title: The safety of calcium channel blockers in human pregnancy: a prospective, multicenter cohort study.
abstract: OBJECTIVE
  Our purpose was to examine the potential teratogenicity of calcium channel blockers.
  
  
  METHODS
  Six teratogen information services prospectively collected and followed up 78 women with first-trimester exposure to calcium channel blockers. Pregnancy outcome was compared (by paired t text of chi2 analysis) with that of a control group matched for maternal age and smoking.
  
  
  RESULTS
  There was no increase in major malformation (2/66=3.0% [calcium channel blockers] vs 0% [nonteratogenic controls], p=0.27); a fivefold increase was ruled out (baseline 2%, alpha = 0.05, beta = 0.20). The defects reported were attributable to maternal diabetes or coingestion of teratogens. The increase in preterm delivery 28% [calcium channel blockers] vs 9% [nonteratogenic controls], p=0.003), attributed to maternal disease by stepwise regression, was the most important factor responsible for the observed decrease in birth weight (mean -334 gm vs nonteratogenic controls, p=0.08).
  
  
  CONCLUSIONS
  This study suggests that calcium channel blockers do not represent a major teratogenic risk.
authors.affiliation: Motherisk Program, Division of Clinical Pharmacology/Toxicology, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: L A
authors.initials: LA
authors.lastname: Magee
authors.forename: B
authors.initials: B
authors.lastname: Schick
authors.forename: A E
authors.initials: AE
authors.lastname: Donnenfeld
authors.forename: S R
authors.initials: SR
authors.lastname: Sage
authors.forename: B
authors.initials: B
authors.lastname: Conover
authors.forename: L
authors.initials: L
authors.lastname: Cook
authors.forename: P R
authors.initials: PR
authors.lastname: McElhatton
authors.forename: M A
authors.initials: MA
authors.lastname: Schmidt
authors.forename: G
authors.initials: G
authors.lastname: Koren
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D000328:Adult; D001724:Birth Weight / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000009:adverse effects*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D012044:Regression Analysis
chemical_list: D002121:Calcium Channel Blockers