Frontal lobe development in fetuses with growth restriction by using ultrasound: a case–control study

BACKGROUND: Fetal growth restriction (FGR) occurs in up to 10% of pregnancies and is a leading cause of perinatal mortality and neonatal morbidity. Three-dimensional ultrasonography of intracranial structure volume revealed significant differences between fetuses with FGR and appropriate for gestational age (AGA) fetuses. We aimed to compare the frontal lobe development between fetuses with FGR and appropriately grown fetuses and evaluate the impact of fetal circulatory redistribution (FCR) on frontal lobe development in fetuses with FGR. METHODS: We performed a case–control study at our institution from August 2020 to April 2021. The frontal antero-posterior diameter (FAPD) and occipito-frontal diameter (OFD) were measured on the trans-ventricle view and we calculated the Z-scores for FAPD and OFD standardized for gestational age (GA) and transverse cerebellar diameter (TCD) by performing a standard regression analysis followed by weighted regression of absolute residual values in appropriately grown fetuses. We calculated the FAPD/OFD ratio as 100 × FAPD/OFD and FAPD/HC (head circumference) as 100 × FAPD/HC. To compare intracranial parameters, we randomly selected a control group of appropriately grown fetuses matched with the FGR group at the time of ultrasonography. We performed between-group comparisons of the FAPD Z-score, OFD Z-score, FAPD/OFD ratio and FAPD/HC. Similarly, we compared intracranial parameters between fetuses with FGR with and without FCR. RESULTS: FAPD/OFD ratio was curvilinear related to all the independent variables (GA, BPD, FL, and TCD). Compared with appropriately grown fetuses, fetuses with FGR showed a significantly lower FAPD/OFD ratio, FAPD Z-score, and FAPD/HC. There was no significant difference in the FAPD Z-score, FAPD/OFD ratio, and FAPD/HC between FGR fetuses with and without FCR. CONCLUSIONS: The FAPD/OFD ratio varied during pregnancy, with a mild reduction before and a mild increase after about 33 gestational weeks. Fetuses with FGR showed reduced frontal lobe growth; moreover, fetal frontal lobe development disorders were not significantly different in fetuses with FCR. TRIAL REGISTRATION: Date: 09–27-2017; Number: [2017]239.