10 A randomized trial of 17-hydroxyprogesterone caproate to prevent preterm birth among women living with HIV

Abstract

Women with HIV face an increased risk of preterm birth (PTB), the leading worldwide cause of child death. 17 alpha-hydroxyprogesterone caproate (17P) has been shown in some trials to reduce early delivery among women with a prior spontaneous PTB. We conducted a randomized, double-masked, placebo-controlled trial of 17P among HIV-infected women attending public-sector antenatal care in Lusaka, Zambia. We excluded women with prior spontaneous PTB or multiple gestation. Participants were randomly allocated to receive weekly intramuscular injections of 250mg 17P or placebo, starting between 16 and 24 gestational weeks and continuing until 36 6/7 weeks, delivery, or stillbirth, whichever occurred first. The trial’s primary outcome was delivery < 37 weeks or stillbirth at any gestational age. We compared the risk of pre-specified outcomes between randomization groups using an intent-to-treat approach. 800 women were randomized between Feb 2018 and Jan 2020. Baseline characteristics were similar between treatment groups. Adherence to study drug was high in both groups (98%) and delivery outcomes were ascertained for all 800 participants. The primary outcome occurred in 36 (9.02%) participants assigned to 17P and 36 (8.98%) assigned to placebo (risk difference = 0.05; 95% CI: -3.92, 4.01). In a pre-specified analysis excluding provider-initiated PTB phenotypes, 25 (6.36%) women randomized to 17P delivered spontaneously before 37 weeks compared to 26 (6.63%) of those receiving placebo (risk difference = -0.27; 95% CI: -3.72, 3.18). The timing of antiretroviral therapy initiation relative to conception did not affect the risk of the primary outcome nor did it modify the effect of the intervention. Related adverse events were low and occurred at similar rates between the study groups. In this trial with complete ascertainment of outcomes and very high adherence to study drug, weekly antenatal 17P injections did not reduce the composite risk of preterm delivery or stillbirth among women with HIV in Zambia.View Large Image Figure ViewerDownload Hi-res image Download (PPT)