Paper # 897 
Factors Associated with Viral Load Control and Its Impact on HIV Vertical Trasmission Rates in HIV+ Pregnant Women from Rio De Janeiro during the HAART Era
Esau Joao*1, M I Gouvea1,2, L Sidi1, P Cunha1, C Cardoso1, C Braga1, H Matos1,3, E Martins1, L Ceci1, M L Cruz1, and HSE MCTC Study Group
1Hosp dos Servidores do Estado, Rio de Janeiro, Brazil; 2Inst Oswaldo Cruz, Fiocruz, Brazil; and 3Univ do Estado do Rio de Janeiro, Brazil
Background: Effective use of antiretrovirals (ARV)
in pregnancy and appropriate management of delivery have significantly reduced mother-to-child
transmission (MTCT) rates to <2% in developed countries and in Brazil. HSE, a reference center for prevention of MTCT (PMTCT), has, since 1996, maintained
a cohort of HIV+ pregnant women. This study’s goal was to evaluate
the impact of virologic control (<400 copies) with ARV (HAART vs non-HAART)
in PMTCT.
Methods: From 1996 to 2008, 824 HIV+
pregnant women were selected, who received ARV for at least 4 weeks during
pregnancy and whose viral load was measured at baseline and near delivery; 634
used HAART and 190 used non-HAART. Of these, 117 had an undetectable viral load
(<400 copies/mL) at baseline and were excluded from analysis. Statistical
analysis was performed using SPSS, v 13.0. Means were compared using t test,
Mann-Whitney, ANOVA, or Kruskall-Wallis methods. Multivariate analysis was
employed using binary logistic unconditional models.
Results: In the 824 pregnant women, the median
gestational age for initiating ARV was 21 weeks. At baseline, median CD4 count
was 371, and near delivery was 462 cells/mm3. Median viral load at
baseline was 8599 (3.93 log) and near to delivery 400 (2.6 log) copies/mL. Subsequent
analysis included only 707 women who had baseline viral load >400 copies/mL.
Global effectiveness in viral control was 57% (n = 403), with HAART was 65% (n =
346) and non-HAART was 26% (n = 39). Vertical transmission rate was reduced
significantly with viral control (see the figure). Vertical transmission rates
were 0.25% (CI95% 0.01 to 1.62) for <400 copies; 1.38% (CI95% 0.17 to 9.6)
for copies 400 to 1000; and 4% (CI95% 1.96 to 7.71) for >1000 copies.
c2 for trend P <0.01
Using a logistic model, HAART was associated with a 4-fold
increase in viral control when compared non-HAART (OR = 4.15, 95%CI 2.9 to 5.95)
and use of ARV >12 weeks (OR = 2.75, 95%CI1.96 to 3.85) was associated to
successful viral control. CD4 near delivery >400 (OR = 1.55, 95%CI 1.08 to 2.2)
was also statistically associated to successful viral control. The newborn
outcomes low birth weight <2500 g with HAART was 15.3%, non-HAART 10.25% (P
= 0.40) and preterm birth <37 weeks with HAART was 8.8% and non-HAART
was 5.12% (P = 0.43).
Conclusions: Viral control (viral load <400 copies/mL),
especially with HAART use and CD4 cell count >400 near delivery and use of
ART >12 weeks did reduce MTCT. Efforts to start ARV early during the
pregnancy and reach viral control near delivery should be the goal of PMTCT.
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