Urate Crystals in Baby Nappy: Brick Dust Explained | Parenting Hub
Pink, orange or 'brick dust' staining in a newborn's nappy is usually urate crystals — normal in the first few days, a red flag after.
Pink, orange or rust-coloured 'brick dust' in your newborn's nappy is usually urate crystals — normal in the first few days while milk is coming in. After day 4–5, it can be a sign of dehydration.
What it is
Concentrated urine in the first days of life can leave pink, orange or rust-coloured powdery stains. It's urate (uric acid) crystals — not blood.
When it's normal
Days 1–3 while milk is still 'coming in'. It usually clears by day 4–5 as milk volume increases and wet nappies become more frequent and pale.
When it's a red flag
After day 4–5, or if appearing alongside fewer than expected wet nappies, it suggests baby isn't getting enough milk. See your midwife or GP the same day.
When to seek help
- Brick dust persisting beyond day 4–5
- Fewer than expected wet nappies for age
- Sleepy, hard-to-wake baby
- Sunken fontanelle, no tears, dry mouth — ED now
Common questions
Is it blood?
Usually not. Blood tends to be red or brown and concentrated as a streak. Urate crystals are powdery, often spread over the nappy. If unsure — show your midwife or take a photo.