1Departments of Medicine and Obstetrics and Gynecology, MedStar Georgetown University Hospital and Georgetown University Medical Center, Washington, DC, USA
2Department of Obstetrics and Gynecology, MedStar Georgetown University Hospital, Washington, DC, USA
3MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK
4Alan Turing Institute, London, UK
5National Osteoporosis Foundation, Arlington, VA, USA
6Department of Medicine, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA, USA