Middle Cerebral Artery Peak Systolic Velocity in Fetuses With Transposition of the Great Arteries.

OBJECTIVE

To examine peak systolic velocity in the middle cerebral artery (MCA-PSV) in fetuses with transposition of the great arteries (TGA) and evaluate if TGA is associated with fetal anemia.

METHOD: A retrospective, exploratory study with inclusion of singleton fetuses born with TGA at Copenhagen University Hospital Rigshospitalet 2016-2023. Data on MCA-PSV, neonatal hemoglobin and specific diagnoses were manually retrieved from patient files.

RESULTS

In 52 cases, 205 MCA-PSV measurements from GA 20 + 0 to 39 + 1 met the inclusion criteria. Overall median MCA-PSV MoM was 1.09 (IQR 0.96; 1.20), increasing from 0.97 (IQR 0.86; 1.15) at gestational week 20 + 0 to 24 + 6 to 1.13 (IQR 0.95; 1.19) at gestational week 35 + 0 to 39 + 1. There were no differences in MCA-PSV MoM between cases with and without surgical closure of a VSD. Median hemoglobin concentration was 16.4 g/dL (IQR 15.3-17.2 g/dL) and MCA-PSV was inversely correlated with hemoglobin (-4.81 [95% confidence interval -7.21; -2.41]).

CONCLUSION

The study adds to the limited evidence on MCA-PSV in TGA fetuses, supporting a trend of increasing MCA-PSV MoM with gestational age, although not significant after accounting for multiple measurements. Higher MCA-PSV MoM correlated with lower neonatal hemoglobin. However, findings do not show that TGA fetuses have elevated MCA-PSV due to anemia or that VSD influences MCA-PSV levels.