Can anybody tell me if the guidelines for growth have changed in the last 3 years in terms of normal variation across centiles?
At baby clinic today, my 15 week old DS2 plotted in between the 2nd and 9th centiles (5.4kg). When he was 4 weeks old he was on the 25th (4kg), and at 9 weeks old he was just above the 9th (4.8kg). Overall then, he's dropped 1.5 centile widths in 11 weeks. The nursery nurse (we get both HVs and NNs in our baby clinic) didn't notice this pattern but gave me an earnest talk about how the half-centile change between 9-15 weeks was a drop that needed attention and to come back again in 2 weeks to see if DS has gone back up to the 9th.
As I was dressing DS, I overheard a HV say to another mother that they expect babies to stay around their birth centile and any baby that goes up or down by more than one centile "needs to be seen to". (No privacy in the clinic room, unfortunately). I realised then that if they'd noticed DS2 had dropped 1.5 centiles, they'd probably have gone into panic mode. 
When 3yo DS1 was a baby, they weren't concerned unless two centile widths were crossed, and they discouraged weighing more than once a month unless this or other concerns had been raised. There was certainly none of this idea that babies who plot half a centile space lower than last time need fortnightly follow-ups until they return to a higher centile.
Has something changed or have the local clinic policies gone rogue? DS2 is a chirpy wee chap and I had no worries about him or his feeding (he's ebf), so I'm disinclined to go back to the baby clinic if they're giving out incorrect advice.