1. Department of Obstetrics and Gynecology, Greenville Health System, Greenville, SC, USA
2. Departmento de Ginecologia e Obstetrícia, Universidade Federal do Rio Grande do Sul, Brazil
3. Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, NC, USA
4. Department of Biology, Furman University, Greenville, SC, USA