Magnetic Resonance Imaging in Pregnancy with Intrauterine Growth Restriction: A Pilot Study

Abstract EN

Objective.

Intrauterine growth restriction (IUGR) is a major cause of late stillbirth, though not all compromised babies remain small or are considered growth restricted as pregnancy progresses.

Fetal Magnetic Resonance Imaging (f-MRI) represents a second-line tool to study pregnancies with IUGR fetuses.

The aim of our study was to evaluate the usefulness of f-MRI on predicting fetal growth and the offspring’s perinatal respiratory outcome.

Design.

All f-MRI performed between 2014 and 2016 in Siena were analysed.

Pregnancies with IUGR (Study group (SG)) were recruited together with a control population (Control group (CG)), coupled for gestational age (GA) at the time of f-MRI (mean GA 31 wks).

Neonatal information was collected.

The f-MRI protocol consisted of T2w images.

Six regions of interest (ROI) were placed as follows: 2 on the lung, 2 on the liver, and 2 on the amniotic fluid.

The signal intensities (SI) of each ROI were measured.

The SI lung to liver ratio (SI lung/liver) and SI lung to amniotic fluid ratio (SI lung/amniotic fluid) were obtained for each fetus.

Each ratio was compared between SG and CG.

Therefore, SG was divided into two subgroups: adequate and small for gestational age (AGA and SGA) newborns.

All measurements were related to offspring’s perinatal respiratory outcome.

Results.

SI lung/liver was linearly related with GA at the time of f-MRI and with EFW.

SI lung/amniotic fluid was significantly higher in SG than in CG (p=0,014).

In contrast, among SG, lower values of SI lung/amniotic fluid were found in the SGA compared to AGA (p=0,036).

The days of oxygen supply were higher in the SGA subgroup than in the AGA subgroup (p=0,028).

Conclusions.

SI lung/liver increases with fetal lung maturation and appears to be useful to estimate intrauterine fetal growth.

SI lung/amniotic fluid seems to be a reliable predictive index to distinguish the IUGR fetuses that can recover their growth from those that were born SGA.

f-MRI represents a promising frontier to predict IUGR fetus outcome, thus contributing to ameliorate the perinatal management.