Uterine atony

Risk of Uterine Atony After Vaginal, Cesarean Delivery

A risk-prediction model may identify women at risk of uterine atony after vaginal and cesarean delivery and may reduce the risk of postpartum hemorrhage and morbidity.

Researchers used retrospective data from deliveries at a single medical center between 2010 and 2019 to develop both intrapartum and antepartum risk-prediction models based on prespecified risk factors identified from a systematic review. They used logistic regression and stipulated that uterine atony was indicated by the supplementary administration of a uterotonic along with the prophylactic infusion of oxytocin. To validate their models, they then used the C‑statistic to measure the ability of each model to discriminate between cases and controls.

Data were obtained for 4773 cases of uterine atony and 23,933 controls. The antepartum model included 20 risk factors. Moderate discriminatory ability was observed in the antepartum model (C‑statistic 0.61; 95% CI; 0.60 - 0.62). The intrapartum model included 27 risk factors. This model had a better ability to discriminate than the antepartum model (C-statistic 0.68; 95% CI; 0.67 - 0.69).

“Models performed similarly for all delivery modes, races, and ethnic groups. Future work should further improve these models through inclusion of more  comprehensive prediction data,” researchers concluded.


—Ellen Kurek



Ende HB, French B, Shi Y, Kertai MD, Osmundson SS, Bauchat JR. Development of clinical risk-prediction models for uterine atony following vaginal and cesarean delivery. Int J Obstet Anesthesia. Published online April 21, 2022. doi:10.1016/j.ijoa.2022.103550