University of Colorado Denver, University of California, San Francisco (UCSF) - Department of Obstetrics, Gynecology & Reproductive Sciences, University of Washington - School of Medicine, affiliation not provided to SSRN, University of Washington - School of Medicine, University of California, Berkeley, University of California, San Francisco (UCSF) - Department of Epidemiology and Biostatistics, University of North Carolina (UNC) at Chapel Hill, Johns Hopkins University, University of Washington - School of Medicine, University of Washington - School of Medicine, University of Washington - School of Medicine, University of Washington - School of Medicine, University of Washington - School of Medicine, Kenya Medical Research Institute (KEMRI), Kenya Medical Research Institute (KEMRI) and Washington University in St. Louis