The Corticomedullary Differentiation (CMD) of the kidneys, as well as the timing of its appearance and modifications during the prenatal period, is precisely defined. It is described as having a cortex that is comparatively more hyperechoic than the medulla. It is seen starting at 15 weeks, and as the foetus becomes older, it becomes more noticeable. A prelude to an underlying foetal renal pathology is the loss, rise, or reversal of CMD.

Many different aetiologies, including glomerulonephritis, acute tubular necrosis, end-stage chronic renal failure, obstructive hydronephrosis, Fabry's disease, and acute allograft rejection, might cause loss of CMD subsequent to them. Loss of corticomedullary differentiation and increased cortical echogenicity during pregnancy may be important indicators of future renal function. We report prenatally on the loss of cortico-medullary differentiation in both kidneys at 28 weeks of pregnancy and at 34 weeks of gestation, and confirmed by postnatal ultrasound. Both kidneys are postnatally and antenatally normal in size and shape. The baby's NCCT scan and the PET SPECT research showed that both kidneys' renal function had decreased. Our case is likely the first to describe the loss of CMD during pregnancy and the loss of renal function when the Glomerular Filtration Rate (GFR) falls below the 60 mL/min/1.73 m2 threshold, which is recognized as a disease regardless of age.

Ashutosh Gupta has completed his DM in Medical Genetics (2009), MS in OBGYN (2005) at the age of 34 years from Sanjay Gandhi Post Graduate Institute of Medical Sciences, SGPGIMS Lucknow, India. He is the head of the Department of Fetal Medicine & Medical Genetics and Clinical Co-ordinator for Foetal Medicine Fellowship Programme at Artemis Hospital for the last 10 years. He has numerous publications and has been serving as an editorial board member of a few reputed journals.