We used the WHO MultiCountry Survey on Maternal and Newborn Health (WHOMCS) to create our reference population. Detailed description of this study has been published elsewhere.21 Briefly, the WHO MCS was a cross-sectional study implemented in 359 health facilities in 29 countries. Countries, provinces (or other equivalent political divisions within countries), and health facilities were randomly selected to participate in the WHO MCS through a stratified, multistage cluster sampling strategy. Health facilities were only eligible if they dealt with