Affiliation: | (1) Danish Epidemiology Science Centre, University of Aarhus, Aarhus, Denmark;(2) Shanghai Institute of Planned Parenthood Research, Shanghai, P.R. China;(3) Department of Epidemiology and Social Medicine, University of Aarhus, Aarhus, Denmark;(4) Department of Clinical Epidemiology, Aarhus University Hospital and Aalborg Hospital, Aarhus, Denmark |