1 Department of Obstetrics and Gynaeocology, School of Medicine, University of Zambia, Lusaka, Zambia; Department of Obstetrics and Gynaeocology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
2 Department of Obstetrics and Gynaeocology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; UNC Global Projects, Lusaka, Zambia.
3 Department of Obstetrics and Gynaeocology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
4 Department of Obstetrics and Gynaeocology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA. Electronic address: jeff_stringer@unc.edu.