Clinical Study Of Ultrasonic Shear Wave Elastography In Assessing Placental Function In Patients With Hypertensive Disorders Of Pregnancy During Late Pregnancy

Objective The aim of this study is to investigate the value of ultrasonic shear wave elastography in assessing placental function in patients with gestational hypertension.Methods Late pregnancy women with placental maturity class II(30 cases in normal pregnancy group,22 cases in gestational hypertension group,and 29 cases in preeclampsia group)who were treated at the People’s Hospital of China Three Gorges University from December 2018 to January 2020 were randomly selected.We recorded the age,placental thickness,clinical gestational age,blood pressure,and proteinuria of these pregnant women.The ultrasound shear wave elastography technique was used to detect the placental Young’s modulus value.Spectrum Doppler was used to measure the fetal umbilical artery,Middle cerebral artery,uterine artery blood flow parameters of pregnant women.The fetal birth week,birth weight,1-minute and 5-minute Apgar scores were collected during the follow-up after the baby was born.Compared the difference in Young’s modulus of placenta and related parameters between the normal pregnancy group and the gestational hypertension group,and calculate the cut-off value of placenta Young’s modulus for the diagnosis of gestational hypertension.Then,compared the difference in Young’s modulus of placenta and related parameters between the normal pregnancy group and the preeclampsia group,and calculate the cut-off value of placenta Young’s modulus for the diagnosis of preeclampsia.Finally,correlation analysis of placental Young’s modulus value with blood flow parameters of umbilical artery,middle cerebral artery,uterine artery,and1-minute and 5-minute fetal Apgar scores were respectively conducted.Results The normal group was 21-36(28.97 ± 3.94)years old,and the gestational age was 30.9-38.9(36.83 ± 2.46)weeks.The gestational hypertension group was 26-41(30.95 ± 4.19)years old and the gestational age was 31.3-40(37.78 ± 1.47)Week;The preeclampsia group was 24-41(29.59 ± 5.67)years old,gestational age was 30.0-39.6(35.61 ± 2.43)weeks;There was no difference between the groups.Parameters of fetal umbilical artery blood flow PI(0.78 ± 0.15 vs 0.79 ± 0.13),RI(0.53 ± 0.07 vs 0.55± 0.06),S / D(2.17 ± 0.34 vs.2.22 ± 0.25)And middle cerebral artery blood flow parameters PI(1.43 ± 0.25vs1.56 ± 0.28),RI(0.76 ± 0.05vs0.78 ± 0.05),S/D(4.32 ± 1.33 vs 4.98 ± 1.77)had no significant difference between the gestational hypertension group and the normal control group(P> 0.05).There were differences in PSV(64.34 ± 7.70 vs 56.76 ± 10.93)of middle cerebral artery blood flow between thegestational hypertension group and the normal control group(P<0.05).Parameters of uterine arterial blood flow PI(0.84 ± 0.37 vs 0.66 ± 0.22),RI(0.52 ± 0.12 vs 0.46± 0.07),S / D(2.26 ± 0.77 vs 1.90 ± 0.29))have significant differences between the gestational hypertension group and the normal control group(P<0.01).The umbilical artery PI(1.05 ± 0.37 vs 0.79 ± 0.13),RI(0.64 ± 0.12 vs 0.55 ± 0.06),S/D(3.40 ±2.24 vs2.22 ± 0.25)of preeclampsia group and normal control group fetus were significant different(P<0.01).The Middle cerebral artery PSV(62.27 ± 9.78 vs 56.76± 10.93)of preeclampsia group and normal control group fetus were different(P <0.05).There were no statistical difference in fetal middle cerebral artery PI(1.45 ± 0.41 vs 1.56 ± 0.28),RI(0.77 ± 0.06 vs 0.78 ± 0.05),and S/D(4.46 ± 1.74 vs 4.98 ±1.77)between the preeclampsia group and the normal control group(P>0.05).The parameters of uterine arterial blood flow PI(0.97 ± 0.42 vs 0.66 ± 0.22),RI(0.61 ±0.15 vs 0.46 ± 0.07),and S / D(3.03 ± 1.41 vs 1.90 ± 0.29)were significant different in the preeclampsia group and the normal control group(P<0.01).The placental Young’s modulus of the normal pregnancy group was(2.98±0.82)k Pa,the placental Young’s modulus of the gestational hypertension group was(4.82±0.75)k Pa,and the placental Young’s modulus of the pre-eclampsia group was(5.40±1.28)k Pa.The placental Young’s modulus value of the diseased group(gestational hypertension group and pre-eclampsia group)was significantly higher than that of the normal control group(P<0.01).The placental Young’s modulus value of the pre-eclampsia group was significantly higher than that of the gestational hypertension group(P<0.01).Taking 3.59 k Pa as the cut-off value of the placental Young’s modulus to diagnosis the gestational hypertension,the sensitivity is 95% and the specificity is 77%.The ROC curve has an AUC of 0.941.Taking 4.12 k Pa as the cut-off value of the placental Young’s modulus to diagnosis the preeclampsia,the sensitivity is 86%,the specificity is 93%.The area under the ROC curve was 0.951.There is some correlation between the Young’s modulus of the placenta and the RI of uterine artery blood flow(r = 0.308),and has no obvious correlation with the uterine artery blood flow parameter PI,S/D(r is 0.234,0.256,respectively).There is no obvious correlation between the Young’s modulus of the placenta and the partial blood flow parameters PI,RI,S/D of fetal umbilical artery(r is 0.255,0.290,0.168,respectively).The correlation between placental Young’s modulus and fetal middle cerebral artery blood flow parameters PI,RI,S/D,PSV(r was-0.161,0.122,-0.092,0.148respectively)were not significant.There is no correlation between the Young’s modulus ofthe placenta and Apgar scores(1minute and 5minute,r were-0.069、-0.081 respectively).Conclusion Compared with the classification of placental maturity,the Young’s modulus of placenta detected by ultrasonic shear wave elastography can quantitatively analyze the hardness of the placenta,can more objectively reflect the placental function,and provides a new method for the diagnosis of hypertension during pregnancy.