1. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology; Baylor College of Medicine and Texas Children's Hospital; Houston TX USA
2. Department of Obstetrics and Gynecology, Women's Health Hospital; Assiut University; Assiut Egypt
3. Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology; Baylor College of Medicine; Houston TX USA