The Application Value Of Color Doppler Ultrasound In Evaluation Of Fetal Intrapartum Hypoxia

Background Introduction:Fetal Intrapartum Hypoxia is one of major factors which cause fetal distress, neonatal asphyxia and perinatal death. Although, the hypoxia newnates can survive , they will suffer from nerve system disease, mental retardation and other disabilities in the future. The statistical data suggested that morbidity rate of newborn who had hypoxia intrapartum is 15%～18.2%. 25%～50% of them resulted from perinatal hypoxia. In China, there are about 300,000 disable neonates caused by intrapartum hypoxia every year. Therefore, it is critical to diagnosis fetal intrapartum hypoxia in early stage and prescribe effective treatment to decrease morbidity rate. In 1959, Scholander's research first time showed that there is the similar blood flow hemodynamic reaction mechanism between Fetal intrapartum hypoxia in human being and marine animal diving under water. Since then, many scholars studied the intrapartum hypoxia fetuses and drew the same conclusion by using this hypothesis. The Color Doppler Ultrasound provides convenient and effective method to study the blood flow hemodynamic reaction of fetal intrapartum hypoxia, which benefits to the monitoring, prediction and treatment of intrauterine hypoxia timely and precisely to improve the prognosis of the intrauterine hypoxia.Objective:To evaluate the application of Color Dopple ultrasound in monitoring neonatal hypoxia to provide evidence for the reduction of neonatal complication and improvement of the prognosis of fetal intrauterine hypoxia.Methods: Total of 92 pregnant women with gestation age 32-42 weeks were divided into two groups :60 cases were normal and 32 cases with hypoxia were diagnosed by clinical manifestation . All of them were examined by prenatal Color Dopple ultrasound .The hemodynamics parameters ,included Vs(systolic peak velocity),Vd(end diastolic velocity),Vs/ Vd,PI(pulsatility index) and RI(resistance index) of fetal UmA (umbilical artey), MCA (middle cerebral artery) and RA (renal artery)were measured , All data were collected .Results :(1 )The hemodynamics parameters of UmA of normal group were Vs: 43.18±9.17cm/s, Vd : 18.08±5.32cm/s, Vs/Vd: 2.12±0.42, PI: 0.80±0.13, RI: 0.56±0.15;and those of the hypoxia group were Vs: 42.03±10.02cm/s, Vd : 16.28±6.12 cm/s, Vs/Vd: 3.16±0.56, PI: 1.01±0.18, RI: 0.65±0.07. Comparing the two groups, we can obtained the indexes of the t are 0.55,1.47,10.05,6.43,0.96 respectively, There were significant differences among Vs/Vd of UmA, but the others were not.(2) The hemodynamics parameters of MCA of normal group were Vs : 51.72±14.47cm/s, Vd : 10.96±4.72 cm/s, Vs/Vd: 4.93±3.72, PI: 1.69±0.19, RI: 0.73±0.25 respectively; and those of the hypoxia group were Vs: 50.13±13.18cm/s, Vd : 9.76±5.32 cm/s, Vs/Vd: 4.01±2.76, PI: 1.44±0.22, RI: 0.65±0.24 respectively. From those data, we can calculate the indexes of the t are 0.52,1.11,1.23,5.69,1.48 respectively, There were significant differences among PI of MCA, but the others were not.(3) The hemodynamics parameters of RA of normal group were Vs: 38.89±8.26 cm/s, Vd : 5.13±1.61 cm/s, Vs/Vd: 5.12±1.65, PI: 1.82±0.24, RI: 0.74±0.22; and those of the hypoxia group were Vs: 27.62±7.33cm/s, Vd : 4.21±1.22 cm/s, Vs/Vd: 6.32±2.12, PI: 2.53±0.37, RI: 1.02±0.32. From above, we can generate the indexes of the t are 6.47,2.83,3.00,9.81,4.42 respectively, There were significant differences in all hemodynamics parameters of RA. (4) In this study, UmAVs/ Vd>3.0; RA RI>1.0; MCAPI/RAPK1.0 were selcted as limit to predict fetal hypoxia, the sensitivity were 67%, 79% and 75%, and the specificity were 96%,98%,and 96%. Combined with those three indexes, the sensitivity and the specility were 95% and 100%. Higher sensitivity and specificity were found if single index was exploited.Conclusions:There were significant differences in several hemodynamic parameters of MCA,UmA,RA between normal group and hypoxia group, especially in RI(p<0.01) in RA,Vs/ Vd(p<0.01)in UmA and MCAPI/RAPI(p<0.01). RA and RI together with UMA Vs/ Vd and MCAPI/RAPI were more valuable to detect fetal hypoxia.