[1] Guangzhou Med Univ, Guangzhou Women & Childrens Med Ctr, Prenatal Diagnost Ctr, Guangzhou, Guangdong, Peoples R China
[2] Univ Richmond, Richmond, VA USA
[3] Guangzhou Med Univ, Guangzhou Women & Childrens Med Ctr, Prenatal Diagnost Ctr, Jinsui Rd 9,Zhujiang New Town, Guangzhou 510623, Guangdong, Peoples R China