1. Department of Obstetrics and Gynecology (L.C.K., A.G., S.T., S.L., J.P.Y., L.C.G.), Stanford University, Stanford, California 94305
2. Department of Obstetrics, Gynecology, and Reproductive Sciences (R.N.T.), University of California, San Francisco, California 94143
3. Department of Obstetrics & Gynecology (K.O.), Vanderbilt University, Nashville, Tennessee 37232
4. Department of Obstetrics & Gynecology (B.A.L.), University of North Carolina, Chapel Hill, North Carolina 27599