title: Incident HIV during pregnancy and postpartum and risk of mother-to-child HIV transmission: a systematic review and meta-analysis.
abstract: BACKGROUND
  Women may have persistent risk of HIV acquisition during pregnancy and postpartum. Estimating risk of HIV during these periods is important to inform optimal prevention approaches. We performed a systematic review and meta-analysis to estimate maternal HIV incidence during pregnancy/postpartum and to compare mother-to-child HIV transmission (MTCT) risk among women with incident versus chronic infection.
  
  
  RESULTS
  We searched PubMed, Embase, and AIDS-related conference abstracts between January 1, 1980, and October 31, 2013, for articles and abstracts describing HIV acquisition during pregnancy/postpartum. The inclusion criterion was studies with data on recent HIV during pregnancy/postpartum. Random effects models were constructed to pool HIV incidence rates, cumulative HIV incidence, hazard ratios (HRs), or odds ratios (ORs) summarizing the association between pregnancy/postpartum status and HIV incidence, and MTCT risk and rates. Overall, 1,176 studies met the search criteria, of which 78 met the inclusion criterion, and 47 contributed data. Using data from 19 cohorts representing 22,803 total person-years, the pooled HIV incidence rate during pregnancy/postpartum was 3.8/100 person-years (95% CI 3.0-4.6): 4.7/100 person-years during pregnancy and 2.9/100 person-years postpartum (p = 0.18). Pooled cumulative HIV incidence was significantly higher in African than non-African countries (3.6% versus 0.3%, respectively; p<0.001). Risk of HIV was not significantly higher among pregnant (HR 1.3, 95% CI 0.5-2.1) or postpartum women (HR 1.1, 95% CI 0.6-1.6) than among non-pregnant/non-postpartum women in five studies with available data. In African cohorts, MTCT risk was significantly higher among women with incident versus chronic HIV infection in the postpartum period (OR 2.9, 95% CI 2.2-3.9) or in pregnancy/postpartum periods combined (OR 2.3, 95% CI 1.2-4.4). However, the small number of studies limited power to detect associations and sources of heterogeneity.
  
  
  CONCLUSIONS
  Pregnancy and the postpartum period are times of persistent HIV risk, at rates similar to "high risk" cohorts. MTCT risk was elevated among women with incident infections. Detection and prevention of incident HIV in pregnancy/postpartum should be prioritized, and is critical to decrease MTCT.
authors.affiliation: Department of Global Health, University of Washington, Seattle, Washington, United States of America.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Drake
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, Washington, United States of America.
authors.forename: Anjuli
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Department of Global Health, University of Washington, Seattle, Washington, United States of America ; Department of Biostatistics, University of Washington, Seattle, Washington, United States of America ; Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.
authors.forename: Barbra
authors.initials: B
authors.lastname: Richardson
authors.affiliation: Department of Global Health, University of Washington, Seattle, Washington, United States of America ; Department of Epidemiology, University of Washington, Seattle, Washington, United States of America ; Department of Medicine, University of Washington, Seattle, Washington, United States of America ; Department of Pediatrics, University of Washington, Seattle, Washington, United States of America.
authors.forename: Grace
authors.initials: G
authors.lastname: John-Stewart
mesh_terms: D000349:Africa / Q000453:epidemiology; D019380:Anti-HIV Agents / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D015994:Incidence; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D015999:Multivariate Analysis; D016017:Odds Ratio; D049590:Postpartum Period; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D019380:Anti-HIV Agents