The Alteration Of Umbilical Artery Flow Velocimetry When The Fetal Heart Rate Is Abnormal During Labor

Cardiotocography (CTG) is a common intrapartum fetal monitoring method, it reflects fetal central nervous system condition through kinds of different fetal heart rate wave forms. It has a high sensitivity and a high false positive predictive value. The Color Doppler Ultrasonic Umbilical Artery Analysis is a method to detect the circulation of placent. It is no injury, and can reflect the resistance of placent by examining S/D (systolic to diastolic ratio) of umbilical artery.Whether it can be used in fetal monitoring, there are still not insure, needing more research. while, how the umbilical artery flow velocimetry changed when the CTG shows various kinds of abnormal wave forms, up to now, there is no report in this aspect.Objective:To investigate how the umbilical artery flow velocimetry changed when the intrapartum CTG shows abnormal wave forms.To analyse the relationship between the abnormal S/D and fetal distress. To eveluate whether the combination of the two methods can elevate the diagnosis level of fetal distress.Methods: Total 72 pregnant women deliverd in Dalian Obstetrics and Gyneoloe Hspital during 2003.6~2003.12 are observed. They are singleton pregnancy, head engagement, full pregnant days, have no other diseases and not using narcotic, cervix dilated in 3~8cm. During labour, they are under the Cardiotocography (CTG) mornitoring. The women whose CTG show abnormal wave forms are devided into two groups: the late deceleration group (LD group) 12 women(everage age 28±2.5 years, everage pregnant age 38±0.5 weeks)and the severe variable deceleration group (SVD group) 20 women ( everage age 27±5.4 years, everage pregnant age 38±0.5 weeks ). Other 40 women with normal wave forms are controls ( everage age 28±3.6 years, everage pregnant age 38±0.8 weeks ). The blood flow of umbilical artery (S/D) were examined in all the women by Color Doppler Ultrasonic instrument during contraction and intermission respectively. After delivery ,determining whether the fetal has an adverse pregnancy outcome, as judged by the low Apgar scores, meconium, cesarean section for fetal distress and acidosis (umbilical blood gas analysis PH<7.20). Using SPSS statistic system to analyse the datum. Results: 1.In LD group, the contraction and intermission S/D are obviously higher than the control group , while there are no difference between the SVD group and control group.2.The fetal distress rate in LD group and SVD group are obviously higher than control group.3.In LD group , the abnormal higher contraction and intermission S/D correlate with the fetal distress .while in SVD group and control group are not .4.In LD group, using the contraction and intermission S/D to eveluate the fetal distress are same , the sensitivity ,specificity , positive predictive value and negative predictive value are 90.00%, 100%, 100%, 66.70% respectively. Except the negative predictive value, other rates are higer than the rates using single CTG or S/D to predict fetal distress.Conclusion: When the intrapartum CTG shows LD, the S/D of umbilical blood flow will higher than normal. The combination of the two methods can elevate the diagnosis level of fetal distress. The umbilical artery analysis can't be a screening test to predict the fetus distress, it only can be used as an accessory method of CTG in special people.