Funding for this research was provided by:
National Institute of Environmental Health Sciences (K99ES027023, P01ES022841, R01ES027051)
University of California San Francisco, Preterm Birth Initiative
U.S. Environmental Protection Agency (RD-83543301)
Received: 3 March 2018
Accepted: 24 April 2018
First Online: 2 May 2018
Ethics approval and consent to participate
: The State of California, Committee for the Protection of Humans Subjects and the Committee for Protection of Humans Subjects at the University of California, Berkeley approved this study (Protocol # 2013–10-5693).
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.