20 week ultrasound small measurment

[hopefulmum27]

I've just been for my anomaly scan at 21 + 4 and all is measuring within range. Only one measurement is on the smaller side it's the CM (cisterna magna) which is 3.8mm and is showing as 9th percentile. Just wondering if anyone had anything similar? From what I'm reading online there isn't much info on this

I had similar. We didn’t get a percentile but mine was so low it was below the average range. The technician wasn’t worried and neither was my midwife when I asked about it - from what I understand (also struggled to find much on it) the concern is if it’s raised it can indicate something concerning (possibly spina bifida) but if it’s too low then that’s okay. I don’t think all trusts even check it and when I spoke to my parents (GP dad midwife mum) they weren’t even sure what it was without looking it up! I’m 32 weeks now and baby is enjoying punching its way out of me!

@FirstTimeMum1608 oh thank you that's reassuring! Do you recall what yours measured? Yes from what I'm reading I think it's more of a concern if it's a large number but I can't help but wonder why it's so much below the average too :(