Kidney surface development in human fetuses: study applied to radiological diagnosis

OBJECTIVE: To evaluate the anatomical aspects of the kidney surface in human fetuses during the second gestational trimester. MATERIAL AND METHODS: We studied 108 kidneys obtained from 54 human fetuses (29 males and 25 females). The kidney was dissected and the number of clefts was counted. The renal volume was also assessed. To compare the quantitative data in both sexes, the Students-t-test was used (p < 0.05). Simple linear correlations were calculated for all kidney measurements, according to fetal age. Statistical analysis was performed with the R program (Version 3.5.1). RESULTS: The fetuses ranged in age between 11.4 to 23 weeks post-conception. The renal volume of the right kidney ranged from 0.09 to 2.397 cm (mean=0.8479) and the renal volume of the left kidney ranged from 0.07 to 2.416 cm (mean=0.8036). The mean number of renal clefts in fetuses studied was 15.25 (7 to 28). There was no statistical significant difference in renal clefts between the sides either in males (p = 0.646) or in females (p = 0.698). Also, there was no significant difference in the mean number of renal clefts between male and female fetuses in right kidney (p = 0.948) and in left kidney (p = 0.939). CONCLUSIONS: The number of renal clefts has a great variation, weak correlation and no tendency to decrease during the 2nd gestational trimester. The number of clefts in right kidney of total sample and female fetuses has a significant development with age.