Head measuring small scan

[lilspark]

Hiya mums, I just had a standard scan (not detailed anatomy one yet). I'm 20+4 but the scan was showing head circumference as 20+1 (so 3 days behind) whereas femur/abdomen etc were all 20+4 or 20+6. The doctor did not say this was concerning but I'm a little worried as to why only the head is on the smaller side? A scan I had 3 weeks ago showed baby measuring a week ahead in all regards so why has it slowed down? Is it normal?

Hi, a few days here or there for any measurements won’t flag as concerning, as it’s quite hard to be that precise. I was told my baby’s femur was on the 7th centile (so 93% of other babies her age would have a bigger measurement here) but I’m 27 weeks and her head is measuring as if she’s 30w! It’s all just natural fluctuations and they’d follow up with it if it triggered any concerns.

@Luluem aw thanks it's reassuring to know I guess it's just the range that matters then! I guess a lot can change any time as 3 weeks ago baby was measuring a week ahead and now it's slowed down. As long as they're ok in the end that's all that matters :)