Propranolol fails to Reduce Cesarean Delivery Rates In Prolonged Labor

Prolonged labor can be a challenging situation for both mothers and healthcare providers. To explore potential interventions for managing prolonged labor, a recent double-blind, placebo-controlled, randomized trial evaluated the effects of intravenous (IV) propranolol on cesarean delivery rates in these patients. Propranolol is a β-blocker commonly used to treat conditions such as hypertension and anxiety. The recent study published in the journal of Obstetrics And Gynaecology aimed to determine whether propranolol administration could reduce the need for cesarean delivery in women experiencing prolonged labor.

A recent double-blind, placebo-controlled, randomized trial was conducted by McCoy Jenniffer A. and colleagues at two hospitals within a large academic health system, the trial included eligible patients who were at 36 weeks or more of gestation with a singleton pregnancy and prolonged labor. Prolonged labor was defined as either a prolonged latent phase (dilation less than 6 cm after 8 hours or more with ruptured membranes and receiving oxytocin infusion) or a prolonged active phase (dilation 6 cm or greater and less than 1-cm cervical dilation change over 2 hours or more with ruptured membranes and receiving oxytocin infusion). Patients with certain conditions, such as severe preeclampsia or cardiac contraindications to β-blockade, were excluded from the study.

The participants were randomized to receive either propranolol (2 mg IV) or a placebo (2 mL normal saline IV), with a possible repeat dose. The primary outcome measured was the rate of cesarean delivery. Secondary outcomes included labor duration, shoulder dystocia, and maternal and neonatal morbidity. The trial aimed to enroll 326 patients to detect a 15% reduction in the cesarean delivery rate with 80% power. However, a planned interim analysis was performed, and the trial was stopped for futility.

● The results revealed that out of the 164 enrolled and randomized patients, there was no significant difference in the rate of cesarean delivery between the propranolol group and the placebo group.

● The cesarean delivery rates were 57.1% in the propranolol group and 57.5% in the placebo group, indicating comparable rates (relative risk [RR] 0.99, 95% CI 0.76–1.29).

● The findings remained consistent when analyzing subgroups based on the phases of labor (prolonged latent and active) and the parity status of the patients (nulliparous and multiparous).

● Although not statistically significant, the frequency of postpartum haemorrhage was higher in the propranolol group compared to the placebo group (20% vs. 10%, RR 2.02, 95% CI 0.93–4.43).

The study's results indicate that IV propranolol administration did not lead to a reduction in cesarean delivery rates among women experiencing prolonged labor. These findings suggest that propranolol may not be an effective intervention for managing prolonged labor and avoiding cesarean deliveries in these cases.

It is important to note that this study provides valuable insights into the potential role of propranolol in the management of prolonged labor, but it also has limitations. The trial was

stopped early due to futility, which means that the planned sample size was not reached, and the study might have been underpowered to detect smaller but clinically relevant differences. Additionally, the study observed a higher frequency of postpartum haemorrhage in the propranolol group, although the difference was not statistically significant. Further research is necessary to explore this potential association and determine the safety profile of propranolol in the context of prolonged labor.

A recent double-blind, placebo-controlled, randomized trial investigating the effects of IV propranolol in patients with prolonged labor found no significant difference in cesarean delivery rates compared to the placebo group. The study suggests that propranolol may not be an effective intervention for reducing the need for cesarean deliveries in cases of prolonged labor. These findings contribute to the ongoing exploration of treatment options for managing prolonged labor, emphasizing the need for further research to identify alternative strategies that could improve outcomes for both mothers and infants in this context.

Reference:

McCoy, J. A., Walheim, L., McCabe, M. G., & Levine, L. D. (2023). Efficacy of propranolol to reduce cesarean delivery in prolonged labor: A randomized controlled trial. Obstetrics and Gynecology, 10.1097/AOG.0000000000005232.