Percentile measurements

[Bells3032]

Do measuring percentiles mean anything? At my 12 week scan baby was 37th percentile. Today at 18 weeks she's measuring 20th percentile. Bit worried that's on the low side.

Measured by different people at completely different hospitals etc

Looking for a bit of reassurance.

Yes percentiles do matter, more than “weight” as babies weight is a complete guess based on baby’s measurements. The percentiles however are true reflection of baby measurements. Yours are completely fine. I think you need to worry when baby is in the lowest 5%. Babies grow at different rates and have growth spurts. I mean I wouldn’t expect your baby to be 90% at his next scan but certainly he could be 40%. My baby this time started at 80% then he was 50% and last scan 60 something. Yours is perfectly fine too. Maybe if he/she was 80 and then 20 - that would be some concern if you get me…don’t worry all is fine x

OK thanks. Was worried it had gone down but that's reassuring it can go up again. Thank you

I know how worrying it is, I've had lots of centile-related thoughts! Your midwife will start measuring your bump soon and as long as you're following a general line (so you'd be looking at sitting around the 25th centile line at a guess but I'm not a medical professional) you'll be left to it. If midwife has any concerns about bump size she'll send you off to get a growth scan and get accurate measurements.

With my first she measured about 40th xentile all the way though but then at my last appointment she had dropped sharply so was sent off for growth scan. She came out at 9th centile but this didn't come with any extra issues and she's about 30th now.
With this baby because my first ended up being small I've had extra monitoring and sure enough looks like she will be similar. I've another scan next week where if she's on or slightly above the 10th like she was last scan then I'll probably be allowed to go to 39 weeks but if she dips below it will be more like 37 weeks but that will be a conversation with the consultant.

So long story short you will be kept an eye on but those centiles are nothing to worry about 🙂

My baby is on the 2nd centile and dropping, so honestly the 20th centile is fine. It can yo-yo up and down too so hopefully now they’ve seen a drop they will keep an eye on you

20th centile is absolutely nothing to worry about, especially if under 50th before, there is a natural fluctuations and baby hasn’t dropped more than one standard deviation.
Anything from the 3rd centile up is considered ‘normal’. They watch you a bit more if baby is under 10th but this can still be normal. Did you have arterial dopplers done? This is the best indication of how the placenta is functioning.

She checked the blood flow in the placenta and said it's normal. everything else seemed normal.