Baby Crossing Percentile Lines | Parenting Hub
Small wobbles between percentile lines are normal. Crossing two major lines up or down is worth a check.
Babies don't grow in a perfectly straight line. Most stay roughly along their own curve, with small dips and bumps.
What's normal
Most babies follow their own curve fairly closely after the first 6–8 weeks. Small movements between percentile bands are common around growth spurts, illness, teething and starting solids.
When to ask for a review
- Weight drops across two major percentile lines (e.g. from 50th to below 9th)
- Sudden jump up across two lines
- Length or head circumference also falling off
- Feeding has changed and baby seems unsettled
When to seek help
- Sustained drop across two major percentile lines
- Falling on weight, length and head together
- Lethargy, poor feeding, fewer wet nappies