Reading between the lines I am assuming that you don't actually want to find/meet your birth parents but just find out their medical histpry. If that is the case, the social worker/adoption agency that handled your adoption should be able to help you. Find out from your parents who handled your adoption and contact them. We adopted both our children and we were given background medical information by the social worker. But just be aware that the reports are often only as good as the person who wrote them and may not have all the information you want and may only have info on one bio parent. Good luck.

Hi there

Im not sure if you got any further with this but contact the social workers association they will be able to assist you otherwise you can contact the Registrar of Adoptions at the National Department of Social Development in Pretoria
Registrar of Adoptions, Department of Social Development
Private Bag X901, Pretoria, 0001
Tel: 012 312 7593
Fax. 012 323 3733