1. Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Francisco, 550 16th Street, San Francisco, California 94158, United States
2. Research, Development and Dissemination, Sutter Health, Walnut Creek, California 94596, United States
3. Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, California 94720, United States
4. Division of Epidemiology, School of Public Health, University of California, Berkeley, Berkeley, California 94720, United States
5. Department of Environmental Science, Policy, and Management & School of Public Health, University of California, Berkeley, Berkeley, California 94720, United States
6. Department of Civil and Environmental Engineering & School of Public Health, University of California, Berkeley, Berkeley, California 94720, United States
7. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California 94158, United States
8. Preterm Birth Initiative, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, California 94158, United States
9. Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032, United States