1 Department of Obstetrics and Gynecology, Medical School of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil.
2 Department of Obstetrics and Gynecology, Medical School of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil School of Health Technology, Ultrasonography School of Ribeirao Preto (FATESA-EURP), Ribeirao Preto, Brazil wpmartins@gmail.com.