1 Department of Obstetrics and Gynaecology, Modilon General Hospital, PO Box 1200, Madang 511, Papua New Guinea. Electronic address: johnbolnga@gmail.com.
2 Department of Obstetrics and Gynaecology, Modilon General Hospital, PO Box 1200, Madang 511, Papua New Guinea.
3 Department of Paediatrics, Modilon General Hospital, PO Box 1200, Madang 511, Papua New Guinea.
4 Department of Paediatrics, Modilon General Hospital, PO Box 1200, Madang 511, Papua New Guinea; Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.