title: Placenta previa and risk of major congenital malformations among singleton births in Finland.
abstract: BACKGROUND
  Placenta previa has been associated with adverse birth outcomes, but its association with congenital malformations is inconclusive. We examined the association between placenta previa and major congenital malformations among singleton births in Finland.
  
  
  METHODS
  We performed a retrospective population register-based study on all singletons born at or after 22+0 weeks of gestation in Finland during 2000 to 2010. We linked three national health registers: the Finnish Medical Birth Register, the Hospital Discharge Register, and the Register of Congenital Malformations, and examined several demographic and clinical characteristics among women with and without placenta previa, in association with major congenital malformations. We estimated adjusted odds ratios and 95% confidence intervals using multivariable logistic regression models.
  
  
  RESULTS
  The prevalence of placenta previa was estimated as 2.65 per 1000 singleton births in Finland (95% confidence interval, 2.53-2.79). Overall, 6.2% of women with placenta previa delivered a singleton infant with a major congenital malformation, compared with 3.8% of unaffected women (p ≤ 0.001). Placenta previa was positively associated with almost 1.6-fold increased risk of major congenital malformations in the offspring, after controlling for maternal age, parity, fetal sex, smoking, socio-economic status, chorionic villus biopsy, In vitro fertilization, pre-existing diabetes, depression, preeclampsia, and prior caesarean section (adjusted odds ratio = 1.55; 95% confidence interval, 1.27-1.90).
  
  
  CONCLUSIONS
  Using a large population-based study, we found that placenta previa was weakly, but significantly associated with an increased risk of major congenital malformations in singleton births. Future studies should examine the association between placenta previa and individual types of congenital malformations, specifically in high-risk pregnancies.
authors: Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia.
authors: Vijaya
authors: V
authors: Kancherla
authors: Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia.|Department of Obstetrics and Gynecology, Kuopio University Hospital, Kuopio, Finland.
authors: Sari
authors: S
authors: Räisänen
authors: National Institute for Health and Welfare, Helsinki, Finland.|Nordic School of Public Health, Gothenburg, Sweden.
authors: Mika
authors: M
authors: Gissler
authors: Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, Georgia.
authors: Michael R
authors: MR
authors: Kramer
authors: Department of Obstetrics and Gynecology, Kuopio University Hospital, Kuopio, Finland.|School of Medicine, University of Eastern Finland, Kuopio, Finland.
authors: Seppo
authors: S
authors: Heinonen
mesh_terms: D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D016017:Odds Ratio; D010923:Placenta Previa / Q000453:epidemiology*; D011247:Pregnancy; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors
keywords: birth defects; congenital malformation; placenta previa; population register; pregnancy