Pregnancy and HIV disease progression during the era of highly active antiretroviral therapy.

BACKGROUND: Before the availability of highly active antiretroviral therapy (HAART), there was no clear effect of pregnancy on human immunodeficiency virus (HIV) disease progression. This has not been assessed during the HAART era.
METHODS: We conducted an observational cohort study among HIV-infected women with >or=1 outpatient clinic visit between January 1997 and December 2004. HIV disease progression was defined as the occurrence of an AIDS-defining event or death.
RESULTS: Of 759 women who met the inclusion criteria, 139 (18%) had had >1 pregnancy, and 540 (71%) had received HAART. There was no difference in HAART duration by pregnancy status. Eleven pregnant (8%) and 149 nonpregnant (24%) women progressed to AIDS or death. After controlling for age, baseline CD4(+) lymphocyte count, baseline HIV-1 RNA level, and durable virologic suppression in a Cox proportional hazards model that included propensity score for pregnancy, pregnancy was associated with a decreased risk of disease progression (hazard ratio [HR], 0.40 [95% confidence interval {CI}, 0.20-0.79]; P=.009]). In a matched-pair analysis of 81 pregnant women matched to 81 nonpregnant women according to age, baseline CD4(+) lymphocyte count, receipt of HAART, and date of cohort entry, pregnant women had a lower risk of disease progression both before (HR, 0.10 [95% CI, 0.01-0.89]; P=.04) and after (HR, 0.44 [95% CI, 0.19-1.00]; P=.05) the pregnancy event.
CONCLUSION: Pregnancy was associated with a lower risk of HIV disease progression in this HAART-era study. This finding could be the result of the healthier immune status of women who become pregnant or could possibly be related to a beneficial interaction between pregnancy and HAART.