Funding for this research was provided by:
Research Program of Shanghai Sports Bureau (20Q001)
the National Key R & D Program of China (2018YFC1705300)
Received: 3 April 2020
Accepted: 2 October 2020
First Online: 8 October 2020
Ethics approval and consent to participate
: Songjiang Maternal and Child Health-care Hospital Institution Review Board authorized the ethic approval of this study (IRB#20171203), each mother and their children signed the informed consent papers ahead of the questionnaire interview.
: Not applicable.
: No competing interests.