Funding for this research was provided by:
Shanghai Municipal Health Commission (201840217)
Clinical Science and Technology Innovation Program of Hospital Development Center (SHDC12018X10)
The fund for clinical study from Tongji Hospital (ITJ(ZD)1904)
the Fundamental Research Funds for the Central Universities of Tongji University (22120180355)
Received: 21 December 2019
Accepted: 24 March 2020
First Online: 4 June 2020
Ethics approval and consent to participate
: The Ethics Committee of Tongji Hospital, Tongji University School of Medicine declared that no formal ethics approval was required in this particular case. This study is a retrospective and observational study, and patient consent is not signed by each patient. All examination items were derived from routine prenatal care.
: Not applicable.
: The authors declare that they have no competing interests.