1. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of California, Irvine, Orange County
2. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, University of California, Los Angeles, California
3. Department of Biomathematics, University of California, Los Angeles, California
4. Department of Anesthesia, University of California, Los Angeles, California
5. Department of Interventional Radiology; University of California, Los Angeles, California