About the Authors

Rita Patel

Affiliation School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom

Richard M. Martin

Affiliations School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom, Medical Research Council Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, United Kingdom

Michael S. Kramer

Affiliations Department of Pediatrics, McGill University Faculty of Medicine, Montreal, Canada, Department of Epidemiology and Biostatistics, McGill University Faculty of Medicine, Montreal, Canada

Emily Oken

Affiliation Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, United States of America

Natalia Bogdanovich

Affiliation The National Research and Applied Medicine Mother and Child Centre, Minsk, Belarus

Lidia Matush

Affiliation The National Research and Applied Medicine Mother and Child Centre, Minsk, Belarus

George Davey Smith

Affiliations School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom, Medical Research Council Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, United Kingdom

Debbie A. Lawlor

d.a.lawlor@bristol.ac.uk

Affiliations School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom, Medical Research Council Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: GDS DAL. Performed the experiments: MSK NB LM. Analyzed the data: RP DAL. Wrote the paper: DAL. Made critical comments on paper: RP RMM MSK EO NB LM GDS. Obtained funding for the study: RMM MSK EO.