1. 1Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, Utah.
2. 2Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, California.
3. 3Children’s Hospital at Westmead Clinical School, University of Sydney, Sydney, Australia.
4. 4Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California; and California Maternal Quality Care Collaborative, Stanford, California.
5. 5Department of Medicine, Stanford University School of Medicine, Stanford, California.
6. 6Department of Anesthesiology, Keck School of Medicine, University of Southern California, Los Angeles, California; Department of Anesthesiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
7. 7Department of Sociology, Texas A&M University, College Station, Texas.
8. 8Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, California.
9. 9Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, Stanford, California.