title: A score for assessing the risk of first-time adolescent pregnancy.
abstract: BACKGROUND
  Adolescent pregnancy is an important health issue. Prevention programs are usually aimed at the prevention of repeat pregnancy, ignoring the adolescents at risk of becoming pregnant for the first time.
  
  
  OBJECTIVE
  To analyse if socio-economic status, family type and mother's age at first pregnancy are risk factors for adolescent pregnancy and to design a risk score of first-time adolescent pregnancy.
  
  
  METHODS
  A case-control study was performed: cases were primiparous adolescents and controls were primiparous adult women. Participants were asked about their socio-economic status and family structure during adolescence and the age at which their mothers' first pregnancy occurred. Odds ratio (OR) and 95% confidence intervals were calculated. A first-time adolescent pregnancy risk score was designed based on a multiple logistic regression model.
  
  
  RESULTS
  Sixty-six adolescents and 140 adults were interviewed. Belonging to a family other than nuclear or extended types was an independent risk factor for adolescent pregnancy (OR 9.37, 95% CI 3.36-38.07). Low socio-economic status and having a mother with history of adolescent pregnancy were not independent risk factors (OR 1.04, 95% CI 0.34-5.11 and OR 1.13, 95% CI 0.42-4.32, respectively), achieving significance only when simultaneously present (OR 6.01, 95% CI 2.36-20.79). The presence of all these factors determined the highest adolescent pregnancy probability (OR 10.49, 95% CI 3.43-51.00). A first-time adolescent pregnancy risk assessment score was designed, with an estimated sensitivity of 75.8% and specificity of 75.0%.
  
  
  CONCLUSIONS
  Adolescent pregnancy is associated with unfavorable precedents that can be used to identify adolescents at increased risk of early pregnancy.
authors.affiliation: Department of Pediatrics, S. Teotónio's Hospital Empresa Pública Empresarial, Viseu, Portugal.
authors.forename: Maria Inês
authors.initials: MI
authors.lastname: Santos
authors.forename: Frederico
authors.initials: F
authors.lastname: Rosário
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005191:Family Characteristics; D005260:Female; D006801:Humans; D016015:Logistic Models; D008423:Maternal Age; D015999:Multivariate Analysis; D016017:Odds Ratio; D010298:Parity; D011174:Portugal; D011247:Pregnancy; D011253:Pregnancy in Adolescence / Q000517:prevention & control*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012959:Socioeconomic Factors