1. Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
2. International Center for Maternal and Newborn Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
3. Department of Maternal, Newborn, Child, Adolescent Health and Ageing, World Health Organization, Geneva, Switzerland
4. Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA