1. Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine; Baylor College of Medicine; Houston TX USA
2. Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility; University of North Carolina; Chapel Hill NC USA
3. Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine; Baylor College of Medicine and Texas Children's Hospital; Houston TX USA