title: Contraception use and impact on pregnancy prevention in women participating in an HIV prevention trial in South Africa.
abstract: BACKGROUND
  Unplanned pregnancy rates in South Africa are high. Effective use of contraception is therefore an essential public health intervention to prevent unplanned pregnancies. This study describes contraception use and its impact on pregnancy in women participating in HIV prevention research and its implications for public health practice.
  
  
  METHODS
  A secondary analysis of sociodemographic, behavioural, contraception use, and pregnancy incidence data was conducted amongst women participating in the Microbicides Development Programme (MDP) 301 trial conducted in Durban, South Africa. Log-rank tests were carried out to compare the pregnancy incidence between women who reported use of injectable contraceptive methods compared to women using oral contraceptive pills, using condoms and other methods (intrauterine device, traditional methods and natural methods). The effect of types of contraceptives on pregnancy incidence was assessed using Cox proportional hazards regression models.
  
  
  RESULTS
  Of the 2018 women enrolled, injectable contraception was the most commonly used method (52%) compared to pills, condoms for pregnancy prevention and other methods. Injectable contraception use was associated with lower crude pregnancy incidence of 4.4 per 100 woman-years [95% confidence interval (95% CI 3.3-5.9)] compared to women using pills [19.3 per 100 woman-years (95% CI 13.3-28.0)], condoms [19.7 per 100 woman-years (95% CI 16.3-23.6)] and other methods [11.5 per 100 woman-years (95% CI 7.5-17.6)]. This effect remained significant when adjusted for age, level of education, condom use at last sex act [hazard ratio 0.27, (95% CI 0.16-0.47, p<0.001)].
  
  
  CONCLUSIONS
  Injectable contraception offered a high level of protection against pregnancies among women in Durban.
  
  
  BACKGROUND
  ISRCTN64716212.
authors.affiliation: Senior Scientist, HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa.
authors.forename: Jayajothi
authors.initials: J
authors.lastname: Moodley
authors.affiliation: Senior Scientist, HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa.
authors.forename: Sarita
authors.initials: S
authors.lastname: Naidoo
authors.affiliation: Biostatistician, The Kirby Institute, University of New South Wales, Sydney, Australia.
authors.forename: Handan
authors.initials: H
authors.lastname: Wand
authors.affiliation: Chief Specialist Scientist, Director, HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa; and Honorary Professor, Department of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Gita
authors.initials: G
authors.lastname: Ramjee
mesh_terms: D000328:Adult; D003267:Contraception / Q000706:statistics & numerical data*; D003268:Contraception Behavior / Q000706:statistics & numerical data; D003271:Contraceptive Agents, Female / Q000008:administration & dosage*; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D011295:Prenatal Care / Q000379:methods*; D013019:South Africa; D055815:Young Adult
chemical_list: D003271:Contraceptive Agents, Female
keywords: HIV prevention; condoms; injectable contraception; oral contraceptives; pregnancy rates