Huge drop in percentile number

[Shamoo]

Hi all - hoping for some advice.

My wife is 26 weeks pregnant. We have had 12 and 20 week scans showing baby at 95% with our initial hospital. We have also for anxiety reasons had scans at a private hospital who have put her on the 97%. The last one of those was 10 days ago. Movement has been generally ok and kicking is strong.

Today we had a scan at a different NHS hospital (as we are in a different location now) and they have said she is on the 10%. They have just said this is because of different algorithms being used but are unwilling to look at the other hospital data so won’t go any further than that or do anything. But obviously this is very worrying and also my wife has very high anxiety anyway is very very upset. I am not allowed in to speak to them because of covid, which I understand, but it makes moving forward difficult.

Has anybody ever experienced this? Any suggestions on what we should do?

Anyone?

If private scans are just going to heighten your wife’s anxiety more I wouldn’t go for any further private scans. Private scan clinics could be working out the estimated weight using a different formula and not personalised to your wife. The grow charts used to plot a scan are personalised using your wife’s demographics. Why did your wife have the growth scan today? Will she be having a follow up?

Hospitals have moved away from looking at the overall percentile as apparently it's based on data from women in the 70s. What the sonographers will be monitoring is how your baby's individual measurements like the head circumference (HC) and abdominal circumference (AC) have changed over time. So long as these haven't had drastic reductions then there's nothing to worry about.

I had a drastic drop in percentiles and was induced a few hours later.

I would say if there was something to worry about you would know about it. They are right that they all use different ways of measuring and with my growth scans I could fluctuate between 15 - 50 percentile. You need to see the same person ideally and the same hospital for it to be tracked properly otherwise it’s like comparing apples and pears.

Thank you all for sharing. I really appreciate it.

We were at the private hospital because they couldn’t book us in to the nhs for our first scan until 14 weeks and we really wanted to be seen earlier, so we went. It was a godsend in the end as when we finally got seen at 14 weeks it was too late to measure for Down syndrome, and we needed to rely on the private measurements when the bloods came back high risk.

Today’s scan was due to some reduced movement last week, although that has resolved itself they told us to still come in. Really wish we hadn’t gone now. Done a lot of research this evening and got comfortable that hopefully it’s all ok.

Thank you again everyone.

Also had this happen. A sonographer missed a leg or something like that when calculating their measurements...

I'm confused OP. Did your wife have reduced movements and go for a private scan rather than to the hospital?

Theyve told you they use different formulas so that's why things are working out differently. You need to trust to sonographer and midwives to alert you to any concerns regarding growth etc as they are the professionals trained in that area.

Ok, so breathe. Is it the estimate fetal weight that is 10th centile? They use something called the hadlock conversion based on abdominal circumference, head circumference and femur length. What scan did she have at the new hospital? Anything above the 10th is considered ‘a-ok’ so don’t worry. If you are concerned I’m sure you can ask for a growth scan at 28 weeks and arterial dopplers to check the flow through the placenta? As long as baby tracks along that centile there is likely no problem. Try not to worry.
My little girl was on the 5th, we were induced at 37 weeks as she consistently followed that centile

@MotherPiglet - no the reduced movements meant we went into the NHS hospital where they gave her two days of doplar reviews and then on the third day (yesterday) the scan where they put the baby at 10%, but said everything else looked ok.

The private scan was purely because our 12 week NHS scan wasn’t actually booked in until gone 14 weeks as they were so busy, and we were anxious and went private at just before 12 weeks. We’ve then had NHS at 14 weeks and 20 weeks. Then a check in 10 days ago at a private scan to just see her. All those scans show her at 95% (ish). Then this NHS one yesterday suddenly put her at 10%.

Thanks @Sleeplessemma - yes it’s the estimated weight. I wouldn’t be worried if we hadn’t had four other scans tracking at 95%. It just seems such a huge thing to change. They have offered us another scan in two weeks to check again.

They weren’t able to explain it really, so we are trying to be calm about it and just see what happens.

Thanks all for your support.

@Springb0ks - we can’t rule that out to be fair!

Have they actually said these percentages to you? Apologies for my ignorance but I've never heard these percentages in scans, only when they do the bump measurements.

If they've offered to scan again in 2 weeks then it sounds like just a case of wait and see what they say then but if they arent concerned I would trust in the professionals. Is your wife feeling the baby move etc normally?

So the scan in 2 weeks is a follow up growth scan to see if baby is still tracking the same centile and to see if blood flow is ok. They can’t do them more regularly than that as it won’t show any real growth for baby. This is good they are monitoring babys growth now closely. If baby is 10th or higher is nbd! But they might offer you another follow up in 3 or so weeks just to be sure.

If baby has dipped below a bit they’ll probably refer you to fetal med, if that happens please don’t panic! They are frankly just more qualified than a sonographer and they will do their best to get your baby to term!

I’ve been through this so shout if you have any questions! X