title: Pregnancy and virologic response to antiretroviral therapy in South Africa.
abstract: BACKGROUND
  Although women of reproductive age are the largest group of HIV-infected individuals in sub-Saharan Africa, little is known about the impact of pregnancy on response to highly active antiretroviral therapy (HAART) in that setting. We examined the effect of incident pregnancy after HAART initiation on virologic response to HAART.
  
  
  RESULTS
  We evaluated a prospective clinical cohort of adult women who initiated HAART in Johannesburg, South Africa between 1 April 2004 and 30 September 2009, and followed up until an event, death, transfer, drop-out, or administrative end of follow-up on 31 March 2010. Women over age 45 and women who were pregnant at HAART initiation were excluded from the study; final sample size for analysis was 5,494 women. Main exposure was incident pregnancy, experienced by 541 women; main outcome was virologic failure, defined as a failure to suppress virus to ≤ 400 copies/ml by six months or virologic rebound >400 copies/ml thereafter. We calculated adjusted hazard ratios using marginal structural Cox proportional hazards models and weighted lifetable analysis to calculate adjusted five-year risk differences. The weighted hazard ratio for the effect of pregnancy on time to virologic failure was 1.34 (95% confidence limit [CL] 1.02, 1.78). Sensitivity analyses generally confirmed these main results.
  
  
  CONCLUSIONS
  Incident pregnancy after HAART initiation was associated with modest increases in both relative and absolute risks of virologic failure, although uncontrolled confounding cannot be ruled out. Nonetheless, these results reinforce that family planning is an essential part of care for HIV-positive women in sub-Saharan Africa. More work is needed to confirm these findings and to explore specific etiologic pathways by which such effects may operate.
authors.affiliation: Department of Obstetrics and Gynecology, Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America. daniel.westreich@duke.edu
authors.forename: Daniel
authors.initials: D
authors.lastname: Westreich
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Cole
authors.forename: Shashi
authors.initials: S
authors.lastname: Nagar
authors.forename: Mhairi
authors.initials: M
authors.lastname: Maskew
authors.forename: Charles
authors.initials: C
authors.lastname: van der Horst
authors.forename: Ian
authors.initials: I
authors.lastname: Sanne
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000821:virology; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy* / Q000821:virology
chemical_list: D019380:Anti-HIV Agents