[1] Linyi Maternal & Child Healthcare Hosp, Dept Obstet, 1 South Qinghe Rd, Linyi 276016, Shandong, Peoples R China
[2] Havy Int Shanghai Ltd, Bldg 25,1665 Kongjiang Rd, Shanghai 200092, Peoples R China
[3] Linyi Maternal & Child Healthcare Hosp, Dept Radiol, 1 South Qinghe Rd, Linyi 276016, Shandong, Peoples R China
[4] Linyi Maternal & Child Healthcare Hosp, Dept Ultrasound, 1 South Qinghe Rd, Linyi 276016, Shandong, Peoples R China
[5] Linyi Maternal & Child Healthcare Hosp, Dept Nursery, 1 South Qinghe Rd, Linyi 276016, Shandong, Peoples R China
[6] Linyi Maternal & Child Healthcare Hosp, Dept Pediat Cardiol, 1 South Qinghe Rd, Linyi 276016, Shandong, Peoples R China
[7] Harvard Med Sch, Beth Israel Deaconess Med Ctr, 330 Brookline Ave,Kirstein 3, Boston, MA 02215 USA