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Baby's head and abdomen measuring big, femur measuring small

8 replies

Apbakes · 12/02/2024 09:33

I had a private scan yesterday, and have got myself very worried about the discrepancy between babies head and abdomen measurement vs femur length.

I was 31w 6d at the appointment. His head is in the 90.66 percentile range, abdomen is in the 78.81 percentile range whilst his femur length is only 7.35 percentile.

Both me and my partner are tall, he is 6ft 2 and I'm 5ft 7, so I don't think it's that we are shorter individuals. But we do both have longer bodies to shorter leg ratios.

The ultrasound did mention he had little legs, but I brushed it off at the time... but then the inevitable anxiety hit in the middle of the night. Would she have mentioned anything as it was just a reassurance type scan.

Am I over thinking this? Has anyone else had the same and it ended up being OK?

OP posts:
BrightGreenGoose · 12/02/2024 09:53

I've not experienced this, but my advice to anyone worried about anything in pregnancy would be talk to your midwife.
I'm sure that was there any concern it would have been noted at your anomaly scan (20 weeks) and she will be able to explain it to you.

Lijay · 12/02/2024 10:19

My DS had short femur length only picked up at the 32 week scan. I can't remember the exact percentile it was on but it was very low. The sonographer brushed it off at the time. Like you I went into Google panic mode after but didn't need to. He did have short legs but not out of proportion when he was born. He's 15 months now and definitely his torso is longer than his legs but id say it's starting to even out. No health issues, completely healthy.

cantitbesimpler · 12/02/2024 10:26

I remember worrying about the opposite, OP - my baby's oddly long femurs and smaller head. Then I realised I am also a bit like that. She turned out fine!

You say you both have longer body to legs ratio, I would say it's likely your baby has too. Remember they are ranges, and your baby is in the normal range. It's very rare to be middle of the range for everything.

anotherdayanotherpathlesstravelled · 12/02/2024 10:33

Babies grow head down - it's normally for their heads and abdomen to be on a higher centile

CheeryBiscuit · 12/02/2024 11:56

Very normal to have head, abdomen and femur on different ends of the spectrum centile-wise. These are all very normal sizes and nothing to worry about :)

SH998 · 12/02/2024 12:28

I've experienced the same pretty much throughout my whole pregnancy with his femur going up and down, first time they measured he was 13 percentile, second 21 percentile, third time 48 percentile then last scan 8 percentile. I freaked out every time.
I called the midwife to discuss and she advised NOT to look online or google, the NHS have their own way of recording results and as he was showing overall 50 percentile they seen no issue with it.
She said if there was any red flags we would be informed by the NHS immediately.

Apbakes · 12/02/2024 13:11

Thank you all! This has reqlly helped put my mind at ease!

OP posts:
Grace185 · 12/02/2024 23:00

My son was exactly the same. I had 2 weekly scans throughout due to an unrelated issue and he was always short, fat and with a big head! They thought he'd come out huge but he was average. He's two now and is a small little thing but nothing to worry about. He's just short.

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