Is fetal middle cerebral artery peak systolic velocity correlated with hemoglobin levels in cases of nonimmune fetal anemia?

Abstract

Objectives

To establish whether a correlation exists between the fetal middle cerebral artery peak systolic velocity (MCA PSV) and fetal hemoglobin levels before intrauterine transfusion (IUT) in cases of severe fetal anemia.

Methods

This was a single-center, retrospective study of data from 49 fetuses treated with IUT for fetal anemia between 2003 and 2018. Severe fetal anemia was suspected when MCA PSV was or exceeded 1.55 multiples of the median.

Results

The causes of anemia were largely idiopathic, and the overall survival rate was 57%. MCA PSV and hemoglobin were correlated in all 34 fetuses with alloimmune fetal anemia, whereas the 15 fetuses with nonimmune causes showed no correlation. Of the 15 noncorrelated cases, twin pregnancy was most common, followed by idiopathic causes. All the twin pregnancies involved monochorionic twins. Fetal hydrops, especially ascites, was significantly associated with severe anemia.

Conclusions

Fetal MCA PSV may not be a reliable independent factor for the diagnosis of severe fetal anemia in nonimmune cases, and the presence of associated hydrops implies that the fetus is more likely to have severe fetal anemia than in a fetus without hydrops.

Keywords:

• Anemia
• cordocentesis
• cord blood sampling
• fetal therapies
• fetal transfusion
• intrauterine transfusion
• middle cerebral artery

Authors contribution

Mi-Young Lee and Hye-Sung Won designed and directed this study. Joohee Lee and Mi-Young Lee wrote the manuscript. Won-Kyu Jang, So-Hyun Nam, Sang-Hee Jeong, and Heehwa Choi analyzed the data. All authors provided critical feedback and helped shape the research, analysis, and manuscript.

Disclosure statement

The authors have no conflicts of interest to declare.