[Li, Bo; Zou, Kehan; Xie, Donghua; Xiong, Lili] Maternal & Child Hlth Hosp Hunan Prov, Dept Hlth Management, Changsha, Peoples R China.
[Xie, Donghua] Hunan Prov Maternal & Child Hlth Care Hosp, NHC Key Lab Birth Defects Res & Prevent, Changsha, Hunan, Peoples R China.
[Wei, Jianhui] Cent South Univ, Xiangya Sch Publ Hlth, Changsha, Peoples R China.
[Zhu, Huiyuan] Univ South China, Sch Publ Hlth, Hengyang, Peoples R China.
[Peng, Xianglian] Maternal & Child Hlth Hosp Hunan Prov, Clin Med Res Ctr Maternal Neonatal Dis Hunan Prov, Changsha, Hunan, Peoples R China.