Abstract Body

Background: Prior to introduction of tenofovir/emtricitabine/efavirenz (TDF/FTC/EFV, Atripla), 3-drug antiretroviral treatment (ART) was associated with increased adverse birth outcomes compared with zidovudine (ZDV) used for prevention of mother-to-child HIV transmission (PMTCT). We evaluated adverse birth outcomes among pregnant women initiating Atripla vs. other ART and ZDV.

Methods: We extracted obstetric records from HIV+ women at the 2 largest maternities in Botswana from 2009-11 when Botswana National Guidelines recommended ZDV from 28 weeks gestational age (GA) for CD4 >350 and ART for CD4 <350, and again in 2013-14 after implementation of Atripla for PMTCT regardless of CD4 or GA. Outcomes included small for gestational age (SGA) (<10th% birthweight for gestational age), preterm delivery (PTD) (<37 weeks GA) and stillbirths (SB). Using logistic regression, we compared women who initiated Atripla vs. other ART (restricting analyses CD4 <350); Atripla vs. ZDV (restricting analyses to CD4 >350); and Atripla vs. any other ARV in pregnancy. Comparisons included only ARV starts before 30 wks GA and outcomes >30 wks GA.

Results: Data were collected on 5247 women who initiated ARVs in pregnancy: 1468 (28%) initiated Atripla; 772 (15%) other 3-drug ART combinations; 2929 (56%) zidovudine (ZDV); and 78 (1.5%) unspecified ARVs. Pregnancy CD4 count was available in 59%, and 70% started ARVs by 30 wks GA. Prevalence of adverse birth outcomes was high overall (18% SGA, 21% PTD and 3% SB), and among women initiating Atripla (12% SGA, 22% PTD and 3% SB). Compared with initiating other ART in pregnancy, Atripla had fewer SGA infants (aOR 0.4, 95% CI 0.2,0.7) and no significant differences in PTD (aOR 1.3, 95%CI 0.8,2.4) or SB (aOR 0.5, 95%CI 0.1,1.5). Compared with initiating ZDV, Atripla may have had fewer SGA infants (aOR 0.7, 95%CI 0.5,1.0) and no difference in PTD (aOR 1.0, 95%CI 0.7,1.4) or SB (aOR 1.0, 95% CI 0.4,2.1). Compared with initiating any other ARV (ART or ZDV) without CD4 restriction, Atripla had fewer SGA infants (aOR 0.6, 95% CI 0.4,0.8) and no difference in PTD (aOR 1.0, 95%CI 0.8,1,3) or SB (aOR 0.8, 95% CI 0.4,1.5).

Conclusions: Adverse birth outcomes remain high among HIV+ women in Botswana. Atripla appeared at least as safe as other ARVs started by 30 weeks gestation, and was associated with fewer SGA infants. Larger studies with Atripla exposures from conception are needed to evaluate earlier pregnancy outcomes and neural tube defects.