28 week scan showing short femur length?

[Becky230694]

Hoping to speak to anyone else that's been in the same boat as me and can offer any advice.

28 weeks pregnant with my 3rd have been having scans every 4 weeks since 16 weeks and my DH has an antibody that could cause foetal anemia so am under foetal medicine so far no issues no anemia and no cause for concern never been an issue on any of my scans before now. I had a new consultant do my scan today and tell me that my baby's femur length is 2mm shorter than it should be. I don't have any other soft markers on my scans everything is fine he even put down on my notes there was no cause for concern with abnormalities because he hadn't detected any and neither did my other scans. Blood tests at 12 weeks were 1/10,000 for downs and 1/100,000 for any other chromosomal issues. Me and my partner are both small I'm only 5ft 4 and he's only 5ft 7ish not tall at all. Consultant has obviously had to mention an amniocentesis but is it really necessary? My younger girl even though she has a different dad is tiny and was born very small but no problems also was never given growth scans for her and all of this babies measurements have been on the smaller side the whole way through. It's not like his femur hasn't grown its grown 8mm in the past 4 weeks. Any advice? It's really scared me.

I'm 35 weeks and my baby has short femurs since 20 weeks. His femur has been 3mm shorter. It's still just under 5th percentile now, and he is on 10th percentile for weight. I'm being investigated now because past 2 scans they can't find his left kidney and suspect it is pelvic/ectopic kidney, scan for that is on Friday. It has not been reported in my 20 week scan or numerous growth scans! If his kidney never ascended it will be fine as his right one is perfect, he will just need an ultrasound scan at 1 week old.

I'm surprised your consultant 'obviously' mentioned amniocentesis, is that partially due to the fetal anemia issue too? Your 12 week bloods look low risk to me, but I'm not a doctor! For me, I was low risk for 12 week blood test and the femur was not hugely below normal so my consultant is not one bit concerned about chromosome issues. She is not even considering it. Femur length is only a soft marker. 2mm is really not that far behind in relation to skeletal dysplasia or chromosome abnormalities. I've looked into this a lot because I was so concerned. At 2mm below at 28 weeks you're about -1 standard deviation (sometimes called z score), and looking at some studies I read, serious issues some from being -4 or more away from normal. You can read up by googling femur length z score if you like. But I guess trust your doctor if they recommend amniocentesis, there might be more to that recommendation than I understand.

I'd say definitely monitor it, and I have definitely been where you are in terms of worrying, but to me this doesn't sound extremely below normal to indicate an underlying issue. Hope this helps xx

What centile is FL on?

FL Is one of the most inaccurate fetal measurements. At one scan my son was borderline ‘red zone’ meaning he was 10th centile for FL, next he was about 50th. He was born 51.5cm long which will around the 75th centile.

Some trusts don’t even use FL to calculate EFW

No other reason was given for amniocentesis I think tbh it was a 'to save our own back' thing as there has been no other issues. Considering it was the first time I've been scanned by this consultant I've made a complaint because of the way I was spoken to and the situation was handled terribly. His FL is 2mm under 5th centile but he has always be on the 10th centile for weight since 20 weeks and I had a consultant consistently the same do my scans from 16 weeks to 24 weeks unfortunately she's left but she was very good and knew me and my partner were smaller and he was measuring small but healthy! I think I've just been scared by the way this rude doctor has spoken to me. I've spoke to my midwife today and she said she definitely wouldn't of been bothered about a 2mm difference considering he's growing normally .

Hi , my thread is below. My baby femur and humerus were on the 3rd centile at 22 weeks , all other measurements normal. Turns out to be a placental issue, downs and dewarfism were mentioned and I was worried sick.

www.mumsnet.com/talk/antenatal_tests_choices/4452526-Short-femur-and-humerus?page=1

Hi , thanks for that , thankfully it was an issue on the consultants part after 2 horrible weeks waiting and worrying for our growth scan everything was fine and has continued to be fine I changed consultants and I'm now just over 36 weeks and his femur are measuring just below 50th centile x