1. Department of Obstetrics and Gynecology Residency Program, Kaiser Permanente, Oakland, California
2. Division of Research, Kaiser Permanente, Oakland, California
3. Department of Graduate Medical Education, Kaiser Permanente, Oakland, California
4. Regional Perinatal Service Center, Kaiser Permanente Northern California, Regional Perinatal Service Center, Oakland, California
5. Department of Obstetrics and Gynecology, Kaiser Permanente—Eastbay, California