title: Chronic hypertension in pregnancy and the risk of congenital malformations: a cohort study.
abstract: OBJECTIVE
  Chronic hypertension is a common medical condition in pregnancy. The purpose of the study was to examine the association between maternal chronic hypertension and the risk of congenital malformations in the offspring.
  
  
  METHODS
  We defined a cohort of 878,126 completed pregnancies linked to infant medical records using the Medicaid Analytic Extract. The risk of congenital malformations was compared between normotensive controls and those with treated and untreated chronic hypertension. Confounding was addressed using propensity score matching.
  
  
  RESULTS
  After matching, compared with normotensive controls, pregnancies complicated by treated chronic hypertension were at increased risk of congenital malformations (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.2-1.5), as were pregnancies with untreated chronic hypertension (OR 1.2; 95% CI, 1.1-1.3). In our analysis of organ-specific malformations, both treated and untreated chronic hypertension was associated with a significant increase in the risk of cardiac malformations (OR, 1.6; 95% CI, 1.4-1.9 and OR, 1.5; 95% CI, 1.3-1.7, respectively). These associations persisted across a range of sensitivity analyses.
  
  
  CONCLUSIONS
  There is a similar increase in the risk of congenital malformations (particularly cardiac malformations) associated with treated and untreated chronic hypertension that is independent of measured confounders. Studies evaluating the teratogenic potential of antihypertensive medications must control for confounding by indication. Fetuses and neonates of mothers with chronic hypertension should be carefully evaluated for potential malformations, particularly cardiac defects.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; Department of Anesthesiology, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA. Electronic address: bbateman@partners.org.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Bateman
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Krista F
authors.initials: KF
authors.lastname: Huybrechts
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fischer
authors.affiliation: Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Ellen W
authors.initials: EW
authors.lastname: Seely
authors.affiliation: Department of Obstetrics and Gynecology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Ecker
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Oberg
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Franklin
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Helen
authors.initials: H
authors.lastname: Mogun
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Sonia
authors.initials: S
authors.lastname: Hernandez-Diaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002908:Chronic Disease; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000209:etiology*; D005260:Female; D006330:Heart Defects, Congenital / Q000209:etiology; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D007231:Infant, Newborn; D016015:Logistic Models; D016017:Odds Ratio; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000188:drug therapy; D057216:Propensity Score; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000959:Antihypertensive Agents
keywords: birth defect; drug; epidemiology; hypertension; pregnancy