by Carolyn Chu, MD, MSc, AAHIVS, AAHIVM Chief Medical Officer
September 13, 2022
French Perinatal Cohort (ANRS C01/C011) collaborators sought to revisit perinatal HIV-1 transmission rate estimates, specifically examining differences by timing of ART initiation and viral suppression. Data from 14,630 non-breastfeeding mother-infant pairs in metropolitan France between 2000 and 2017 was included. Viral suppression was defined as plasma viral load (VL) < 50 copies/mL, or undetectable if the threshold was higher than 50 copies/mL. Neonatal prophylaxis was prescribed for all infants. In cases where ART was initiated before conception, transmission rates decreased over time, from 0.42% in 2000-2005 to 0.03% in 2011-2017. In women not receiving ART at conception, rates did not differ across time periods: overall rates were 0.52% for women initiating ART < 14 weeks gestation, 0.75% for 14-27 weeks gestation, 1.67% for ≥ 28 weeks gestation, and 8.33% for women not treated during pregnancy. After stratifying by maternal VL near delivery, results were also consistent across time periods: no transmissions were diagnosed in 5,482 infants born to women treated at conception and having undetectable VL near delivery. Among women starting ART during pregnancy and with undetectable VL near delivery, transmission rate was 0.57% (compared to 1.08% for women treated at conception but with detectable VL near delivery).
These findings affirm that the best predictor of low risk of perinatal transmission, among PWH with viral suppression at delivery, is early and sustained ART throughout pregnancy. Further, preconception maternal treatment and undetectable viral load at delivery may somewhat mitigate the effect of preterm birth on transmission. Caution has governed such that most providers are careful not to apply “undetectable equals untransmittable” (U=U) to the context of perinatal transmission, however data from this sizeable cohort are compelling. For people with HIV who wish to become pregnant, findings underscore the importance of broadening ART access and facilitating early treatment initiation with regular VL monitoring to ensure viral suppression near delivery.
The author has no conflicts of interest to disclose.
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