OC18.05: Neurodevelopmental outcome at 24‐months of full‐term small‐for‐gestational age infants with normal placental function

Objectives: To test the hypothesis of an association between brain sparing and fetal brain MRI texture analysis (TA) in small for gestational fetuses (SGA). Methods: 165 fetuses were recruited: 88 SGA with normal umbilical Doppler and 65 adequate for gestational age (AGA). Brain sparing was evaluated within ± 1 week from the MRI scan in three ways representing increasing degrees of this phenomenon: i) increased brain perfusion assessed with fractional moving blood volume (FMBV) in the frontal lobe (> 95th centile); ii) decreased cerebroplacental ratio (CPR) (< 5th centile); and iii) middle cerebral artery vasodilation (pulsatility index < 5th centile). All fetuses were imaged in a 3T MRI scanner at 37 weeks GA. Anatomical acquisitions were obtained in three planes. Manual delineation of 8 areas was carried out: bilaterally in frontal lobe, basal ganglia (BG)and peduncles and one area in cerebellum and cingulum. Right and left scores were averaged. All the delineated areas were processed with AQUA software to obtain their TA scores. To test our hypothesis, our sample was classified as 3 groups: AGA, SGA without brain sparing and SGA with brain sparing. This classification was performed for each of 3 criteria of brain sparing. The linear association across SGA groups with TA was performed by multivariate analysis of covariance with a polynomial contrast, adjusted for smoking, gender, BMI and GA at MRI. Results: In the SGA group, 15 cases had increased brain perfusion, 10 decreased CPR and 18 were vasodilated. We found significant linear changes of frontal, BG and peduncles TA scores across the different degrees of brain sparing based on FMBV (all P < 0.01), CPR (all P < 0.01) and MCA (all P < 0.01). Conclusions: Changes in fetal brain TA occur based on the severity of fetal growth restriction as defined by the signs of brain sparing. These findings support the knowledge that brain sparing in SGA fetuses is associated with an increasing degree of brain microstructural alterations.