Urate Crystals

New parents are sometimes concerned to find dark pinkish-orange spots in their intact (not circumcised) baby’s diaper during the first few days of life, and worry it might be blood in the baby’s urine. In almost all of these cases, however, the substance that looks remarkably like blood in a diaper is actually not blood at all, but rather what is known as urate crystals or uric acid crystals.*

The appearance of these crystals — sometimes referred to as “brick dust” or “brick powder” (since it turns to powder if left to dry) or “pink diaper syndrome” — results from a high concentration of uric acid. This transient occurrence is common for babies in the first few days of life, particularly if they are breastfed/chestfed. A quick Google Image search for “urate crystals in diaper” can provide a visual to compare with your infant’s diaper. (Note: Urate crystals appearing beyond the first few days after birth or appearing repeatedly in the diapers of a newborn can warrant an evaluation to ensure the baby is transferring sufficient milk effectively and eating often enough. Always talk with your child’s healthcare provider about any concerns you have.)

A nursing parent produces very small, concentrated amounts of colostrum until typically beginning the transition to larger volumes of mature milk around the second or third day (sometimes this can take a little longer). A baby consumes an average of one to two teaspoons of colostrum per nursing session in the first 24 hours of life. During the next 24 hours or so, an infant still takes less than one ounce per feeding, one of the many reasons newborns nurse so frequently. Colostrum is important during this time — it contains exactly the correct mix of nutrients and immune factors, in the right amounts, for a brand-new baby. It’s essential to note that colostrum is supposed to be produced and consumed in these small amounts as the parent’s body prepares to shift to mature milk production. The low total fluid volume and high protein content of colostrum can contribute to the formation of urate crystals.

If any crystals are seen, they should clear quickly as the baby begins to consume larger volumes of transitional human milk around day three and urine output increases. It is important for parents of newborns with intact penises to be knowledgeable about urate crystals, so a baby can remain safe if professional medical/breastfeeding evaluation is sought for urate crystals, especially those visible beyond the first few days of life or at several diaper changes. Many healthcare providers in the United States are still unfamiliar with foreskin functions and care. If a particular provider is also unfamiliar with urate crystals and their causes, a baby can wind up receiving incorrect treatment, including forced retraction, catheterization, or antibiotics. Parents can be aware that urate crystals are not caused by infection, and thus prevent their child from experiencing unnecessary and harmful medical interventions.

Urate crystals also can be seen in older babies and children. This often indicates some level of dehydration, which can result from occurrences such as fever, a reduced number of feedings or volume of human milk or formula, or a shift to warmer weather. The issue typically resolves when fluids are increased. Again, always bring your concerns to your child’s healthcare provider.

*If an infant has been circumcised, there is a risk of bleeding/hemorrhaging from the wound site, and diapers must be closely monitored.

True bloody discharge from the vulva may occur in the first few days of life, resulting from in utero exposure to the birthing parent’s hormones, and is normal.

References:

Colostrum: General. https://www.llli.org/breastfeeding-info/colostrum-general/

Lauwers, J., & Swisher, A. (2016). Counseling the Nursing Mother: A Lactation Consultant’s Guide (6th ed.). Burlington, MA: Jones and Bartlett Learning.

Rennie, J.M. (2012). Hormonal effects in newborns. http://pennstatehershey.adam.com/content.aspx?productId=117&pid=1&gid=001911

Last updated: January 2, 2021