Xiamen University, Xiamen University, Quanzhou Maternity and Children’s Hospital, Putian University - Affiliated Hospital of Putian University, Fujian Medical University - Affiliated Longyan First Hospital, Ningde Maternity and Child Health Care Hospital, affiliation not provided to SSRN, Xiamen University, affiliation not provided to SSRN, Xiamen University, Xiamen University, affiliation not provided to SSRN and Xiamen University - School of Public Health