Prenatal ultrasonic characteristic analysis of umbilical artery thrombosis / 中华超声影像学杂志

ABSTRACT

Objective:To investigate the prenatal ultrasonic characteristics and hemodynamic changes of umbilical artery (UA) thrombosis in fetus, and to improve the accuracy of prenatal ultrasound diagnosis.Methods:The prenatal sonographic features and hemodynamic index of 5 cases with umbilical artery thrombosis(UAT) in Chongqing Health Center for Women and Children from January 2018 to April 2020 were analyzed and summarized retrospectively.Results:The absence of blood flow in one of the two UA was found in the third trimester of pregnancy while two UA were displayed in previous ultrasound scans and the blood flow of the UA on the right side of the bladder disappeared in 5 cases. The umbilical cord cross section showed three cavities in 5 cases. The long axis section of the umbilical cord showed hyperecho in one UA with no blood flow in 4 cases, and no exact hyperecho in the UA only showed no blood flow in 1 case. The UA systolic/diastolic velocity ratio(S/D)<2.0 and UA pulsatility index (PI)<5 th were observed in 5 cases. The middle cerebral artery (MCA) PI<5 th in 4 cases and 10 th<MCA-PI<25 th in 1 case were observed. There was no abnormal cerebroplacental ratio (CPR) in 5 cases. One fetus died in utero as the pregnant woman refused to be hospitalized. The remaining 4 neonates had good outcomes. UAT was defined in 5 cases after delivery, 1 case with hypercoiled (over coiled) umbilical cord and another case with hypocoiled (under coiled) was found. There were no abnormalities in gross imagings of placenta in 5 cases. Pathological examination was performed in 4 cases, focal infarcts and calcifications were found in placental tissue, among which, subchorionic fibrin deposition and inflammatory cell infiltration were observed in 2 cases. Conclusions:UAT has characteristic prenatal sonographic features.In this study, S/D and PI measured in unobstructed UA has little effect on the assessment of fetal intrauterine condition during the formation of UAT, while MCA-PI has important clinical significance for the assessment of fetal intrauterine condition.