Intrapartum Sildenafil to Improve Perinatal Outcomes: A Randomized Clinical Trial.

Area of Science:

• Obstetrics and Gynecology
• Neonatal Medicine
• Pharmacology

Background:

• Intrapartum fetal hypoxia, caused by reduced placental perfusion during labor, risks stillbirth and neonatal encephalopathy.
• Current monitoring methods haven't improved outcomes, necessitating novel strategies to prevent hypoxic injury.
• Phosphodiesterase type 5 inhibitors like sildenafil citrate may enhance uteroplacental perfusion.

Purpose of the Study:

• To evaluate if oral sildenafil citrate administered during labor improves perinatal outcomes in infants at risk of intrapartum hypoxia.
• To assess the efficacy of sildenafil citrate in reducing the incidence of adverse perinatal events and operative births due to fetal distress.

Main Methods:

• The iSEARCH trial was a placebo-controlled, double-blind randomized clinical trial involving 3257 women across 14 Australian hospitals.
• Participants received either 50 mg sildenafil citrate or placebo every 8 hours for a maximum of 3 doses during labor.
• The primary outcome was a composite of 10 intrapartum or neonatal complications; secondary outcomes included individual components and emergency operative births.

Main Results:

• The primary composite outcome occurred in 5.1% of the sildenafil group versus 5.2% in the placebo group (RR, 1.02; 95% CI, 0.75-1.37).
• No significant differences were observed in individual secondary outcomes, including emergency cesarean or instrumental vaginal birth for fetal distress (RR, 1.12; 95% CI, 0.98-1.29).
• No infant deaths were reported in either group.

Conclusions:

• Oral sildenafil citrate administered during labor did not demonstrate a significant benefit in reducing adverse perinatal outcomes or the need for emergency operative birth for fetal distress.
• The findings suggest that sildenafil citrate is not effective for preventing intrapartum hypoxia-related complications in this study population.
• Further research may be needed to explore alternative interventions for improving fetal well-being during labor.