title: Pregnancy incidence and correlates in a clinical trial preparedness study, North West Province South Africa.
abstract: BACKGROUND
  Women in HIV prevention trials often must typically agree to avoid pregnancy. Regardless, some become pregnant. Screening tools predicting pregnancy risk could maximize trial safety and efficiency.
  
  
  OBJECTIVE
  We assessed incidence and correlates of pregnancy among women at high HIV risk.
  
  
  METHODS
  We enrolled sexually-active, HIV-negative women into an observational cohort (2008-2011). At enrollment demographic, contraceptive, reproductive, pregnancy intention and behavioural data were collected. Women reported if one or both partners wanted or intended for the couple to become pregnant. We measured gender role beliefs using a locally validated eight-point index. We tested HIV and pregnancy, and inquired about sexually transmitted infection symptoms (STIs) at enrollment and monthly. HIV testing included behavioural counselling and condom provision, but did not specifically counsel women to avoid pregnancy. Cox proportional hazard modelling evaluated the associations with pregnancy. The multivariate model included the following variables "Recent pregnancy attempts", "Gender Roles Beliefs", "Self-reported STIs" and "Age".
  
  
  RESULTS
  We screened 1068 women and excluded (24.6%, 263/1068) who did not report risk behaviour. Non-pregnant, non-sterilized women aged 18-35 (median = 21 years) enrolled (n = 438). Most women reported one partner (74.7%) and a prior live birth (84.6%). Median follow-up time was 6 months (range 0.7-15.5). Pregnancy incidence was 25.1 per 100 women-years (n = 57 pregnancies). Conservative beliefs on gender roles (Adjusted Hazard Ratio (aHR) 1.8; 95% confidence interval [CI] 1.1-2.9), recent pregnancy attempts (aHR 1.9; 95% CI 1.1-3.4) and baseline self-reported STI (aHR 2.5; 95% CI 1.4-4.4) were associated with increased incident pregnancy. Report of no pregnancy intention was associated with lowered pregnancy risk (aHR 0.3; 95% CI 0.1-0.7).
  
  
  CONCLUSIONS
  We identified new and confirmed existing factors that can facilitate screening for pregnancy risk.
authors.affiliation: The Aurum Institute, Rustenburg, South Africa.
authors.forename: Candice M
authors.initials: CM
authors.lastname: Chetty-Makkan
authors.affiliation: London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Katherine
authors.initials: K
authors.lastname: Fielding
authors.affiliation: FHI 360, Durham, North Carolina, United States of America.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Feldblum
authors.affiliation: International Aids Vaccine Initiative, New York, New York, United States of America; Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Matt A
authors.initials: MA
authors.lastname: Price
authors.affiliation: The Aurum Institute, Rustenburg, South Africa.
authors.forename: Petra
authors.initials: P
authors.lastname: Kruger
authors.affiliation: The Aurum Institute, Rustenburg, South Africa.
authors.forename: Heeran
authors.initials: H
authors.lastname: Makkan
authors.affiliation: The Aurum Institute, Rustenburg, South Africa.
authors.forename: Salome
authors.initials: S
authors.lastname: Charalambous
authors.affiliation: The Aurum Institute, Rustenburg, South Africa.
authors.forename: Mary H
authors.initials: MH
authors.lastname: Latka
mesh_terms: D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic / Q000379:methods / Q000592:standards*; D003267:Contraception / Q000379:methods / Q000523:psychology; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D011247:Pregnancy / Q000706:statistics & numerical data*