Publications

Background: The use of azithromycin reduces maternal infection in women during unplanned cesarean delivery, but its effect on those with planned vaginal delivery is unknown. Data are needed on whether an intrapartum oral dose of azithromycin would reduce maternal and offspring sepsis or death.

Methods: In this multicountry, placebo-controlled, randomized trial, we assigned women who were in labor at 28 weeks' gestation or more and who were planning a vaginal delivery to receive a single 2-g oral dose of azithromycin or placebo. The two primary outcomes were a composite of maternal sepsis or death and a composite of stillbirth or neonatal death or sepsis. During an interim analysis, the data and safety monitoring committee recommended stopping the trial for maternal benefit.

Results: A total of 29,278 women underwent randomization. The incidence of maternal sepsis or death was lower in the azithromycin group than in the placebo group (1.6% vs. 2.4%), with a relative risk of 0.67 (95% confidence interval [CI], 0.56 to 0.79; P<0.001), but the incidence of stillbirth or neonatal death or sepsis was similar (10.5% vs. 10.3%), with a relative risk of 1.02 (95% CI, 0.95 to 1.09; P = 0.56). The difference in the maternal primary outcome appeared to be driven mainly by the incidence of sepsis (1.5% in the azithromycin group and 2.3% in the placebo group), with a relative risk of 0.65 (95% CI, 0.55 to 0.77); the incidence of death from any cause was 0.1% in the two groups (relative risk, 1.23; 95% CI, 0.51 to 2.97). Neonatal sepsis occurred in 9.8% and 9.6% of the infants, respectively (relative risk, 1.03; 95% CI, 0.96 to 1.10). The incidence of stillbirth was 0.4% in the two groups (relative risk, 1.06; 95% CI, 0.74 to 1.53); neonatal death within 4 weeks after birth occurred in 1.5% in both groups (relative risk, 1.03; 95% CI, 0.86 to 1.24). Azithromycin was not associated with a higher incidence in adverse events.

Conclusions: Among women planning a vaginal delivery, a single oral dose of azithromycin resulted in a significantly lower risk of maternal sepsis or death than placebo but had little effect on newborn sepsis or death. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; A-PLUS ClinicalTrials.gov number, NCT03871491.)

BACKGROUND: In 2023, the Azithromycin Prevention in Labor Use (A-PLUS) trial showed intrapartum azithromycin reduces maternal sepsis or death in women with planned vaginal delivery in low-resource settings, but whether it reduces maternal infection is unknown. We aimed to evaluate the effectiveness of intrapartum azithromycin in reducing maternal infection. METHODS: We performed a post-hoc analysis of the multicentre, facility-based, randomised, double-blind, placebo-controlled A-PLUS trial. This trial compared prophylactic intrapartum single oral dose of 2 g azithromycin versus placebo on maternal morbidity and mortality in low-resource settings in southeast Asia and Africa from Sept 9, 2020, to Aug 18, 2022. The trial enrolled women in labour at 28 weeks' gestation (or later) at eight sites in the Democratic Republic of the Congo, Kenya, Zambia, Bangladesh, India, Pakistan, and Guatemala and found that azithromycin reduced the incidence of maternal sepsis or death. The primary outcome of the present analysis was the incidence of any maternal infection in the azithromycin versus placebo groups, which was defined as one or more of these infections after randomisation: chorioamnionitis, endometritis, perineal or caesarean wound infection, abdominopelvic abscess, mastitis or breast abscess, and other infections. Any neonatal infection was also analysed. All analyses were by intention to treat in all those with data available for that outcome. Relative risks (RRs) and 95% CIs were estimated with a Poisson model adjusted for treatment group and site. Subgroup analyses included a two-way interaction test between intervention group and subgroup. A-PLUS was registered at ClinicalTrials.gov, number NCT03871491. FINDINGS: 29 278 women were randomly assigned to groups: 14 590 to receive azithromycin, 14 688 to receive placebo. Baseline characteristics were similar between the azithromycin and placebo groups (43·3% vs 43·4% primiparous, 8·5% vs 8·7% high risk for infection). The presence of any maternal infection occurred less often in the azithromycin group (580 [4·0%] of 14 558) compared with the placebo group (824 [5·6%] of 14 661 women; RR 0·71, 95% CI 0·64-0·79, p<0·0001). Any neonatal infection did not differ between treatment groups. Adverse events were not detected. INTERPRETATION: Among women planning vaginal delivery, this analysis provides evidence indicating that intrapartum azithromycin is associated with a lower incidence of maternal infections than placebo. FUNDING: The Eunice Kennedy Shriver National Institute of Child Health and Human Development and Bill and Melinda Gates Foundation via Foundation of National Institutes of Health. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.