1. Department of Social Medicine, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo Brazil
2. Institute of Mathematical Science and Computing, University of São Paulo, São Carlos, Brazil
3. Department of Portfolio Risk Management and Provisioning, Brasília Caixa Econômica Federal, Brazil
4. Department of Obstetrics and Gynaecology, College of Medicine, University of Ibadan, Ibadan, Nigeria
5. Department of Obstetrics and Gynaecology, Mother and Child Hospital, Akure, Ondo State, Nigeria
6. Department of Obstetrics and Gynaecology, Mother and Child Hospital, Ondo, Ondo State, Nigeria
7. General Hospital, Kubwa, Abuja, Nigeria