Abstract Body

Antiretroviral therapy (ART) is remarkably effective to prevent perinatal transmission (PT) of HIV-1. We sought to evaluate the transmission rate in population in a context of generalized ART before conception.

The analysis included 14,630 HIV-1-infected mothers- delivering from 2000 to 2017 in centers participating in the nationwide prospective multicenter French Perinatal Cohort (ANRS-EPF). PT was analyzed according to time period, timing of ART initiation, plasma viral load (pVL) in the first trimester of pregnancy and at delivery, and gestational age at birth. No woman breastfed in our cohort.

The proportion of women receiving combined ART at delivery increased from 67.7% in 2000-2005 to 97.7% in 2006-2010, and 99.2% in 2011-2017 (p<0.001), as did the proportion of those already on ART before conception (28.3% in 2000-2005 vs 65.8% in 2011-2017, p<0.001) and the proportion of women treated from conception with pVL below limit of quantification (BLOQ) or <50 copies/mL near delivery (70% in 2000-2005, 89% in 2006-2010, 93% in 2011-2017 (p<0.001)). PT decreased from 1.1% in 2000-2005 (58/5,123), to 0.7% in 2006-2010 (30/4600), and 0.2% in 2011-2017 (10/4907; p<0.001). Restricting the analysis to women on ART at conception, PT decreased from 0.42% in 2000-2005 (6/1434), to 0.03% in 2011-2017 (1/3117), p=0.007 (Table). Among women treated at conception, whatever the type of ART combination, no PT was observed if maternal pVL was BLOQ or <50 copies/mL near delivery (0/5482, 95% CI [0-0.07]). In this cohort, there was no case of PT if the 1st trimester viral load was BLOQ or < 50 copies/mL (0/2358), 95%CI [0-0.16]. In the overall population, PT rate was higher following severe preterm deliveries (<32WG) 2.06%, than in moderate preterm (32WG-36WG) 1.34%, or in term deliveries 0.54% (p<0.001). However, this association was not found in 2011-2017, where a higher proportion of women were virally suppressed from the first trimester.

In the absence of breastfeeding, and in the French context of free access to ART and monthly pVL assessment suppressive ART initiated before pregnancy and continued throughout the pregnancy can eliminate perinatal transmission of HIV. The challenge is now to improve early engagement and sustained adherence in health care systems.