title: First trimester exposure to anxiolytic and hypnotic drugs and the risks of major congenital anomalies: a United Kingdom population-based cohort study.
abstract: BACKGROUND
  Despite their widespread use the effects of taking benzodiazepines and non-benzodiazepine hypnotics during pregnancy on the risk of major congenital anomaly (MCA) are uncertain. The objectives were to estimate absolute and relative risks of MCAs in children exposed to specific anxiolytic and hypnotic drugs taken in the first trimester of pregnancy, compared with children of mothers with depression and/or anxiety but not treated with medication and children of mothers without diagnosed mental illness during pregnancy.
  
  
  METHODS
  We identified singleton children born to women aged 15-45 years between 1990 and 2010 from a large United Kingdom primary care database. We calculated absolute risks of MCAs for children with first trimester exposures of different anxiolytic and hypnotic drugs and used logistic regression with a generalised estimating equation to compare risks adjusted for year of childbirth, maternal age, smoking, body mass index, and socioeconomic status.
  
  
  RESULTS
  Overall MCA prevalence was 2.7% in 1,159 children of mothers prescribed diazepam, 2.9% in 379 children with temazepam, 2.5% in 406 children with zopiclone, and 2.7% in 19,193 children whose mothers had diagnosed depression and/or anxiety but no first trimester drug exposures. When compared with 2.7% in 351,785 children with no diagnosed depression/anxiety nor medication use, the adjusted odds ratios were 1.02 (99% confidence interval 0.63-1.64) for diazepam, 1.07 (0.49-2.37) for temazepam, 0.96 (0.42-2.20) for zopiclone and 1.27 (0.43-3.75) for other anxiolytic/hypnotic drugs and 1.01 (0.90-1.14) for un-medicated depression/anxiety. Risks of system-specific MCAs were generally similar in children exposed and not exposed to such medications.
  
  
  CONCLUSIONS
  We found no evidence for an increase in MCAs in children exposed to benzodiazepines and non-benzodiazepine hypnotics in the first trimester of pregnancy. These findings suggest that prescription of these drugs during early pregnancy may be safe in terms of MCA risk, but findings from other studies are required before safety can be confirmed.
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Lu
authors: L
authors: Ban
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Joe
authors: J
authors: West
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Jack E
authors: JE
authors: Gibson
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Linda
authors: L
authors: Fiaschi
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Rachel
authors: R
authors: Sokal
authors: Department of Non-communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors: Pat
authors: P
authors: Doyle
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Richard
authors: R
authors: Hubbard
authors: Department of Non-communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors: Liam
authors: L
authors: Smeeth
authors: Division of Epidemiology & Public Health, Nottingham City Hospital, University of Nottingham, Nottingham, United Kingdom.
authors: Laila J
authors: LJ
authors: Tata
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology* / Q000209:etiology; D000293:Adolescent; D000328:Adult; D014151:Anti-Anxiety Agents / Q000009:adverse effects*; D001007:Anxiety / Q000150:complications / Q000188:drug therapy*; D001569:Benzodiazepines / Q000009:adverse effects*; D002648:Child; D015331:Cohort Studies; D003863:Depression / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects*; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy*; D011261:Pregnancy Trimester, First; D011379:Prognosis; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
chemical_list: D014151:Anti-Anxiety Agents; D006993:Hypnotics and Sedatives; D001569:Benzodiazepines