Cerclage Location and Gestational Age at Delivery

Area of Science:

• Maternal-Fetal Medicine
• Obstetrics
• Reproductive Science

Background:

• Cervical length (CL) and cerclage placement are critical in managing cervical insufficiency.
• The precise position of the cerclage stitch (cerH, PRL) may influence pregnancy outcomes.
• Previous studies suggest cerclage position impacts success, but evidence is varied.

Purpose of the Study:

• To assess the interaction between cervical length, cerclage height, and proximal residual length on gestational age at delivery.
• To determine if cerclage position predicts delivery before 34 weeks.
• To analyze these relationships based on cerclage indication: history (Hx), physical exam (PE), or ultrasound (US).

Main Methods:

• Retrospective cohort study of cerclages placed between 2006-2016.
• General linear models used to predict gestational age at delivery based on cerH, CL, and indication.
• Logistic regression analyzed the rate of delivery before 34 weeks.

Main Results:

• Cerclage height by indication did not reach statistical significance overall (p=0.090).
• Stratified analysis revealed cerclage height significantly impacted gestational age for Hx (adjusted R²=0.18, p<0.001) and PE (adjusted R²=0.43, p=0.004) indicated cerclages.
• No significant effect of cerclage height was found for US-indicated cerclages (adjusted R²=0.08, p=0.206).

Conclusions:

• Cerclage stitch height is a significant predictor of gestational age at delivery for history and physical exam indicated cerclages.
• Higher cerclage placement is associated with more advanced gestational age at delivery in these specific indications.
• The findings suggest optimizing cerclage placement may improve pregnancy outcomes in select cases of cervical insufficiency.