Background:  There is no single source of nationally representative data upon which to base estimates of the number of births to HIV⁺ women in the United States. Using HIV surveillance data, back-calculation of undiagnosed HIV prevalence, and data from the Adult Spectrum of Disease (ASD) study, we estimated the total number of births to HIV⁺ women in the US in 2006.

Methods:  A Poisson regression model was used to estimate the total number of women (13 to 44 years of age) living with diagnosed HIV (not AIDS) in the US in 2006 based on reported data from 33 states that conducted confidential name-based HIV case reporting. This model took into account AIDS incidence and deaths, stratified by race/ethnicity and age groups. Approximate 95% confidence intervals were derived. To estimate the number of undiagnosed HIV⁺ women of child-bearing age, a back-calculation model was then used, incorporating surveillance data reported through June 2007. Next, AIDS cases were estimated based on surveillance data from 50 states and the District of Columbia. Finally, births were estimated for the total number of women living with HIV disease, HIV (not AIDS), immunologic AIDS, and clinical AIDS using observed pregnancy rates from ASD. 

Results:  A total of 111,332 women were diagnosed and living with HIV (not AIDS). After adjustment to estimate undiagnosed HIV⁺ women, 125,050 to 128,653 women were living with HIV (not AIDS) and had an estimated 7021 to 7272 births. A total of 56,822 women aged 13 to 44 years were living with AIDS (immunologic 55%, 899 births, clinical 45%, 730 births) in 2006. The estimated number of births in 2006 to all women living with HIV disease was 8650 to 8900, approximately 30% higher than the estimated number of total births (6075 to 6422 in 2000).

Conclusions:  Although perinatal HIV infections are declining with the advent of highly effective ART and with the success of US Public Health Service recommendations during the past decade, the number of births to HIV-infected women has increased. This increase highlights the need to continue and strengthen efforts to prevent perinatal HIV transmission in the United States.