicated cerclage patients, respectively.

Conclusion: In patients at risk for pregnancy loss, placement of cervical cerclages in response to ultrasonographically detected shortening of the endocervical canal length is a medically acceptable alternative to the use of elective cerclage.