Bilateral renal agenesis

　　1. Etiology

　　The normal development of the kidney requires the normal ureteral bud to penetrate the metanephric primordium at the 5th to 7th week of human embryonic development. Factors that cause morphological or sequential changes, such as the lack of metanephric ridge or the failure to form a ureteral bud, will hinder the formation of the kidney. Although the absence of metanephric tissue cannot form a kidney, it is not clear whether renal agenesis is primary due to the abnormal development of the metanephric ridge or the ureteral bud. In 1965, Potter's research on fetuses and infants proposed that it is due to the lack of normal development of the ureteral bud. She observed that as long as any part of the ureter is present, kidney tissue can be distinguished. In contrast, in 1960, Ashley and Mostofi conducted a large number of post-mortem autopsies, revealing that many cases of renal agenesis have partial or complete ureters and their non-duct structures. They also observed that in cases of renal hypoplasia, the ureter did not form, although these findings are somewhat contradictory, they together support a theory that the ureteral bud directly stimulates the differentiation of renal parenchyma, and also point out that the cessation of renal differentiation may be due to the intrinsic static of the metanephric ridge itself.

　　2. Pathogenesis

　　The kidneys of the child are usually completely absent, occasionally with a small piece of interstitium containing primary glomerular components, forming an undifferentiated and incomplete organ, and fine blood vessels can be seen from the aorta piercing into this interstitium, with rare primitive glomerular components. The ureters may be completely or partially absent, and the bladder is often absent or underdeveloped.

　　50% of patients can have malformations of the cardiovascular and gastrointestinal systems. In male patients, penile development is generally normal, but there are also reports of underdeveloped penis. In 43% of cases, there is incomplete descent of the testicles. In females, the ovaries are often atrophic or incomplete, and the vagina is often a blind end or completely absent. Abnormalities or agenesis of the adrenal glands are rare. Under ultrasound, the adrenal glands are larger or in a recumbent position, and abnormalities of other organs are less common.

　　Due to the fact that the fetus does not produce urine, it often occurs with oligohydramnios in pregnant women, incomplete lung development in the fetus, and body weight ranging from 1000 to 2500g. It is accompanied by Potter facies, showing an immature aging appearance, with prominent skin creases above the eyes, curving around the inner canthus, forming a half-circular shape that hangs down and extends to the cheek. The nose is flat and sometimes without nostrils, with a small chin, a noticeable depression between the lower lip and chin, low-lying auricles close to the side of the head, broad and drooping lobes pointing forward, abnormally dry and loose skin, relatively large hands with claw-like shapes, underdeveloped lungs, common funnel chest, lower limbs often in an arched or club-shaped position, excessive flexion of the hip and knee joints, and sometimes the distal ends of the lower limbs fuse into a cleft deformity.

　　The etiology of this disease is not clear, it is related to autosomal recessive inheritance, usually related to marriage between close relatives, and this disease cannot be prevented directly. Patients with a suspected family history of chromosomal abnormalities should undergo genetic screening to avoid offspring suffering from this disease due to chromosomal inheritance after marriage. At the same time, attention should be paid to strengthening pregnancy nutrition, reasonable diet, and avoiding adverse stimuli that affect embryo development such as emotional excitement.

　　Performing a renal ultrasound after discovering anuria may lead to an accurate diagnosis, if abdominal ultrasound cannot confirm the diagnosis, renal CT can be chosen, radioactive isotope examination can also confirm BRA, if these examination methods cannot confirm or cannot be performed, angiography examination can be chosen.

　　1. What foods are good for bilateral renal agenesis

　　Eat light and easy-to-digest foods, fresh vegetables and a moderate amount of fruit, and drink enough water. Pay attention to a balanced diet and nutrition.

　　2. What foods should be avoided for bilateral renal agenesis

　　Avoid overeating and eating unclean food. Avoid seafood, beef, mutton, spicy and stimulating foods, alcohol, and all kinds of stimulating substances such as: five-spice powder, coffee, coriander, etc. Avoid all tonics, tonics, and easy-to-get-fire foods such as: chili, intelligence, chocolate, etc.

　　(The above information is for reference only, please consult a doctor for details.)

　　Prognosis

　　About 40% of fetuses are stillborn at birth, most neonates are born with respiratory failure due to poor lung development, and most die within 24 to 48 hours. The length of survival of other patients mainly depends on the extent of kidney function damage. It is reported that the longest survival time of BRA is 39 days.