[1] Emory Univ, Atlanta, GA 30322 USA
[2] Childrens Healthcare Atlanta, Atlanta, GA 30329 USA
[3] Rollins Sch Publ Hlth, Atlanta, GA 30322 USA
[4] Univ Witwatersrand, Fac Hlth Sci, Sch Obstet & Gynecol, MRU MatCH Res Unit, Durban, South Africa
[5] Adv Access & Delivery, Durban, South Africa
[6] Univ N Carolina, Gillings Sch Global Publ Hlth, Dept Hlth Behav, Chapel Hill, NC USA
[7] Human Sci Res Council, Ctr Community Based Res, Pietermaritzburg, South Africa