title: Does induced abortion increase the risk of preterm birth? Results from a case-control study.
abstract: OBJECTIVE
  We analyzed the association between previous induced abortions and risk of preterm birth.
  
  
  METHODS
  This was a case-control study. Cases were 502 women who delivered preterm babies at the Clinica Luigi Mangiagalli and the Obstetric and Gynecology Clinic of the University of Verona. Controls were 1,966 women who gave birth at term (> or = 37 weeks of gestation) to healthy infants of normal weight.
  
  
  RESULTS
  The odds ratio for all preterm births was 0.7 (95% CI 0.5-1.1) for women reporting 1 induced abortion and 1.6 (95% CI 0.7-3.5) for those reporting 2 or more induced abortions (chi(2) trend p = 0.81). Previous induced abortions did not increase the risk of preterm birth, both in small and normal for gestational age preterm infants. No difference emerged in risk factors for infants born at <32 and 32-36 gestational weeks.
  
  
  CONCLUSIONS
  This study does not support the suggestion that induced abortions, as performed in Italy during the study period, increase the risk of preterm delivery in subsequent pregnancies.
authors.affiliation: Istituto di Ricerche Farmacologiche Mario Negri, Università di Milano, IT-20122 Milan, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Parazzini
authors.forename: Elena
authors.initials: E
authors.lastname: Ricci
authors.forename: Francesca
authors.initials: F
authors.lastname: Chiaffarino
authors.forename: Sonia
authors.initials: S
authors.lastname: Cipriani
authors.forename: Luca
authors.initials: L
authors.lastname: Tozzi
authors.forename: Luigi
authors.initials: L
authors.lastname: Fedele
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects / Q000706:statistics & numerical data*; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology; D012044:Regression Analysis; D012307:Risk Factors