The effects of HIV on fertility by infection duration

Abstract

on behalf of the ALPHA network 1 Objectives: To estimate the relationship between HIV natural history and fertility by duration of infection in east and southern Africa before the availability of antiretroviral therapy and assess potential biases in estimates of age-specific subfertility when using retrospective birth histories in cross-sectional studies.Design: Pooled analysis of prospective population-based HIV cohort studies in Masaka (Uganda), Kisesa (Tanzania) and Manicaland (Zimbabwe).Methods: Women aged 15-49 years who had ever tested for HIV were included. Analyses were censored at antiretroviral treatment roll-out. Fertility rate ratios were calculated to see the relationship of duration of HIV infection on fertility, adjusting for background characteristics. Survivorship and misclassification biases on age-specific subfertility estimates from cross-sectional surveys were estimated by reclassifying person-time from the cohort data to simulate cross-sectional surveys and comparing fertility rate ratios with true cohort results.Results: HIV-negative and HIV-positive women contributed 15 440 births and 86 320 person-years; and 1236 births and 11 240 000 person-years, respectively, to the final dataset. Adjusting for age, study site and calendar year, each additional year since HIV seroconversion was associated with a 0.02 (95% confidence interval 0.01-0.03) relative decrease in fertility for HIV-positive women. Survivorship and misclassification biases in simulated retrospective birth histories resulted in modest underestimates of subfertility by 2-5% for age groups 20-39 years.Conclusion: Longer duration of infection is associated with greater relative fertility reduction for HIV-positive women. This should be considered when creating estimates for HIV prevalence among pregnant women and prevention of mother-to-child transmission need over the course of the HIV epidemic and antiretroviral treatment scale up.

The relationship between HIV and fertility in the era of antiretroviral therapy in sub‐Saharan Africa: evidence from 49 Demographic and Health Surveys

“…We corroborated patterns found in previous studies showing increasing HIV-associated subfertility with age [4, 6, 7]. Also consistent with these other studies, we find that in the youngest age group, HIV-positive women have higher fertility than their HIV-negative counterparts as many women in this age group are not sexually active and therefore are not exposed to either HIV or pregnancy.…”

“…We looked at data for the three years prior to the survey when constructing our models as did Chen and Walker; however, we only report results from the first year before the survey due to evidence that using data beyond one year exaggerated the HIV-associated subfertility in younger women (see document, Supplemental Digital Content 1). We also find substantially lower subfertility using the DHS data than we did using data from the demographic surveillance sites in Eastern and Southern Africa [7]. Much of these DSS data are from rural populations around Lake Victoria in East Africa that experienced early and severe HIV epidemics, all factors that we expect to be associated with greater subfertility based on this multicountry analysis.…”

“…This cut-off was used in previous studies [4, 19] to balance the benefits of maximising the person years of observation while seeking to minimise maternal survivorship bias, recall bias and misclassification of HIV status over the three preceding years [7]. However, we report results adjusted for the first year prior to the survey due to evidence of persistence of these biases when using data from longer than a year prior to the survey (see document, Supplemental Digital Content 1, which shows the analysis).…”

“…The fertility of HIV-positive women relative to HIV-negative women steadily declines with age, due to both biological effects of HIV on fecundity [8–10] and differences in exposure to pregnancy including factors such as higher divorce rates and widowhood in HIV-positive women [11]. A few studies have suggested regional differences in HIV-related subfertility [7, 12, 13], although regional variation, is not systematically accounted for in current estimates of PMTCT need.…”

Modelling period fertility: Schooling and intervals following a birth in Eastern Africa

“…HIV infection has both physiological and behavioural effects on fecundity, and the fertility of untreated HIV-infected women is substantially lower than that of the uninfected (Lewis et al 2004). However, this reduction in fertility increases with duration since infection and is greatest in women with symptomatic AIDS (Marston et al 2016). Untreated women living with HIV, whose disease status becomes severe enough to impact greatly on their ability to conceive, will usually die quite quickly.…”