Background: Nonright-handedness, particularly mixed-handedness, has been associated with a number of medical conditions. We examined whether handedness was associated with fecundity, measured by time to pregnancy.
Methods: We used data on parental handedness and time to pregnancy from 2 regional birth cohorts in Denmark: the Aalborg-Odense Birth Cohort (1984–1987) and the Aarhus Birth Cohort (1990–1992) (n = 5808 and 3426, respectively). We applied discrete-time survival analysis to assess fecundity in relation to handedness.
Results: In both cohorts, we saw a slightly lower fecundity in individuals who reported being mixed-handed.
Conclusions: Our data showed a modest association between mixed-handedness and subfecundity, which suggests that these traits may share a common etiology, perhaps tracing back to the prenatal period.
From the aDanish Epidemiology Science Centre, Department of Epidemiology, Institute of Public Health, University of Aarhus, Aarhus C, Denmark; bPerinatal Epidemiological Research Unit, Department of Gynaecology and Obstetrics, Aarhus University Hospital, Aarhus N, Denmark; cEpidemiology Branch, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health, Research Triangle Park, NC; dDepartment of Epidemiology, School of Public Health, UCLA, Los Angeles, CA.
Submitted 21 February 2008; accepted 29 April 2008; posted 2 December 2008.
Supported by a grant from the Danish Medical Research Council (No. 271-05-0115) and, in part, by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences.
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Correspondence: JL Zhu, The Danish Epidemiology Science Centre, University of Aarhus, Vennelyst Boulevard 6, DK 8000 Aarhus C, Denmark. E-mail: email@example.com.