The role of prophylactic cerclage in preventing preterm delivery after electrosurgical conization

Abstract

Objective: To evaluate pregnancy outcomes after electrosurgical conization. Methods: We retrospectively analyzed the outcomes of 56 singleton pregnancies after electrosurgical conization of the uterine cervix. Of the 56 cases, 25 women underwent prophylactic cerclage with McDonald procedure (cerclage group), and 31 were managed expectantly (expectant group). Pregnancy outcomes including rate of preterm delivery were compared, and the effect of potential risk factors such as depth of cone, interval between conization and pregnancy, and cervical length on the risk of preterm delivery was assessed. Results: The rate of preterm delivery was significantly higher in women with a history of electrosurgical conization than those without (32.1% vs. 15.2%, p＜0.001). However, preterm delivery rate was not different between the two groups (expectant group vs. cerclage group; ＜28 week, 6.5% vs. 8.0%, p=1.000; ＜34 week, 19.4% vs. 20.0%, p=1.000; ＜37 week, 29.0% vs. 36.0%, p=0.579). All obstetric and neonatal outcomes were similar in the two groups. Even when we confined the study subjects to 19 women (19/56, 33.9%) with cervical length less than 25 mm, the preterm delivery rate also was not significantly different between the expectant (n=7) and cerclage group (n=12). Finally, the potential risk factors for preterm delivery were not associated with risk of preterm delivery in patients with a history of electrosurgical conization. Conclusion:The rate of preterm delivery was significantly higher in women with a history of electrosurgical conization before pregnancy. However, prophylactic cervical cerclage did not prevent preterm delivery in these patients.

Prediction and prevention of preterm birth after cervical conization

“…8 Prophylactic cerclage does not seem to prevent preterm delivery, 9 and even in patients who present with a short cervix, rescue cerclage had failed to show efficacy. 10 Shin et al 5 also failed to see the efficacy of cerclage as a preventive method for preterm birth, even after confining analysis to those with short cervix (cervical length of less than 25 mm). In the study of Nam et al, 4 the rate of preterm birth after cerclage was not lower in patients who had undergone prophylactic cerclage than those without.…”

“…In fact, women who underwent cerclage had significantly shorter cervical length and higher rate of nulliparity, and had lower specimen weight with marginal significance than those in the expectant group. 5 Relatively small number of cases is also the major weak point. Second, both studies did not clarify the urgency of the cerclage.…”

“…But Nam et al 4 tried to focus on the risk factors for preterm birth, and integrated all associated factors together rather than a single factor, in the largest numbers of Korean patients ever published on this subject. The study of Shin et al 5 has the strength that almost all patients were followed up for antenatal care and delivery after conization in a single institution. What issues should be evaluated in further studies?…”

“…However, recent studies with larger sample size, systematic review, or meta-analysis have generally found an increased risk of preterm birth after cold-knife conization and LLETZ or LEEP, although the data on obstetric risk after ablative therapy such as cryotherapy or laser vaporization are contradictory. 2,3 In this issue of Journal of Gynecology Oncology, there are two articles 4,5 dealing with the association between cervical conization and preterm delivery. Both studies showed a higher rate of preterm delivery after cervical conization (27.7% and 32.1%) than that in low risk pregnancies.…”

“…Both studies showed a higher rate of preterm delivery after cervical conization (27.7% and 32.1%) than that in low risk pregnancies. The study of Nam et al 4 focused on the prediction of preterm birth by identifying risk factors, and Shin et al 5 tried to evaluate the efficacy of cerclage as a preventive strategy for preterm birth. In the study of Nam et al, 4 the type of conization, the volume of specimen, and second trimester cervical length were the possible risk factors for preterm birth, but only the second trimester cervical length was the significant risk factor after adjusting for confounding variables in multivariate analysis.…”