1. Postgraduate Program in Health Science: Gynecology and Obstetrics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil, 90035-903
2. Department of Obstetrics and Gynecology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil, 90035-903
3. Clínica Mulher, Porto Alegre, Rio Grande do Sul, Brazil, 90570-060
4. Department of Obstetrics and Gynecology, Greenville Health System, Greenville, South Carolina