Question
My son was born two days ago, and he has only urinated twice. The meconium has been quite a lot, totaling five times, all dark brown and sticky. How should I address this issue, is it normal? The baby is fed 90ml, what is the normal amount? And are there any requirements for the nipple?
Answer
Newborns already have the same number of renal units as adults at birth, but they are not yet fully mature in terms of histology. The glomerular cuboidal epithelial cells are more abundant, and the blood vessels are fewer, resulting in insufficient filtration area, which is only 1/4 to 1/2 of that of adults when calculated by body surface area. The renal tubules are short and underdeveloped, with limited reabsorption and secretion functions, generally only able to maintain normal metabolism. Due to poor urine concentration function, newborns need twice to three times as much water as adults to excrete the same amount of solutes. Normal full-term newborns start urinating within 24 hours after birth, with only 4 to 5 times of urination in the first few days due to less fluid intake. After one week, as fluid intake increases and the bladder capacity is small, daily urination can reach up to 20 times. Currently, both domestically and internationally, it is recommended to start feeding early to prevent hypoglycemia and hypothermia. Full-term newborns can be fed breast milk within 4 to 6 hours after birth. If breast milk secretion is insufficient, do not emphasize feeding on a schedule; allow the baby to suckle according to its needs to stimulate milk production. If breast milk is indeed insufficient, a small amount of formula can be given after each breastfeeding session. After feeding, the baby should be placed on its right side, and attention should be paid to observe for any regurgitation or vomiting to prevent aspiration. Premature infants generally start feeding sugar water within 4 to 12 hours after birth and can be fed milk if they do not vomit after two attempts. For those with weak suckling strength, breast milk can be expressed.