1 Department of Family & Community Medicine, UCSF, San Francisco, CA; Department of Epidemiology & Biostatistics, UCSF, San Francisco, CA; UCSF Department of Obstetrics, Gynecology, & Reproductive Sciences, San Francisco, CA. Electronic address: [email protected].
2 Department of Family & Community Medicine, UCSF, San Francisco, CA. Electronic address: [email protected].
3 Department of Family & Community Medicine, UCSF, San Francisco, CA. Electronic address: [email protected].
4 UCSF Department of Obstetrics, Gynecology, & Reproductive Sciences, San Francisco, CA. Electronic address: [email protected].
5 Duke University Department of Family & Community Medicine, Durham, NC. Electronic address: [email protected].
6 UCSF Department of Obstetrics, Gynecology, & Reproductive Sciences, San Francisco, CA. Electronic address: [email protected].