title: The risk of viral rebound in the year after delivery in women remaining on antiretroviral therapy.
abstract: OBJECTIVE
  The objective of this study is to assess the risk of viral rebound in postpartum women on suppressive combination antiretroviral therapy (cART).
  
  
  METHODS
  Using data from the UK Collaborative HIV Cohort (UK CHIC) study and the UK and Ireland National Study of HIV in Pregnancy and Childhood (NSHPC), women with HIV-RNA 50 copies/ml or less at delivery in 2006-2011, who started life-long cART during pregnancy (n = 321) or conceived on cART (n = 618), were matched by age, duration on cART and time period, with at least one control (non-postpartum). The cumulative probability of viral rebound (HIV-RNA >200 copies/ml) was assessed by Kaplan-Meier analysis; adjusted hazard ratios (aHRs) for the 0-3 and 3-12 months postdelivery (cases)/pseudo-delivery (controls) were calculated in Cox proportional hazards models.
  
  
  RESULTS
  In postpartum women who conceived on cART, 5.9% [95% confidence interval (95% CI) 4.0-7.7] experienced viral rebound by 3 months, and 2.2% (1.4-3.0%) of their controls. The risk of viral rebound was higher in postpartum women than in controls during the first 3 months [aHR 2.63 (1.58-4.39)] but not during the 3-12 months postdelivery/pseudo-delivery. In postpartum women who started cART during pregnancy, 27% (22-32%) experienced viral rebound by 3 months, and 3.0% (1.6-4.4%) of their controls. The risk of viral rebound was higher in postpartum women than in controls during both postdelivery/pseudo-delivery periods [<3 months: aHR 6.63 (3.58-12.29); 3-12 months: aHR 4.05 (2.03-8.09)].
  
  
  CONCLUSIONS
  In women on suppressive cART, the risk of viral rebound is increased following delivery, especially in the first 3 months, which may be related to reduced adherence, indicating the need for additional adherence support for postpartum women.
authors.affiliation: aPopulation, Policy and Practice Programme, UCL Institute of Child Health bHIV Epidemiology and Biostatistics Group, UCL Research Department of Infection and Population Health, London cHuman Development and Health, Faculty of Medicine, Southampton General Hospital, University of Southampton, Southampton dHomerton University Hospital NHS Foundation Trust eSection of Retrovirology and GU Medicine, Imperial College, London, UK fAfrica Centre for Health and Population Studies, University of KwaZulu-Natal, Mtubatuba, South Africa.
authors.forename: Susie
authors.initials: S
authors.lastname: Huntington
authors.forename: Claire
authors.initials: C
authors.lastname: Thorne
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Newell
authors.forename: Jane
authors.initials: J
authors.lastname: Anderson
authors.forename: Graham P
authors.initials: GP
authors.lastname: Taylor
authors.forename: Deenan
authors.initials: D
authors.lastname: Pillay
authors.forename: Teresa
authors.initials: T
authors.lastname: Hill
authors.forename: Pat A
authors.initials: PA
authors.lastname: Tookey
authors.forename: Caroline
authors.initials: C
authors.lastname: Sabin
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D007494:Ireland; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D036801:Parturition; D049590:Postpartum Period; D011247:Pregnancy; D012008:Recurrence; D018570:Risk Assessment; D006113:United Kingdom; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents