Jack was born late on a Thursday night via vaginal delivery. He had good APGAR scores. He voided in the delivery room and passed meconium shortly thereafter. I saw him first thing on Friday morning and his newborn examination was normal. Mom started breast-feeding and this seemed to be coming along just fine.
Saturday morning I found that he was not jaundiced, had passed the hearing test and had his circumcision. The breast-feeding was being well established as he was latching on well and mom felt comfortable about this. They were discharged early Saturday afternoon.
A distressed call came from mom Sunday afternoon. She said when changing his diaper there was “a lot of blood in it”. He did not have a fever, was eating well and passing meconium almost every feeding. He was content and did not seem uncomfortable or fussy at all. Asking her to describe the diaper she said it was heavy, suggesting that there was a fair amount of urine in it. But it was reddish in color, “full of blooThis sounded like urate crystals in the urine which is a very common finding in newborns, and is of no concern. I could sense that this was not allaying her fears. I had her do a Goggle search on the topic to see if this didn’t explain exactly what she was observing. Ten minutes later I called her back. In amazement she said, “Oh my gosh, the pictures are just like what I am seeing.”
We spoke a bit more about urate crystals, what they are and why they occur. I told her to bring the diaper in on Monday and I would test it for blood. In the meantime be sure that Jack is eating well and having a good urine output.
The next day the baby was just fine. The original diaper had dried. The area that mom thought had blood formed an orangish or brick colored stain that became powdery. It was tested for blood and was negative. Upon examining him he had a wet diaper that did look very much like blood. Again this diaper was tested and it too was negative. Mom was greatly relieved.
Urate crystals are common in the newborn urine. They are comprised of calcium and uric acid, and can form a reddish-orange stain in the diaper. The excretion of uric acid is very high in the newborn. This decreases as they approach childhood, reaching adult levels at about that age. Factors that can favor the formation of urate crystals are dehydration and an acidic urine.
A breast-feeding mom produces colostrum initially until the milk supply comes in around the third day. While the colostrum is sufficient nutritionally, the baby may be a bit behind on fluid intake in the first few days of life. This can contribute to the formation of urate crystals. Colostrum, as well as breast milk, has a high protein content that favors an acidic urine. This, too, can contribute to urate crystal formation. This explains why urate crystals and “red urine” are so common in the first few days of life --and are of no concern. Once mom’s milk supply is well established and the baby is having good urine output (at least 5-6 wet diapers a day) the urate crystals should disappear.
Whenever this occurs it is a good idea to test the urine for blood. If anything it will allay any fears mom may have because it sure does look like blood in the diaper. If the crystals persist beyond the first few days of life it is imperative to insure that the baby is well hydrated and having at least six wet diapers a day.