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Antenatal tests

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Flip

Original poster

Short femurs, big head!

14 replies

TheBerry · 29/04/2022 10:50

I'm 20+6 with my first baby and yesterday I had my anomaly scan.

The sonographer said everything looked fine, and I was very relieved.

However, when I was reviewing the actual data afterwards🤦🏻‍♀️ it seems that my baby's head (HC) and abdomen (AC) are about a week ahead in size, whereas his femurs (FL) are about a week behind.

His femurs are down in the 10th percentile. Also, they've definitely got my gestational age wrong at 20+3 - I was actually 20+5 yesterday, which would put his femurs in less than the 5th percentile.

His femur to head/abdominal ratio is less than the 1st percentile!!

It's making me feel really worried about some sort of trisomy or other problem.

His head has always seemed large in comparison to his legs, but at my 16w scan it was more like his legs were about the right size for his age and his head was big.

It just doesn't make sense because I'm tall, and my boyfriend is also pretty tall. Does anybody know if this can be normal and can just correct itself as my baby grows, or whether it's more likely something is wrong?

OP posts:

BabyOnBoard90 · 30/04/2022 02:44

TheBerry · 29/04/2022 10:50

I'm 20+6 with my first baby and yesterday I had my anomaly scan.

The sonographer said everything looked fine, and I was very relieved.

His femurs are down in the 10th percentile. Also, they've definitely got my gestational age wrong at 20+3 - I was actually 20+5 yesterday, which would put his femurs in less than the 5th percentile.

His femur to head/abdominal ratio is less than the 1st percentile!!

It's making me feel really worried about some sort of trisomy or other problem.

His head has always seemed large in comparison to his legs, but at my 16w scan it was more like his legs were about the right size for his age and his head was big.

Babies come in different sizes and shapes like us children and adults.

If the sonographers haven't found something to be cause for alarm, then I wouldn't be worried.

NotABeliever · 30/04/2022 03:28

The measurements they take are not accurate. One pixel can make the difference. It's probably.down to.how accurate the sonographer was in taking the measurements.
If they're not concerned, I would not worry at all.
Congrats by the way!

mubarak86 · 30/04/2022 03:37

If they are not concerned (and they would have told you if they were) then there is really no need for you to worry.

Reallyreallyborednow · 30/04/2022 04:47

Also, they've definitely got my gestational age wrong at 20+3 - I was actually 20+5 yesterday

unless you had IVF and know the exact date it’s incredibly hard to be this accurate.

growth can vary +/- 2 weeks. A day here or there makes no difference.

as pp have said measurements aren’t that accurate either. And unless you have a background in foetal medicine then it’s likely your interpretation is incorrect too.

is there a reason you went and looked up all this? Are you anxious?

romdowa · 30/04/2022 05:24

I was told at one stage that my babies feumers were almost off the charts they were so small and that his head was weeks ahead. Turned out the person doing the scan measured wrong. I now have a perfect 6 month old , with normal sized legs and head. These scans can be so inaccurate and babies also grow at different times, just like us. Another few weeks and they will probably have evened out

Bridie20 · 30/04/2022 05:31

By the last scan we had (36wks) my baby’s femur was 3 weeks behind and his head was off the chart so more than 4 weeks ahead. He was born perfectly in proportion. He has a slightly big head but that’s just him and it isn’t abnormal in any way. Honestly I think it’s fine if they weren’t worried xx

SkyeJ90 · 30/04/2022 23:23

My baby had short femurs at 20 weeks also and they stayed that way through my whole pregnancy, I have read other experiences of them having growth spurts or it just being an incorrect measurement also though so that could also be the case. My daughter is perfectly fine she is just petite :)

Jericha · 30/04/2022 23:32

At my 20 week scan my son's femurs were something like 8th centile, abdomen 60 something and head 90 something. Sonographer wasn't concerned.

He was fine at birth, just a big head and slightly little legs that looked lost in his babygros. We did discuss his head size with the HV when he was a baby at weigh in and an appointment with the GP was suggested by the HV to ease our concerns. Doctor wasn't worried.

By 1 year his legs had caught up. He's now 5 with a big head still (like his parents and cousin!) but average height/leg length.

thinkfast · 01/05/2022 23:02

Scans are really that accurate for size. If the sonographer said it looks fine, it looks fine.

thinkfast · 01/05/2022 23:02

*aren't really that accurate

BAIL08 · 13/06/2022 17:08

Hi all

I’ve just had my growth scan at 32 weeks and 3 days and baby boy is measuring at the 97th percentile - I think it may be the abdominal circumference.

The hospital wants me to test for gestational diabetes.

I’m so worried about this. All of my urine tests have not had any glucose in it. I’m not overweight and eat relatively well (although maybe too much fruit).

Is there any chance this is just a big baby, or is the likelihood with the measurements that it’s GD?

I know no one can say for sure, but just wanted to hear any other stories.

Thanks very much.

MD1604 · 31/12/2022 00:23

@TheBerry Hi! Sorry I know your post was from a while ago but wondering if you can let me know how you and baby are? I have just had a growth scan and have literally the same measurements as you and I am really worried about the difference in head/leg size. Thanks!

Original poster

TheBerry · 31/12/2022 01:06

MD1604 · 31/12/2022 00:23

He seems fine! We had loads of scans and the measurements varied a lot, even towards the end. I think on his last measurement his head was actually smaller than average and his femurs were normal 🤷🏻‍♀️ so you do have to take the measurements with a pinch of salt, I think.

Now that he’s born, he seems in proportion. He’s quite long, but not very fat, and although I think the length is mainly in his torso it certainly isn’t noticeable if his legs are shorter than average (and I don’t think they are). His head seems smaller than average if anything but, again, not noticeable.

Just try to trust the doctors is what I’ve learned. They’re experienced and will flag up anything worrying 🙂

OP posts:

Babyisi · 12/06/2023 19:32

TheBerry · 29/04/2022 10:50

I'm 20+6 with my first baby and yesterday I had my anomaly scan.

The sonographer said everything looked fine, and I was very relieved.

His femurs are down in the 10th percentile. Also, they've definitely got my gestational age wrong at 20+3 - I was actually 20+5 yesterday, which would put his femurs in less than the 5th percentile.

His femur to head/abdominal ratio is less than the 1st percentile!!

It's making me feel really worried about some sort of trisomy or other problem.

His head has always seemed large in comparison to his legs, but at my 16w scan it was more like his legs were about the right size for his age and his head was big.

So happy everything went well - im
On the same boat and wishing i could enjoy the let weeks of pregnancy 🙏🏻

Flip