Evaluation of Hemodynamic Changes in Fetuses With Isolated Mild-to-Moderate Ventriculomegaly by Transabdominal Ultrasound

The Relationship Between Fetal Central Nervous System Malformations and Modified Myocardial Performance Index

INTRODUCTION

Fetal ventriculomegaly, the most commonly identified abnormality of the fetal central nervous system (CNS), has been associated with elevated levels of the modified myocardial performance index (mMPI). However, the impact of other CNS pathologies on mMPI has not yet been evaluated. This study aimed to investigate whether there were changes in the myocardial performance index of fetuses with CNS pathologies without congenital heart diseases.

METHODS

A total of 126 singleton pregnant women were included in this study. Sixty-three fetuses had fetal CNS abnormalities of acrania, anencephaly, encephalocele, Dandy-Walker malformation, hydrocephalus, and meningocele. The control group consisted of 63 healthy and gestational age-matched fetuses. All ultrasonographic examinations were done in the second trimester of gestation. The data related to the characteristics of pregnant women were evaluated, and fetal left ventricular mMPI was obtained by ultrasound scan.

RESULTS

The study and the control group participants were not significantly different by means of pregnancy characteristics. The mean mMPI was higher in the fetal CNS malformation group compared to the control groups (0.39±0.02 vs. 0.45±0.04, P<0.001). The mean mMPI value was similar for fetuses with both closed and open calvarium defects of fetal CNS malformation.

CONCLUSION

Fetal CNS anomalies may be associated with prenatal cardiac dysfunction. Moreover, this relationship might be independent of the type of fetal CNS malformation, whether a closed or open calvarium defect.

Brain Doppler abnormalities in fetuses with open spina bifida

BACKGROUND

To describe the brain Doppler changes in fetuses with isolated open spina bifida (OSB).

STUDY DESIGN

Doppler ultrasound measurements including the umbilical artery (UA) pulsatility index (PI), middle cerebral artery (MCA) PI, and their combination into the cerebroplacental ratio (CPR) and umbilicocerebral ratio (UCR) were performed in a cohort of fetuses with OSB. Included patients were individually matched to a control group without structural anomalies and similar gestational ages. MCA-PI and/or CPR values below the 5th centile were considered abnormal and indicative of cerebral blood redistribution, while UCR and UA-PI above the 95th centile were considered abnormal.

RESULTS

During the study period, 266 fetuses were recruited, 133 normally grown fetuses with OSB and 133 matched controls. Doppler recordings were successfully obtained in all fetuses at a median gestational age of 30.9 weeks. All cases showed UA-PI within normal ranges, but fetuses with OSB showed significantly higher frequency of cerebral blood redistribution (15.0 vs. 3.0%, p < .01), MCA-PI <5th centile (10.5% vs. 3.0%, p = .01), decreased CPR (9.8% vs. 2.3%, p = .01) and increased UCR (17.2 % vs 7.5 %, p =.02). The rate of cerebral blood redistribution was significantly higher in the OSB group with ventriculomegaly in comparison to those with OSB and normal lateral ventricle diameter (18.6% vs. 3.2%, respectively; p <.05).

CONCLUSION

A proportion of fetuses with isolated open spina bifida showed cerebral blood redistribution.

Estimating cerebral venous oxygenation in human fetuses with ventriculomegaly using quantitative susceptibility mapping

RATIONALE AND OBJECTIVES

The goal of this study was to estimate venous blood oxygen saturation (SvO2) in the superior sagittal sinus (SSS) in fetal brains with ventriculomegaly (VM) using quantitative susceptibility mapping (QSM).

MATERIALS AND METHODS

A radiofrequency spoiled gradient echo sequence was used to evaluate data on 19 fetuses with VM (gestational age(GA): median = 29.9 weeks (range 23 to 37.3 weeks)) and 20 healthy fetuses (GA: median = 30.9 (range 22.7 to 38.7 weeks)) at 1.5 T. Susceptibility weighted images encompassing the entire fetal brain were acquired within 1 min. An iterative, geometry constraint-based thresholded k-space division algorithm was used for generating QSM data of the fetal brain. The venous oxygen saturation was calculated using the magnetic susceptibility of the SSS obtained from the QSM data. Mixed-model analysis of variance and interobserver variability assessment were used to analyze the results.

RESULTS

The median SvO2 values in the entire VM cohort as well as for second and third trimester fetuses (with interquartile range) were: 67.8% (63.2%, 73.6%), 73.1% (69.1%, 77.3%) and 63.8% (59.4%, 68.1%), respectively. The corresponding median SvO2 value in the healthy control group was: 65.3% (58.3%, 68.2%), 67.5% (61.7%, 69.2%) and 60.8% (53.6%, 68.2%), respectively. However, the difference of SvO2 between VM and control groups was not significant at the p = 0.05 level (p = 0.076). The SvO2 was found decreasing significantly with GA in the healthy control group (p < 0.05).

CONCLUSIONS

We report for the first time the estimation of cerebral SvO2 in human fetuses with VM using QSM. This measure of oxygen saturation might be beneficial in assessing and monitoring the metabolic status of the fetus in various clinical conditions.