Affiliation: | 1. Department of Obstetrics and Gynecology, Hospital Federal de Bonsucesso, Rio de Janeiro, Rio de Janeiro, Brazil;2. Obstetrics and Gynecology Department, Universidade Federal Fluminense, Niterói, Rio 3. de Janeiro, Brazil;4. Statistics Department, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil |