The use of intrauterine transfusions (IUTs), which is most often indicated for the treatment of hemolytic disease of the fetus and newborn (HDFN), has been associated with transient iron overload and resultant dose-dependent T1 signal intensity reduction in fetal spleens and livers, according to a recent study published in European Radiology.
IUTs, which are recognized as being a life-saving treatment for severe fetal anemia, have revolutionized the management of HDFN. With each IUT that is administered, however, iron bypasses uptake regulation via the placenta and then accumulates in fetal organs. The use of fetal magnetic resonance imaging (MRI) is able to noninvasively evaluate organ iron overload and/or fetal liver disease.
Read more about HDFN testing and diagnosis
The researchers of the current study included a total of eight fetuses who were undergoing IUTs and prenatal MRIs between 2014 and 2023 at an Austrian center. The fetuses were matched by gestational age (GA) with eight other fetuses who underwent fetal MRIs, but without IUTs, for different reasons.
Among the eight fetuses in the IUT cohort, five underwent IUTs for HDFN, two for intrauterine parvovirus B19 infection and one for twin-to-twin transfusion syndrome.
Results of the study revealed that those fetuses who received IUTs had statistically significantly larger volumes of both liver and spleen compared with the control cohort. Additionally, when compared with GA-matched controls, the fetuses who underwent IUT had numerically lower signal intensity (S1) on T1-weighted imaging data for both fetal livers and fetal spleens, although this difference was not statistically significant.
An inverse association was observed between T1 S1 and the number of IUTs (P =.099), which regressed with time (P =.057). Although T2 SI was not significantly associated with transfusion frequency, it did demonstrate a strong positive correlation with the number of days between an IUT and an MRI (P =.002).
Similar effects were observed regarding the following splenic SI measures:
- T1 SI reduction per IUT received: P =.167
- Recovery of T2 SI following IUT: P =.004
“This is the first study to report the effects of IUTs on MRI data of fetal livers and spleens,” the authors wrote. “Fetal hepatosplenomegaly can be expected following transfusions…Radiologists’ awareness of changes following IUT may improve report quality.”
