Citation

Redelmeier DA, Naqib F, Thiruchelvam D, Barrett JFR. BMJ Open 2016; 6(9): e011972.

Affiliation

Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.

Copyright

(Copyright © 2016, BMJ Publishing Group)

DOI

10.1136/bmjopen-2016-011972

PMID

27650764

Abstract

OBJECTIVES: To assess the incidence of cerebral palsy among children born to mothers who had their pregnancy complicated by a motor vehicle crash.

DESIGN: Retrospective longitudinal cohort analysis of children born from 1 April 2002 to 31 March 2012 in Ontario, Canada. PARTICIPANTS: Cases defined as pregnancies complicated by a motor vehicle crash and controls as remaining pregnancies with no crash. MAIN OUTCOME: Subsequent diagnosis of cerebral palsy by age 3 years.

RESULTS: A total of 1 325 660 newborns were analysed, of whom 7933 were involved in a motor vehicle crash during pregnancy. A total of 2328 were subsequently diagnosed with cerebral palsy, equal to an absolute risk of 1.8 per 1000 newborns. For the entire cohort, motor vehicle crashes correlated with a 29% increased risk of subsequent cerebral palsy that was not statistically significant (95% CI -16 to +110, p=0.274). The increased risk was only significant for those with preterm birth who showed an 89% increased risk of subsequent cerebral palsy associated with a motor vehicle crash (95% CI +7 to +266, p=0.037). No significant increase was apparent for those with a term delivery (95% CI -62 to +79, p=0.510). A propensity score-matched analysis of preterm births (n=4384) yielded a 138% increased relative risk of cerebral palsy associated with a motor vehicle crash (95% CI +27 to +349, p=0.007), equal to an absolute increase of about 10.9 additional cases per 1000 newborns (18.2 vs 7.3, p=0.010).

CONCLUSIONS: Motor vehicle crashes during pregnancy may be associated with an increased risk of cerebral palsy among the subgroup of cases with preterm birth. The increase highlights a specific role for traffic safety advice in prenatal care.

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Language: en