Funding for this research was provided by:
Japan Society for the Promotion of Science (JP 26670982)
Received: 22 April 2020
Accepted: 8 July 2020
First Online: 29 July 2020
Ethics approval and consent to participate
: The Institutional Review Boards of all participating institutes approved the study, and written informed consent was obtained from all participating mothers. The Research Ethics Committee of the Faculty of Medicine of the University of Tokyo, and the Kyushu University Institutional Review Board for Clinical Research approved the study.
: Not applicable.
: The authors have no competing interests to report.