BMJ Open 2:e001185 doi:10.1136/bmjopen-2012-001185
  • Pharmacology and therapeutics
    • Research

β-Blocker treatment during pregnancy and adverse pregnancy outcomes: a nationwide population-based cohort study

  1. Henrik Enghusen Poulsen1
  1. 1Department of Clinical Pharmacology, Q, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
  2. 2Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
  3. 3Department of Cardiology, Gentofte Hospital, Gentofte, Denmark
  1. Correspondence to Kasper Meidahl Petersen; kaspermeidahl{at}
  • Received 20 March 2012
  • Accepted 27 June 2012
  • Published 19 July 2012


Objective To investigate the association between exposure to β-blockers during pregnancy and the risk of being born small for gestational age (SGA), preterm birth and perinatal mortality in a nationwide cohort.

Design A population-based retrospective cohort study, using the Danish Fertility Database. The authors identified all pregnant women redeeming a prescription for β-blockers using the National Prescription Registry. Multivariate logistic regression models were used to assess the association between exposure and our outcomes.

Setting Register-based survey.

Participants 911'685 births between 1995 and 2008 obtained from the Danish Fertility Database.

Outcome measures Being born SGA was defined as having a birth weight below the 10th percentile for the corresponding gestational week. Preterm birth was defined as birth before the 37th gestational week. Perinatal mortality was defined as either death occurring within the first 28 days of life or stillbirth. Before 2004, fetal deaths were recorded as stillbirths if they occurred after 28 weeks of gestation, but since then stillbirth is recorded for deaths after 22 gestational weeks.

Results The authors identified 2459 pregnancies exposed to β-blockers. β-Blocker exposure during pregnancy was found to be associated with increased risk of SGA (adjusted OR 1.97, 95% CI 1.75 to 2.23), preterm birth (adjusted OR 2.26, 95% CI 2.03 to 2.52) and perinatal mortality (adjusted OR 1.89, 95% CI 1.25 to 2.84). Analyses were adjusted for socioeconomic and maternal variables. The authors found similar risk profiles for pregnancies exposed to labetalol and for pregnancies exposed to other β-blockers.

Conclusions The authors found that exposure to β-blockers during pregnancy was associated with being born SGA, preterm birth and perinatal mortality. Our findings show that labetalol is not safer than other β-blockers during pregnancy.


  • To cite: Meidahl Petersen K, Jimenez-Solem E, Andersen JT, et al. β-Blocker treatment during pregnancy and adverse pregnancy outcomes: a nationwide population-based cohort study. BMJ Open 2012;2:e001185. doi:10.1136/bmjopen-2012-001185

  • Contributors KMP, EJ-S, JTA and HEP conceptualised the study. MP, KB, LK and CT-P assisted with the study design. KMP preformed the analyses assisted by EJ-S, and JTA, MP, KB, LK, CT-P and HEP assisted in the interpretation. KMP, EJ-S, JTA, MP, KB, LK, CT-P and HEP wrote and revised the final manuscript. Figure design was done by KMP, EJ-S, JTA, MP, KB, LK, CT-P and HEP. All authors approved the final version to be published.

  • Funding The project was sponsored by the Capital Region of Copenhagen.

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement The original manuscript submitted includes all available data. No additional unpublished data are available.

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