1 Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco School of Medicine, 480 16 St., 10th Floor, Box 0132, San Francisco, CA 94143-0132. Electronic address: [email protected].
2 Institute for Family Health, New York, NY.
3 Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Francisco School of Medicine, San Francisco, CA.
4 Department of Obstetrics and Gynecology, University of Texas Rio Grande Valley, Edinburg, TX.