Transabdominal cerclage: can we predict who fails?

OBJECTIVE

To examine the outcome of pregnancies in women with transabdominal cerclage (TAC) and to determine whether aspects of the obstetric history predict failure.

METHODS

This was a cohort study of pregnant women referred for a transabdominal cerclage between 1978 and 2004. Records were reviewed for obstetric history and maternal demographics. Predictor variables were prior pregnancy loss, prior vaginal cerclage, associated factors for TAC, and maternal age. The outcome variable was delivery of an infant beyond 24 weeks who survived the neonatal period. Outcomes were compared using Student's t-test, standard z-test, and Chi-square test.

RESULTS

Eighty-eight women delivered 96 pregnancies after TAC placement. The fetal salvage rate prior to TAC was 18%, 93% after the procedure (p<0.001). Delivery beyond 37 weeks occurred in 70% of pregnancies. Maternal age, prior cerclage history, associated factors for TAC, or previous delivery of a viable infant did not predict the eight failures out of the 96 pregnancies.

CONCLUSION

Women with TAC had a higher rate of successful pregnancies than prior to TAC. Neither maternal age nor prior pregnancy loss predicted failure. However with such a high success rate, we would have needed 948 women to do so. TAC is an option for women with a poor obstetric history including failed vaginal cerclage.