title: Measuring the Impact of Antiretroviral Therapy Roll-Out on Population Level Fertility in Three African Countries.
abstract: BACKGROUND
  UNAIDS official estimates of national HIV prevalence are based on trends observed in antenatal clinic surveillance, after adjustment for the reduced fertility of HIV positive women. Uptake of ART may impact on the fertility of HIV positive women, implying a need to re-estimate the adjustment factors used in these calculations. We analyse the effect of antiretroviral therapy (ART) provision on population-level fertility in Southern and East Africa, comparing trends in HIV infected women against the secular trends observed in uninfected women.
  
  
  METHODS
  We used fertility data from four community-based demographic and HIV surveillance sites: Kisesa (Tanzania), Masaka and Rakai (Uganda) and uMkhanyakude (South Africa). All births to women aged 15-44 years old were included in the analysis, classified by mother's age and HIV status at time of birth, and ART availability in the community. Calendar time period of data availability relative to ART Introduction varied across the sites, from 5 years prior to ART roll-out, to 9 years after. Calendar time was classified according to ART availability, grouped into pre ART, ART introduction (available in at least one health facility serving study site) and ART available (available in all designated health facilities serving study site). We used Poisson regression to calculate age adjusted fertility rate ratios over time by HIV status, and investigated the interaction between ART period and HIV status to ascertain whether trends over time were different for HIV positive and negative women.
  
  
  RESULTS
  Age-adjusted fertility rates declined significantly over time for HIV negative women in all four studies. However HIV positives either had no change in fertility (Masaka, Rakai) or experienced a significant increase over the same period (Kisesa, uMkhanyakude). HIV positive fertility was significantly lower than negative in both the pre ART period (age adjusted fertility rate ratio (FRR) range 0.51 95%CI 0.42-0.61 to 0.73 95%CI 0.64-0.83) and when ART was widely available (FRR range 0.57 95%CI 0.52-0.62 to 0.83 95%CI 0.78-0.87), but the difference has narrowed. The interaction terms describing the difference in trends between HIV positives and negatives are generally significant.
  
  
  CONCLUSIONS
  Differences in fertility between HIV positive and HIV negative women are narrowing over time as ART becomes more widely available in these communities. Routine adjustment of ANC data for estimating national HIV prevalence will need to allow for the impact of treatment.
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Milly
authors.initials: M
authors.lastname: Marston
authors.affiliation: Medical Research Council, Entebbe, Uganda.
authors.forename: Jessica
authors.initials: J
authors.lastname: Nakiyingi-Miiro
authors.affiliation: Africa Centre for Health and Population Studies, University of KwaZulu-Natal, Somkhele, South Africa.|Faculty of Medicine, Faculty of Social and Human Sciences, University of Southampton, Southampton, United Kingdom.
authors.forename: Victoria
authors.initials: V
authors.lastname: Hosegood
authors.affiliation: TAZAMA Project, National Institute of Medical Research, Mwanza, Tanzania.
authors.forename: Tom
authors.initials: T
authors.lastname: Lutalo
authors.affiliation: Rakai Health Sciences Program, Kalisizo, Rakai, Uganda.
authors.forename: Baltazar
authors.initials: B
authors.lastname: Mtenga
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Basia
authors.initials: B
authors.lastname: Zaba
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D005260:Female; D005298:Fertility / Q000187:drug effects*; D006678:HIV / Q000472:pathogenicity; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D013019:South Africa; D013636:Tanzania; D014454:Uganda
chemical_list: D044966:Anti-Retroviral Agents