OBJECTIVETo explore the risk factors of velamentous umbilical cord insertion(VCI)and the impact of VCI on perinatal outcomes.

METHODSThe clinical data of 588 VCI patients who were treated in Beijing Gynecology and Obstetrics Hospital from January 2006 to January 2011 were retrospectively analyzed. In addition,61,143 non-VCI subjects were enrolled as the control group. The possible risk factors of VCI and the impact of VCI on perinatal outcomes were analyzed. In addition,the causes of perinatal deaths were analyzed.

RESULTSThe gemellary pregnancy,multiple pregnancy,in vitro fitilization(IVF),placenta praevia,and placenta succenturiata/placenta bipartite were found to be the risk factors of VCI. The incidences of low birth weight,intrauterine growth restriction,asphyxia of newborns,deaths of fetuses or neonates,and single umbilical artery in the VCI group were significantly higher than those in the control group(all P<0.05). In 678 perineonates with VCI,the total death toll of perineonates was 7(1.0%),among whom the death causes included angiorrhexis of placenta praevia(n=1),preterm birth and low birth weight(n=3),torsion of cord(n=1),prolapse of cord(n=1),and placental abruption(n=1).

CONCLUSIONSThe risk factors of VCI should be carefully monitored. A diagnosis of VCI,if any,should be correctly made by using modern ultrasound techniques before delivery,so as to lower the mortality of perineonates.