Main findings
We found atypical brain morphology in fetuses with isolated CDH at 28 weeks of gestation, both on qualitative and quantitative scoring of different brain areas. By 33 weeks, the findings were less discrepant from those observed in normal fetuses. However, most fetuses (40/42, 95%) underwent FETO in between, hence severity of hypoplasia may be rather high and/or there may have been an effect of fetal surgery. We also found a significant increase in volume of extra-axial and ventricular fluid at 33 weeks of gestation in CDH.