(124) Effect of Hygroscopic Osmotic Dilator versus Foley Balloon on Cesarean Delivery Rates: A Bayesian Analysis

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: To test the hypothesis that Dilapan-S is superior to the Foley balloon for pre-induction cervical ripening at term using a Bayesian analysis.

Study Design: Secondary analysis of a single-center randomized clinical trial (DILAFOL) comparing Dilapan-S to the Foley balloon for pre-induction cervical ripening at term. The primary analysis, which was by a non-inferiority approach, showed that Dilapan-S was non-inferior to Foley but was associated with better patient satisfaction. Using a neutral prior distribution, we calculated the Bayesian probability that the cesarean rate in the Dilapan-S group is not higher by more than ten percentage points (non-inferior margin), not higher by more than five percentage points, and lower by any percentage point (superiority) compared with the rate in the Foley group. Intent to treat (ITT) and per-protocol (PP) analyses were performed.

Results:

The trial enrolled 417 subjects. In the ITT analysis, the probability that the risk difference would be less than 10, 5, and 0 percentage points were 0.99, 0.99, and 0.89, respectively. The Bayesian mean risk difference estimate was -5.0 (95% credible interval −12.8 to 2.7, Table). Similar results were noted when performing the analysis on the PP population (Table). The probability that the risk difference would be less than 0 percentage points was 0.92, and the Bayesian mean estimate of the risk difference was -5.8 (95% credible interval −13.7 to 2.1, Table).

Conclusion: Dilapan-S has a high probability of decreasing cesarean rates in patients undergoing pre-induction cervical ripening compared with Foley balloon. Depending on price differences, the savings from lower cesarean and improved patient satisfaction may make Dilapan-S a suitable alternative to Foley.

Primary & Presenting Author(s)

Antonio F. Saad, MD
Associate Professor in Maternal Fetal Medicine and Critical Care
University of Texas Medical Branch
Galveston, Texas, United States

Coauthor(s)

CP
Claudia Pedroza, PhD
McGovern Medical School, University of Texas Health Science Center at Houston
Houston, Texas, United States
George R. Saade, MD
Professor & Chief of Obstetrics & Maternal-Fetal Medicine
University of Texas Medical Branch
Galveston, Texas, United States