CJCP     2011 13 (10):  780-782    ISSN: 1008-8830  CN: 43-1301/R Perinatal conditions of preterm infants with different severities of respiratory distress syndrome XU Fa-Lin, ZHUANG Fang-Li, BAI Qiong-Dan, DUAN Jia-Jia Department of Neonatology, Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China. xufalin72@126.com Received: null  Revised: null  Online: null Supporting info