Viral suppression among HIV-positive women starting antiretroviral therapy (ART) before or during pregnancy in Lesotho

Background: Reaching maximal viral suppression is critical for preventing perinatal transmission. One hypothesized benefit of lifelong ART for all HIV-positive women (Option B+) is improved viral suppression in subsequent pregnancies.
Methods: This is an observational prospective cohort study of HIV-positive pregnant women conducted at 13 clinics in three Lesotho districts. Factors associated with HIV viral load (VL) suppression were assessed. VL was obtained between June 2014-November 2015 in 104 women at enrollment (any ANC visit) and delivery. Three women were excluded because of missing ART dates; 13 were excluded because delivery VL was obtained ≥3 weeks post-delivery. Undetectable VL was defined as < 20 c/mL (Roche CAP/CTM v2). Adherence was measured by seven-day self-reported recall. Logistic regression analysis was conducted to detect an association between ART initiation timing and undetectable VL.
Results: All women received NNRTI-based ART (85.2% Efavirenz-based); 75/88 (87.2%) reported 100% adherence. Mean ART duration was 40.8 months in women starting ART prior to pregnancy (n=43) and 4.1 months for those starting during ANC (n=45); only 3/88 (3.4%) had < 4 weeks ART. Enrollment VL was undetectable in 26/43 (60.5%) women starting ART pre-pregnancy and 10/45 (22.2%) starting during-ANC. Delivery VL was undetectable in 32/43 (74.4%) women on ART pre-pregnancy and 18/45 (40.0%) of women who started ART during-ANC. Of 52 women with detectable enrollment VL, 18 (34.6%, 9 pre-pregnancy, 9 during-ANC) achieved undetectable VL by delivery. Four women with undetectable enrollment VL experienced a VL increase by delivery
(3 pre-pregnancy, 1 during-ANC). Women starting ART pre-pregnancy were 5.4 and 4.3 times more likely to have undetectable VL at enrollment (p< 0.0001) and delivery (p< 0.001), respectively, than those starting during-ANC. Fifty women (56.8%) had delivery VL < 20 c/mL, 19 (21.6%) had 20-999 c/mL and 19 (21.6%) had >1,000 c/mL.
Conclusions: Most women received >4 weeks ART and reported high adherence. However, only 56.8% achieved profound viral suppression to < 20 c/mL; 78.4% reached suppression to < 1,000 c/mL. While women starting ART pre-pregnancy were more likely to have undetectable VL than those starting during-ANC, almost one quarter still had VL >20 c/mL at delivery, with 11.6% having VL >1,000 c/mL.

M.M. Gill1, Y. Nelson2, A. Tiam3, S. Mohale3, M. Mokone3, S. Kassaye4, L. Mofenson1, L. Guay1,2
1Elizabeth Glaser Pediatric AIDS Foundation-Global, Washington, United States, 2George Washington University, Milken Institute School of Public Health, Washington, United States, 3Elizabeth Glaser Pediatric AIDS Foundation - Lesotho, Maseru, Lesotho, 4Georgetown University, Washington, United States