Analysis Of Clinical High-risk Factors For Vasa Previa And Pregnancy Outcomes

Objective:The purpose of the study was to investigate the diagnostic and management strategies for vasa previa and describe the clinical high-risk factors that may aid in the screening protocol to improve the perinatal outcome.Methods:This was a retrospective review of all identified vasa previa cases from January 1 2006,to December 31 2016 in the Department of Obstertrics and Gynecology,the 1st Affiliated Hospital of Kunming Medical University.Data on obstetrical history,modes of conception,sonographic scans,delivery mode,and neonatal outcomes were retrieved and recorded.Results:1、We encountered 36 cases of vasa previa among 43730 deliveries(overall incidence of 8/10000 deliveries).23 cases(63.89%)were diagnosed by ultrasound scanning antenatally at a median gestational age of 33.57(range:17-38.4)weeks.Known risk factors for vasa previa were present in 34 of 36 cases(94.45%).The 2 major risk for vasa previa are velamentous umnilical cord insertion,marginalcord insertion(61.12%)and bilobed,sucenturiate lobed placenta(25%).Approximately 44.45%of cases had a marginal placental previa or low lying placenta.In addition,another risk factor is In vitro fertilization(2.78%).2、In cases without prenatal diagnosis,there was a higher proportion of fetal vessels rupture and neonates with 5-minute Apgar score ≤7 and perinatal mortality compared with cases diagnosed prenatally(30.77%versus 0%,P<0.05,and 38.46%versus 0%,P<0.05,and 46.15%versus 4.35%,P<0.05,respectively).The comparition of proportion of preterm delivery and respiratory complication are(47.385%versus15.38%,p>0.05)and(17.39%versus 20%,p>0.05),considered statistically nonsignificant.3、In cases emergent cesarean,there was a higher proportion of fetal vessels rupture and neonates with 5-minute Apgar score ≤7 and perinatal mortality compared with cases diagnosed prenatally(33.33%versus 0%,P<0.05,and 33.33%versus 0%,P<0.05,and 44.44%versus 7.69%,P<0.05 respectively).4、Of the 36 cases 27 were delivered by nonemergent cesarean or vaginal delivery at a mean gestational age of 37.83±2.17 weeks,and 9 cases required emergent cesarean delivery at a median gestational age of 34.71(range:33.29-40.86)weeks.5 cases of these 9 emergent cesarean deliveries had been diagnosed previously;4 cases had not.5 cases of emergent cesarean deliveries were for vaginal bleeding,4 cases were for concerning fatal heart rate,3 cases had documented ruputured fetal vessels.There are 3 cases of neonatal deaths.Another 2 neonates had undergone blood transfusions.5、The prenatal detection rate of vasa previa from 43.75%to 80%between the 2 time periods(P<0.05),whereas perinal mortality and 5-minute Apgar score ≤7 decreased from 25%to 15%and from 18.75%to 10%,although not significantly(P>0.05).Conclusions:Prenatal sonographic screening using targeted scans for vase previa in all pregnant women as part of routine mid-gestation scanning,especillay for whom with risk factors and deliver before rupture of membranes or labor may significantly impact its obstetric manifestations.