20 week scan showed short femur length - on 5th centile - but im 6 ft tall and very lanky!!!

[Beastycat]

Hi all,

I hope someone may be able to reassure me. I had my 20 week scan yesterday. As she did the measurements, she said everything was fine. As we were waiting outside for all the paperwork, she came out and said that according to the computer,the baby was small for 20weeks. Only in the 5th centile, so i would have to come back for another scan in 2 weeks.

I was very worried, but then had a call from them this morning to say that it looked as if 'the computer had made a mistake' and most of the measurements were okay - a little lower than average but not much - and only the femur length was on the 5th centile.

After a google search, this has now worried me even more, as this means that the baby is out of proportion and could be a sign of dwarfism/ down's? A short femur length is all the more concerning as am 6 foot tall with a 35 inch inside leg measurement, and my husband is also 5"10!

I would very much appreciate any advice. I think i may go for a private scan ahead of my next scan in two weeks, as i am really worried now and would prefer to know.

Many thanks to anyone who responds.

Please don't panic just yet!!! See what happens at the re scan. The growth isn't always strait forward sometimes they stop momentarily then catch up. It's one measurement on one scan. The baby could have been lying funny or the computer
Mis measured. It happens all the time. :)

Step away from google!

It is likely that it was a mistake, so try not to worry too much. Scanning is not exact. "The computer made is mistake" sounds like "the sonographer made a mistake but we don't want to admit that".

If it would reassure you then going for a private scan would be good, if you can afford it.

I agree, one measurement on one scan is not conclusive of anything. It's very easy for the baby to be in a difficult position to measure accurately, and 20 weeks is very early still so a lot can change.

Maybe the 1st growth scan measured the baby wrongly and you could in fact be 19 weeks? Don't worry much. My first baby was always on track and his legs were very short compared to the rest of his body which was massive in comparisson! But nobody told me that his legs were too short so I don't know. When he reached 2y his legs grew much taller and caught up with the rest of his body :) My 2nd baby was born a bit shorter but he is growing taller than the 1st! He had fantastic growth spurts during the first month after he was born!

If you are worried, call them back and ask about it. They will be able to either talk it through with you on the phone or refer you on to your MW or someone else who will be able to answer your questions. Don't sit and stew!

Bear in mind that 5th centile is still within the realms of perfectly normal :)

'The computer made a mistake' sounds more like 'the sonographer made a mistake' which means we need to re-scan you. We still need a reason to do this but as we are not going to admit we made a mistake we are going to pretend one of the measurements was a bit dodgy so we can call you back
Is a rough translation

'The computer made a mistake' sounds more like 'the sonographer made a mistake' which means we need to re-scan you. We still need a reason to do this but as we are not going to admit we made a mistake we are going to pretend one of the measurements was a bit dodgy so we can call you back
Is a rough translation

By that, I mean concerns usually arise when baby isn't on the centile charts.

At DS's 12w scan (which was what I thought was 15+4 and turned out to be 17w) we got 3 different gestations for each measurement - his legs were 15+4w, his abdomen 16w and his head 17w. A measurement that isn't in proportion with the others isn't necessarily a sign that something is amiss.

They caught baby at one moment , it's one snapshot of 20 weeks so far. Your baby is going to grow immensely between now and his or her due date. Not all babies grow according to charts. Have the re s an and go from there :) they seem to panic in hospitals and get you worked up over what often turns out to be nothing!

Please try not to worry. It is one measurement in isolation and babies can lie in odd positions and sonographers can make mistakes. And remember the measurement is still normal. If there was anything significant to worry about there would be far more markers than one potentially rogue bone measurement at 20 weeks. I am really, really short, dh is slightly shorter than average, our dc are both really tall and have big feet (I have tiny feet, dh again smaller than average). They don't take after us at all oddly.

So even if the measurements are right, 5th centile is nothing to worry about.

DS2 is on the 5th centile. It just means that he is usually one of the littlest in his class, but well within 'normal' ifkwim.

Thanks to all of you so much for the reassurance, you have made me feel a lot better. I certainly have no problem with a small baby (they told us yesterday its a girl, although clearly that could be a mistake too..!) was just worried about what else that could potentially mean. Many thanks again to you all for taking the time to reassure me.

I've been told at 36 week growth scan femur length is really long and we are not very tall ppl? Also the baby has plenty of time to grow ! It may have slowed down a bit then will play catch up !

My DS had short long bone measurements, lower than 5th centile. We were told it could be a soft marker for dwarfism etc, or a sign of iugr (not relevant for you as all the other measures are ok) or just be a short baby. We were scanned lots, as he also had another soft marker. DS was indeed short despite DH being 6 ft 5, and he still is about 2nd centile.

He is otherwise totally fine though. The likelihood is an error in scanning, or that baby is short and that's just the way she's supposed to be. Try not to worry.

Hi there and poor you to have this worry. DD1 had short femur length all the way through her scans. I had loads of scans due to other things. I can remember googling Dwarfism and links to Downs. She is now a tall 3 year old with lovely long legs. Please try not to worry too much and I hope the re-scan provides some reassurance.

Hi. I agree with everybody else that it is most likely nothing to worry about, but I just wanted to add, I have a son with dwarfism and he is wonderful, so if you ever needed to talk in the future, don't hesitate to pm me.

Purely anecdotal but I work with a girl who is 6'2". Her parents were both over 6 foot, as is her brother. Her sister is 5 foot exactly! It can happen...!

Like cheekychops I was told at 34 week scan that DS1's femur length was 40 weeks+. I was Now he is 12 - there is certainly nothing unusually long about his femurs - he is in age 12 trousers and has never needed any longer than his age. In fact when he was a toddler he needed younger aged trousers as the right age were too long.

I think the differences between 1st percentile and 99th and probably tiny.

I was told at a late scan about 38 weeks that my DS had very short femurs - no centiles were given and it was done by a young dr who I think was doing the scan for practise. I'm 5'11 and DH is 6'2 so I too was worried about dwarfism. Anyway, DS arrived and was a long skinny baby with perfectly normal legs and is now a long skinny 9yo, who is longer in the body rather than legs but still perfectly normal.

I'd be thinking screw up from the sonographer.

We also had this with ds3, femur length less than 5th centile & everything else around 50%. We had a lot of extra growth scans and it stayed like that, he is now 10 months old & perfectly in proportion :) As others have said they grow at different rates & the range between the 5th and 50th centile is only millimetres so easily skewed. Congratulations on your baby girl, I'm sure she will be perfect x

My baby girl had short legs on the scan, and she still is a little short in the leg now, but they are definitely catching up with the rest of her (21 months now), and absolutely no dwarfism.

Try not to worry :)

I spent most of DD's first year worrying as she is only on a very low centile for length - and I think it predicted she would end up about 5'2" or something. DP well over 6', I'm 5'10": I was utterly convinced she was therefore malnourished/dreadfully ill/ooh all kinds of random things.

She's not: she's just not very tall. Yet!