title: Pregnancy outcome following first-trimester exposure to zopiclone: a prospective controlled cohort study.
abstract: OBJECTIVE
  Zopiclone, a cyclopyrrolone derivative, is a short-acting hypnotic. To date, no published data exist regarding human pregnancy experience with zopiclone. The purpose of this study was to compare pregnancy outcome following first-trimester exposure to zopiclone with that of a matched control group of women, who were counseled for nonteratogenic exposure.
  
  
  METHODS
  The Motherisk Program, the Toronto Teratogen Information Service, prospectively collected and followed up 40 women exposed to zopiclone during pregnancy. Pregnancy outcome was compared with that of a matched control group of women, who were counseled for nonteratogenic exposure.
  
  
  RESULTS
  There was no increase in the rate of major malformations (0 of 31 [0%] for zopiclone vs. 1 of 37 [2.7%] for nonteratogenic controls; p = 1).
  
  
  CONCLUSIONS
  Our study, which is the first cohort on zopiclone use during embryogenesis, albeit small, suggests that zopiclone does not appear to be a major human teratogen. Larger studies are needed to establish its safety during pregnancy.
authors.affiliation: Department of Pediatrics, Research Institute, the Hospital for Sick Children and the University of Toronto, Ontario, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Diav-Citrin
authors.forename: B
authors.initials: B
authors.lastname: Okotore
authors.forename: K
authors.initials: K
authors.lastname: Lucarelli
authors.forename: G
authors.initials: G
authors.lastname: Koren
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology*; D000328:Adult; D053961:Azabicyclo Compounds; D016022:Case-Control Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007231:Infant, Newborn; D010879:Piperazines / Q000009:adverse effects*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D013723:Teratogens
chemical_list: D053961:Azabicyclo Compounds; D006993:Hypnotics and Sedatives; D010879:Piperazines; D013723:Teratogens; C515050:zopiclone