1. Department of Human Ecology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, California, USA.
2. California Preterm Birth Initiative, School of Medicine, University of California, San Francisco, San Francisco, California, USA.
3. Department of Family Health Care Nursing, School of Nursing, University of California, San Francisco, San Francisco, California, USA.
4. Department of Social and Behavioral Sciences, School of Nursing, University of California, San Francisco, San Francisco, California, USA.
5. Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Francisco, San Francisco, California, USA.
6. Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, California, USA.
7. Department of Humanities and Social Sciences, University of California, San Francisco, San Francisco, California, USA.
8. Medicines360, San Francisco, California, USA.