Growth scans - low femur length

[A1b2c3d4e5f6g7]

Hi, I'm not sure if this is the right section, but wondered if anyone had any experience of this. Had a growth scan at 28+4 and they flagged that baby's femur length was under 5th percentile. Humerus length was in proportion to the lower femur length (so also small, but not plotted on the graph).

This is in big contrast to the abdomen, which measured over 90%, and the head which was about 60% I think from memory.

Looked back through previous scans and his femur has always measured pretty small. I've another scan in three weeks, but getting very concerned about potential issues like skeletal dysplasia etc. I had the NIPT which was clear and the sonographer said the bones look fine, with no abnormalities identified at 20 week scan.

Did anyone experience this and what was the outcome? I'm not sure if I'm panicking needlessly, and it's kind of ruining how I'm feeling about my pregnancy at the moment. Just to mention also, at my dating scan I was moved forward by more than a week from my ovulation dates (I charted) so maybe he is just younger than they think. I don't know if this affects

I don’t know much about leg length on scans, so I am essentially bumping for you, but also want to say that I had extensive scans with my dd and saw an expert in the field, as there were fears she had a genetic abnormality. Her head was small compared to her abdomen which was off the scale. The concerns were a condition that can cause internal organs to be enlarged.
The scans thankfully showed that her organs were all normal, but it seemed she would appear with a large tummy and torso and a small head. She was completely normal looking when she emerged, and actually quite the opposite shaped sort of person, teeny tiny waist (she is a teenager now). So try not to worry too much while waiting for more detailed scans. Hoping it is also a false alarm for you, I do remember how stressful it was at the time.

@SirVixofVixHall thanks so much for taking time to reply, I really appreciate it. So glad it turned out fine and well with your daughter x

Just bumping this one back up to see if anyone else has had any experience they could share

Rebumping for you. It could have just been an isolated issue with that scan- was it done by the same people who did the 20 week one? What were the 20 week centiles?

This happened to me this summer, a Dr did a scan and told us that babies legs were on the 3rd percentile and his head was 95. Turned out the Dr was absolutely shite at doing scans and the rescan showed his legs at 30 percentile. He is 2 weeks old now and his legs are completely normal. There are so many variants that can cause inaccuracies in scans. The experience of the person, the quality of the machine and the position of the baby. After that disastrous scan I refused to let them scan me with the mobile scanner any more and insisted on an experienced sonographer and one of the proper machines.

This happened with DD, the consultant was obsessed with her having down syndrome. She's currently on my knee watching cbeebies with perfect but little legs.

Scans can be amazing for picking up problems but they also can be inaccurate and can honestly mean nothing more than your baby has little legs.

I had exactly this with DS now a completely normal 16yo (he does have my big head though).

Was rescanned a few weeks later and whilst reading was lower end of normal it wasn't concerning. Measured give at birth, they just put it down to the positions he was in during scans meaning accurate measurements were difficult

My little twins femur length was so below the centiles she never charted - I had regular scans and the doctors said that as I had had a low risk NIPT and she was growing at her own pace then they weren't concerned. She was born half the size of her twin brother and her legs were little but they are more in proportion now

Thanks so much, I'm glad it all came out well for you guys. And it's reassuring to hear other people's stories as well, so thanks so much for taking the time.

@ThirdElephant I had a private anomaly scan at 14 weeks and my usual 20 week scan. It looks like the legs were always a bit shorter but not flagged as under any centiles or an issue. Probably around 10-15% looking at the charts

My boy had a small femur length, I think around 10%. The rest was nearly 90th percentile. He was born absolutely fine and in proportions.

My experience was exactly the same as Loki01's.
DS is now a strapping lad who scored both goals in his footie side's 2-1 win today.
op
Hopefully he'll just have been in a weird position, or they measured it wrong. It does happen (quite a lot it seems)

My daughter femur length was 25th centile. No one raised an eyebrow not once. I have a healthy girl with short thighs

My DD was measuring large for head circumference and abdo and short on femur length on the growth scan.

She was 9lb, 92 percentile weight and 98 percentile head, but only 25 percentile ish (hard to get an accurate measurement on a new baby). She did have a huge head and stumpy limbs for a while, but is nearly 4 now and totally in proportion.

