Trends of and factors associated with live-birth and abortion rates among HIV-positive and HIV-negative women

Abstract

Background: Little is known about fertility choices and pregnancy outcome rates among HIV-infected women in the current combination antiretroviral treatment era.

Objective: We sought to describe trends and factors associated with live-birth and abortion rates among HIV-positive and high-risk HIV-negative women enrolled in the Women's Interagency HIV Study in the United States.

Study design: We analyzed longitudinal data collected from Oct. 1, 1994, through Sept. 30, 2012, through the Women's Interagency HIV Study. Age-adjusted rates per 100 person-years live births and induced abortions were calculated by HIV serostatus over 4 time periods. Poisson mixed effects models containing variables associated with live births and abortions in bivariable analyses (P < .05) generated adjusted incidence rate ratios and 95% confidence intervals.

Results: There were 1356 pregnancies among 2414 women. Among HIV-positive women, age-adjusted rates of live birth increased from 1994 through 1997 to 2006 through 2012 (2.85-7.27/100 person-years, P trend < .0001). Age-adjusted rates of abortion in HIV-positive women remained stable over these time periods (4.03-4.29/100 person-years, P trend = .09). Significantly lower live-birth rates occurred among HIV-positive compared to HIV-negative women in 1994 through 1997 and 1997 through 2001, however rates were similar during 2002 through 2005 and 2006 through 2012. Higher CD4⁺ T cells/mm³ (≥350 adjusted incidence rate ratio, 1.39 [95% CI 1.03-1.89] vs <350) were significantly associated with increased live-birth rates, while combination antiretroviral treatment use (adjusted incidence rate ratio, 1.35 [95% CI 0.99-1.83]) was marginally associated with increased live-birth rates. Younger age, having a prior abortion, condom use, and increased parity were associated with increased abortion rates among both HIV-positive and HIV-negative women. CD4⁺ T-cell count, combination antiretroviral treatment use, and viral load were not associated with abortion rates.

Conclusion: Unlike earlier periods (pre-2001) when live-birth rates were lower among HIV-positive women, rates are now similar to HIV-negative women, potentially due to improved health status and combination antiretroviral treatment. Abortion rates remain unchanged, illuminating a need to improve contraceptive services.

Keywords: HIV; abortion; antiretroviral therapy; live birth; pregnancy.