(491) Can pre-cesarean angle of progression predict maternal complications in second-stage labor arrest?

Objective: An emergency cesarean delivery (CD) performed during the second stage of labor can be associated with increased maternal complications, as a low fetal head in the maternal pelvis can be associated with a challenging fetal extraction. The angle of progression (AOP) is an objective sonographic tool to monitor fetal head descent, and an AOP of 116º was described as equivalent to fetal head at station “0”. This study aimed to assess the association between the AOP at rest as measured before the decision of an emergency CD due to arrest of descent during the second stage of labor and the rates of intraoperative and postoperative maternal complications.

Study Design: This retrospective study included all primiparous women who underwent an emergency CD due to arrest of descent during the second stage of labor and had an AOP recorded in the electronic medical charts between January 2017 and May 2023. The cohort was divided into two groups based on the AOP measurement at rest before the decision on a CD: 1. AOP≤116º and 2. AOP >116º. The maternal intraoperative and postoperative complication rates were compared between the two groups.

Results: The demographic characteristics were comparable between women with an AOP≤116º (n=41) and those with an AOP >116º (n=127) (Table 1). Women with an AOP >116º had a significantly higher composite intraoperative complications rate than those with an AOP≤116º (47% vs. 29%, p=0.04), mostly attributed to increased rates of uterine extensions and difficult extractions. No significant differences were noted in the total maternal postoperative complications rate (29% vs. 29%, p=0.93) and short-term neonatal outcomes (Table 1).

Conclusion:

Among primiparous women who underwent an emergency cesarean delivery due to arrest of descent during the second stage of labor, those with an AOP greater than 116º as assessed by trans-perineal ultrasound had a higher rate of a composite of intraoperative complications. This finding highlights the importance of adequately preparing for emergency cesarean sections (e.g., fetal head pushing from the vagina or breach extraction) in these women.