Hemodynamic changes and perinatal outcome associated with umbilical artery thrombosis: a retrospective study
Authors: Tu Peng , Zhang Xiaohang , Zhong Chunyan , Ran Qian , Ran Suzhen 
Published: March 2024

Abstract
Objective
Poor fetal and perinatal outcomes in fetuses associated with umbilical artery thrombosis (UAT), such as severe intrauterine growth restriction (IUGR) and intrauterine asphyxia have been reported by some case series. Its hemodynamic impact remains unclear. The aim of this study was to evaluate the hemodynamic changes and perinatal outcome in UAT fetuses with a relatively large sample.

Methods
We included singleton fetuses diagnosed with UAT and with at least one available Doppler evaluation before the end of pregnancy in our center from 2016 to 2023. Fetuses with structural abnormalities and with no follow-up results were excluded. Doppler waveforms from the Umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and uterine artery (UtA) were routinely evaluated according to ISUOG Practice Guidelines from diagnosis. The same sample of GA-matched normal fetuses with Doppler measurements during the same period were randomly selected as control group.

Results
Eighty-nine singleton fetuses with UAT with at least one Doppler evaluation before the end of pregnancy were identified, 13 fetuses with no follow-up results were excluded. After comprehensive prenatal counseling, 14 cases received urgent cesarean section, the remaining 55 cases received expectant management, the median day between GA at diagnosis and end of pregnancy was 13 (5–53) days (range, 2-159). 7 (7/76, 9.2%) cases occurred stillbirth, and the incidence of IUGR and Neonatal Intensive Care Unit (NICU) admission were 18.4% (14/76) and 13.2% (10/76) respectively. 49 fetuses (49/76, 64.5%) combined with Doppler abnormalities. UA abnormalities (35/76, 46.1%) and MCA abnormalities (34/76, 44.7%) were the most changes at presentation. Compared to control group, UA-EDV was significantly increased in UAT fetuses [21.84 (15.59–26.64) vs. 16.40 (12.43–20.70) cm/s, p < 0.001], UA-PI and UA-RI significantly decreased [0.68 (0.57–0.84) vs. 0.92 (0.79–1.11), p<0.001; 0.51 (0.44–0.59) vs. 0.62 (0.55–0.68), p < 0.001, respectively]. Both the MCA-PSV and MCA-EDV were significantly higher in UAT fetuses [54.60 (48.00-61.34) vs. 44.47 (29.66–57.60) cm/s, p < 0.001; 11.19 (7.84–17.60) vs. 8.22 (5.21-12.00) cm/s, p < 0.001, respectively], this led to a lower MCA-PI and MCA-RI. Meanwhile, DV-PIV was significantly higher in UAT fetuses [0.6 (0.47–0.87) vs. 0.45 (0.37–0.55), p < 0.001], CPR and UtA-PI were no significant difference between these two groups. Multivariate logistic regression analysis showed that DV-PIV was an independent risk factor for adverse pregnancy outcomes (OR 161.922, p<0.001), the area under the ROC curve (AUC) was 0.792 (95% CI 0.668–0.917; p < 0.001).

Conclusion
Our data showed serious adverse pregnancy consequences are combined with UAT fetuses. Hemodynamic changes in UAT fetuses showed the remaining artery for compensation and brain perfusion derangement. With a comprehensive and standardized Doppler evaluation, progression of fetal deterioration may be detailed presented.