I don’t know anything about femur length specifically but my little girl’s head was just below the 5th percentile at 20 weeks while the rest of her was near average. I was extremely worried. Her head caught up with the rest of her during the pregnancy. When she was born it was on the small side of average, just like the rest of her. Scans aren’t totally accurate and babies don’t all grow in exactly the same way. Try not to spoil your pregnancy worrying.

My three have all had far shorter femur lengths than abdo/ head centiles- they're all perfectly healthy and fine.

First was iugr and born on 9th centile, she was absolutely tiny and her legs used to disappear in the early baby grows. 😂. Second was suspected iugr- her femur length dragged her expected birth centile down to 7th. She was born on 44th centile with little goat legs like her older sister. Despite weighing 1.5lbs more than her sister she still fit into the early baby clothes because of her dinky legs.

Wised up by baby three and suspected that I just grew babies with shorter legs. Third was also suspected iugr- again his femur measurement dragged his overall birth centile down to 8th. He was born on 44th centile too.

Scans can be up to 20% out. Position of baby, operator and the machine can all affect results. All of mine have been petite, which is odd because I'm not and neither is my husband. That said eldest is now all leggy and shooting up so I expect her younger siblings will be the same as they get older. X

Thank you so much, you've all put my mind at rest a bit. Looks like there can just be some real variation in normal baby development in the growth scans. Hopefully all will be okay in my case also.

@Teaandcakeordeath83 I think I was having the same worries a bit as we are both above average height also! However looking at my partner, I think his legs are a bit shorter and his torso longer, so maybe it's down to that a bit 😂 Just worrying when the Dr tells you they need to monitor it as it could point to some issue, although it could also be fine, and they won't know until the birth

My baby girl born in June had femur measurements that were around 1st percentile from 20 weeks, head and abdominal both around 40/50th. I ended up having twice weekly Doppler scans and being induced 3 weeks early and she was born a tiny 4lbs8, she does have small legs but she’s small all over. At 5 months old her weight is now 25th percentile and no other concerns have been flagged despite being told risks of various things while pregnant.

@SkyeJ90 thanks so much for the update, really appreciate, and so glad your little girl was delivered well and healthy!

@A1b2c3d4e5f6g7 no problem at all, I spent days and days looking online for other people’s experience when we were in your position so I like to share our experience :).
Enjoy the rest of your pregnancy!

Thanks @SkyeJ90 I know, I've done pretty much the same! It's just tough when you don't know either way and it's just waiting to see. This has really helped thank you

I had this with my second. Every growth scan the weight was average, femur below 5th percentile and head on 99th. Each time the sonographer used to ask if my partner was tall (we both are).

After every scan I saw a consultant who was never concerned and when I asked my midwife she again wasn't concerned. She said as long the baby keeps growing between each scan they are happy.

My baby arrived very average sized with normal leg and head size

Just coming back to update on this one, because I found that so useful when looking into other threads.

I had my 32 week scan last week and femur length had dropped to below 3rd percentile, so I was referred to FMU for another scan with a consultant. Consultant measured all of the long bones, and found that all were around or just below the 10th centile according to her measurements. The femur she measured as a bit bigger also, somewhere between the 6th centile and the 10th. She doesn't think it's a dysplasia issue (we are now one week behind on femur, as opposed to the three weeks from the scan last week) as she said she would expect us to be many weeks behind for there to be a major problem.

She thinks it could be a growth issue, so I have a scan again in another 2 weeks. Apparently isolated short femurs can point to asymmetrical growth issues, where the head and torso is prioritised for nutrition.

Just coming back to update after another scan at FMU. I'm 35 weeks now. Femurs are measuring about 8th-10th centile now and she didn't see any evidence of skeletal issues. This is still roughly almost two weeks behind I think, but she said for issues at this stage she would expect to see femur measurements off the chart at well below the 1st centile.

Have another scan in two weeks, will come back and update

I have a young adult who was on the 0.2 centile at birth, and for the first 9 months. I was told he may jump 2 centiles to the 2nd (or was it the 9th?), but more than that was extremely unlikely. In fact he is in the 75th.

My DS’s femurs were always on the low side, I can’t remember exactly but around 5-10th centile. Head and stomach always 90ish centile. I did worry at the time but all fine in the end. He does just have slightly short legs, which I only notice when buying trousers (currently just turned 4 in age 2/3 3/4 shop depending). Me and DH both tall but we’ve since discovered dh always small for his age until a teen, so imagine ds will be the same. Hopefully some reassurance there!