Institution: | a Reproductive Biomedicine Research & Training Unit Chemical Pathology Department College of Medicine University of Ibadan, Nigeria b Population Sciences Division Rockefeller Foundation 1133 Avenue of the Americas, New York, N.Y. 10036, U.S.A. c Department of Obstetrics & Gynecology Faculty of Medical Sciences UNICAMP, Campinas, S.P., Brazil d Department of Obstetrics & Gynecology Hospital Moscoso Pnello, Santo Domingo, Dominican Republic |