1. Department of Obstetrics and Gynecology; Baylor College of Medicine; Texas Children's Fetal Center; Houston TX USA
2. Department of Obstetrics and Gynecology; Mayo Clinic College of Medicine; Rochester MN USA
3. Department of Neurosurgery; Baylor College of Medicine; Texas Children's Fetal Center; Houston TX USA
4. Department of Obstetrics and Gynaecology; Women's Health Hospital; Assiut University; Assiut Egypt