Azithromycin-Prevention in Labor Use Study (A-PLUS)

The A-PLUS Trial is a randomized, placebo-controlled, parallel multicenter clinical trial. The study intervention is a single, prophylactic intrapartum oral dose of 2 g azithromycin, with a comparison with a single intrapartum oral dose of an identical appearing placebo. For the A-PLUS randomized control trial (RCT), a total of 34,000 laboring women from eight research sites in sub-Saharan Africa, South Asia, and Latin America will be randomized with one-to-one ratio to intervention/placebo. In response to the global coronavirus pandemic, research sites will also collect data on COVID-19 signs/symptoms, diagnosis, and treatment in order to estimate the incidence of infection and evaluate the impact of the pandemic on the target population.

Prior to the initiation of the A-PLUS RCT, research sites will conduct an observational pilot study using the RCT's planned infrastructure in order to characterize the current practices at participating research facilities and optimize the identification of suspected infection for the RCT. The information obtained in the pilot study will be used to validate estimates of intrapartum deaths, maternal sepsis, and neonatal sepsis used in the sample size calculations for the RCT. Finally, the pilot study will allow the research sites to inventory and upgrade local capacity to conduct routine cultures during the RCT.

A maximum of 16,000 women, separate from the sample for the main trial, will be enrolled in the pilot, across all eight research sites, with no more than 2000 women enrolled at any individual site. Research sites will be eligible to transition to the RCT when a minimum of 600 participants have been enrolled in the pilot study with evidence of (a) high rates of follow-up; (2) acceptable data quality and completeness; and (3) there are no concerns about identification and reporting of infection.

Given the clinical benefits of intrapartum azithromycin so far reported in two trials and the likelihood that it may become the usual practice if the investigator's large RCT confirms the reported benefits, it is important to monitor antibiotic resistance to determine the safety of azithromycin prophylaxis. Therefore, the RCT will also include an ancillary study (referred to as the antimicrobial resistance (AMR) sub-study) to monitor antimicrobial resistance and maternal and newborn microbiome effects of the single dose of prophylactic azithromycin using the following methodology

• For all mothers enrolled in the RCT and their infants:

a. Routine clinical monitoring at baseline and three post-partum time points (3 days, 7 days, and 42 days), with culture and sensitivity testing in cases of suspected bacterial infections;

• Among a subset of 1000 randomly selected maternal-infant dyads:

• Serial susceptibility monitoring of antimicrobial resistance patterns (including azithromycin resistance) from selected maternal and newborn flora through culture and sensitivity testing. Serial monitoring will be conducted at baseline and three post-partum time points (1 week, 6 weeks, and 3 months).
• Serial microbiome collection and storage of specimens for future testing to monitor maternal and newborn microbiome status of selected sites.

Inclusion criteria

• Pregnant women in labor ≥28 weeks Gestational Age (GA) (by best estimate) with a pregnancy with one or more live fetuses who plan to deliver vaginally in a facility.
• Admitted to health facility with clear plan for spontaneous or induced delivery.
• Live fetus must be confirmed via a fetal heart rate by Doptone prior to randomization.
• ≥18 years of age or minors 14-17 years of age in countries where married or pregnant minors (or their authorized representatives) are legally permitted to give consent.
• Have provided written informed consent.
• Pregnant women in labor ≥28 weeks GA (by best estimate) with a pregnancy with one or more live fetuses who plan to deliver vaginally in a facility.
• Admitted to health facility with clear plan for spontaneous or induced delivery.
• Live fetus must be confirmed via presence of a fetal heart rate prior to randomization.
• ≥18 years of age or minors 14-17 years of age in countries where married or pregnant minors (or their authorized representatives) are legally permitted to give consent.
• Have provided written informed consent [Note: written informed consent may be obtained during antenatal care, but verbal re-confirmation may be needed (per local regulations) at the time of randomization].

Exclusion criteria

• Non-emancipated minors (as per local regulations)
• Evidence of chorioamnionitis or other infection requiring antibiotic therapy at time of eligibility (however, women given single prophylactic antibiotics with no plans to continue after delivery should not be excluded).
• Arrhythmia or known history of cardiomyopathy.
• Allergy to azithromycin or other macrolides that is self-reported or documented in the medical record.
• Any use of azithromycin, erythromycin, or other macrolide in the 3 days or less prior to randomization.
• Plan for cesarean delivery prior to randomization.
• Preterm labor undergoing management with no immediate plan to proceed to delivery.
• Advanced stage of labor (>6 cm or 10 cm cervical dilation per local standards) and pushing or too distressed to understand, confirm, or give informed consent regardless of cervical dilation.
• Are not capable of giving consent due to other health problems such as obstetric emergencies (for example, antepartum hemorrhage) or mental disorder.
• Any other medical conditions that may be considered a contraindication per the judgment of the site investigator.
• Previous randomization in the trial.