title: [Factors influencing the prognosis of patent ductus arteriosus in very low birth weight infants].
abstract: OBJECTIVE
  To investigate the factors influencing the prognosis of patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants.
  
  
  METHODS
  A total of 194 VLBW infants who were admitted from January 2012 to December 2014 were enrolled as study subjects. According to cardiac ultrasound findings and treatment outcome, these infants were divided into non-PDA group, spontaneous closure group, pharmaceutical closure group, and surgical closure group. Their clinical and echocardiographic characteristics were analyzed.
  
  
  RESULTS
  The spontaneous closure rate of PDA was 58.7%. The spontaneous closure group showed significantly higher gestational age, birth weight, and proportion of small-for-gestational-age infants than the pharmaceutical and surgical closure groups (P<0.05). The pharmaceutical and surgical closure groups had a significantly higher incidence rate of neonatal respiratory distress syndrome and a significantly higher proportion of infants who were given pulmonary surfactant (PS) than the spontaneous closure group (P<0.05). During different periods of time, the spontaneous closure group had a significantly smaller ductus arteriosus diameter than the pharmaceutical and surgical closure groups (P<0.05). The multivariate logistic regression analysis showed that gestational age, application of PS, and ductus arteriosus diameter at 48 hours were significantly associated with the prognosis of PDA. The major transductal flow pattern in the spontaneous closure group was closing pattern, while in the pharmaceutical and surgical closure groups, the main flow patterns were pulmonary hypertension and growing patterns within 48 hours and growing pattern on days 4 and 7.
  
  
  CONCLUSIONS
  The VLBW infants have a high spontaneous closure rate of PDA. A decreased closure rate of PDA is associated with the lower gestational age and the application of PS. PDA with a large ductus arteriosus diameter and a growing or pulsatile flow pattern cannot easily achieve spontaneous closure.
authors.affiliation: Department of Neonatal Intensive Care Unit, Children's Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China. dulizhong@yahoo.com.cn.
authors.forename: Chen-Hong
authors.initials: CH
authors.lastname: Wang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Shi
authors.forename: Xiao-Lu
authors.initials: XL
authors.lastname: Ma
authors.forename: Fang
authors.initials: F
authors.lastname: Luo
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.forename: Hui-Jia
authors.initials: HJ
authors.lastname: Lin
authors.forename: Li-Zhong
authors.initials: LZ
authors.lastname: DU
mesh_terms: D004374:Ductus Arteriosus, Patent / Q000503:physiopathology / Q000628:therapy*; D004452:Echocardiography; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008297:Male; D011379:Prognosis