Abstract

Aim: to evaluate chronology of nephrogenic events in staged aborted human embryos and foetuses.
Materials and methods: The present study was the conducted in Department of Anatomy. Total 50 aborted embryos and dead foetuses of 5 weeks gestational age to full term were include in this study. The study was done in Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar, India, for 1 year. The entire specimens were preserved in formalin after recording the weight, CR length and CH length. Kidneys were removed from the foetuses of more than 8 weeks gestational age by opening the abdominal cavity. The specimens were subjected to routine tissue processing and H&E staining. 10 embryos of less than 8 weeks gestational age were processed as a whole and were serially sectioned. The histological sections were observed for the time of appearance of various nephrogenic components and photographed.
Results: Less than 12 weeks GA group: In this group a total of 8 embryos (less than 8 wks GA) and two fetuses were observed for renal histogenesis. 5 wks. Embryo: The youngest embryo observed in this group was that of 5 weeks GA with a CRL of 0.8 cms. In this embryo urogenital mesentery, degenerating pronephros and pronephric tubule could be identified. 6 wks. Embryo: In the 6 weeks GA (1.3 cms CRL) embryo urogenital mesentery containing developing mesonephric kidney and gonad were identified. 8 weeks embryo: At 8 weeks GA (1.6 cms CRL) differentiating renal corpuscles, proximal and distal convoluted tubules and collecting ducts could be identified. 12 weeks foetus: At 12 week (2.1 cms CRL, male foetus) mesonephric components could not be identified. 13-24 wks GA group: In this group a total of nine foetuses were observed for renal histogenesis. Sections from a specimen of 16 weeks and that of 24 weeks were compared for the developmental progression. During this period cortico-medullary differentiation was observed.
Conclusion: Detailed findings of this study could aid the embryologists, neonatologists and nephrologists to understand the chronology of nephrogenic events and related consequences of developmental abnormalities.