title: High medication adherence during periconception periods among HIV-1-uninfected women participating in a clinical trial of antiretroviral pre-exposure prophylaxis.
abstract: BACKGROUND
  Pre-exposure prophylaxis (PrEP) may be an important safer conception strategy for HIV-1-uninfected women with HIV-1-infected partners. Understanding medication adherence in this population may inform whether PrEP is a feasible safer conception strategy.
  
  
  METHODS
  We evaluated predictors of pregnancy and adherence to study medication among HIV-1-uninfected women enrolled in a randomized placebo-controlled trial of PrEP among African HIV-1-serodiscordant couples. Participants were counseled on HIV-1 risk reduction, contraception, and adherence and tested for pregnancy at monthly study visits. Pill counts of dispensed drug were performed and, at a subset of visits, plasma was collected to measure active drug concentration.
  
  
  RESULTS
  Among 1785 women, pregnancy incidence was 10.2 per 100 person-years. Younger age, not using contraception, having an additional sexual partner, and reporting unprotected sex were associated with increased likelihood of pregnancy. Monthly clinic pill counts estimated that women experiencing pregnancy took 97% of prescribed doses overall, with at least 80% pill adherence for 98% of study months, and no difference in adherence in the periconception period compared with previous periods (P = 0.98). Tenofovir was detected in plasma at 71% of visits where pregnancy was discovered. By multiple measures, adherence was similar for women experiencing and not experiencing pregnancy (P ≥ 0.1).
  
  
  CONCLUSIONS
  In this clinical trial of PrEP, pregnancy incidence was 10% per year despite excellent access to effective contraception. Women experiencing pregnancy had high medication adherence, suggesting that PrEP may be an acceptable and feasible safer conception strategy for HIV-1-uninfected women with HIV-1-serodiscordant partners.
authors.affiliation: *Division of Infectious Disease and Center for Global Health, Massachusetts General Hospital, Boston, MA; †Division of Infectious Disease, Beth Israel Deaconess Medical Center, Boston, MA; ‡Department of Global Health, University of Washington, Seattle, WA; §Kenya Medical Research Institute, Nairobi, Kenya; ‖Department of Obstetrics, Gynecology and Reproductive Sciences, Bixby Center for Global Reproductive Health, University of California San Francisco, San Francisco, CA; ¶Department of Medicine, Johns Hopkins University, Baltimore, MD; #Department of Medicine, University of Washington, Seattle, WA; and **Department of Epidemiology, University of Washington, Seattle, WA.
authors.forename: Lynn T
authors.initials: LT
authors.lastname: Matthews
authors.forename: Renee
authors.initials: R
authors.lastname: Heffron
authors.forename: Nelly R
authors.initials: NR
authors.lastname: Mugo
authors.forename: Craig R
authors.initials: CR
authors.lastname: Cohen
authors.forename: Craig W
authors.initials: CW
authors.lastname: Hendrix
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
authors.forename: David R
authors.initials: DR
authors.lastname: Bangsberg
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000097:blood; D015331:Cohort Studies; D004311:Double-Blind Method; D005260:Female; D005306:Fertilization; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D055118:Medication Adherence; D063065:Organophosphonates / Q000008:administration & dosage* / Q000097:blood; D065129:Pre-Exposure Prophylaxis / Q000379:methods* / Q000592:standards; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D016016:Proportional Hazards Models; D012044:Regression Analysis; D000068698:Tenofovir; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine