1. Head Department of Physiology, Red Sea University, Sudan
2. Departmemt of Obstetrics and Gynecology, Ribat University Hospital, Khartoum, Sudan
3. Head Department of Physiology, The National Ribat University, Khartoum, Sudan
4. Department of Statistic and Population study, Red Sea University, Port Sudan, Sudan
5. Faculty of Medicine, The National Ribat University, Sudan