Please help. Femur measuring 3 weeks behind at 34 weeks

[smokealarm]

Can anyone call me down?

Had a growth scan at 32 weeks (I'm scanned regularly due to a previous late loss), and our baby's femur length had dropped from 20th percentile (from 28 week scan) to 9th percentile. Re-scanned today at 34 weeks and the femur has dropped to below the 5th percentile or 3 weeks behind.

The humerus is measuring 2 weeks behind.
The baby is measuring on the 30-40th percentile for everything else including head circumference.

I've been referred to a fetal medicine consultant on Thursday for another scan but in the meantime I've been googling and it comes back with the possibility our baby may have Down's syndrome or dwarfism.

I had the Harmony test done privately in early pregnancy which came back negative to rule out Down's syndrome but nothing is 100% is it?

Can anyone shed some light?! I'm crying and panicking and DH away for work so no one to talk to.

I just feel so unlucky given our history of losing our son in a previous pregnancy. To get so far along again and for something to go wrong just has me in bits.

It is very difficult to get accurate scan measurements. I was referred for growth scans with DD as I measured small. One of the measurements (might have been head circumference but not sure) came out at 3rd percentile. Sonographer remeasured and it came out as 25th. Other measurements were all 50th. It is good they are taking it seriously and looking in to it, but it doesn't necessarily mean something is wrong. for you whilst you wait to find out more.

I had this with one of my twins, poor love just has short legs. Try not to worry x

Thanks for the replies. I'm hoping it is just a case of short legs! It's odd though as neither DH or I are short.

I don't think there's any scanner variability as the small measurements have been consistent

Her legs were under the 2nd percentile. Have they said why you’re being referred? We had to have additional scans as they were worried the placenta was giving up

I know it's hard but do try not to worry. It is very difficult to get accurate measurements at that stage in the pregnancy.

At least they are taking it seriously.

Very very unlikely to be Downs given you've had the harmony test done.

Much love x

Me and my husband are tall and so is our 15month old toddler but she does have short legs. Every time her body length gets too big for her onesies, we move her up a size and the legs are way too long. It's always been this way since she was born. She is totally fine and healthy though.

Hope you're ok it's most likely nothing to worry about. It's hard to get the measurements towards end of pregnancy because they are all squashed up.

Hope all goes well at the next scan xxx

With our DD her femurs were measuring several weeks behind the rest of her which really worried me.

She was born a bit early and very petite, but absolutely fine. She has short-ish legs but well within a normal range.... my DH also has a longer torso and shorter legs so she’s just shaped like her dad.

I had this, also with a twin. For me it was the first warning of pre-eclampsia and the plancenta failing. I had extra monitoring and the twins were delivered very early. They are both fine - one of them just has shortish legs!!!

Oh, and what ChikiTIKI said about the onsies!

@Huffleypuff I'm being referred because they're worried the femur is dropping percentiles. They didn't say anything more than that but from googling, restricted growth in arms and legs could be a sign of dwarfism.

Thank you everyone for the support and reassurance. I'm not a natural worrier at all but due to my history I know things can go horribly wrong with babies and pregnancies.

My youngest also has short legs. Her body is on the 50th centile but her legs are 9th. Or they were, she has been taking growth hormones since July and they are now at the 20th. I hope that is all it is, there are many positive stories here x

Thank you @sayitisntsojo
When did your DD have to start taking growth hormones? From birth or when a problem was detected?

I had scans monthly, then fortnightly, then weekly throughout my pregnancy with my twins because one of them was always measuring small. He was born 1lb 5oz smaller than his brother, but 16 months on they're exactly the same size. You'd never know he was born small or 5 weeks early.

Try not to worry, my situation is proof that it can all be OK.

I had this at 31 weeks. They admitted it was really hard to be accurate after 20 weeks in a scan. They kept on about dwarfism etc. When she was born at 33 weeks she was tiny. She weighed 5lb but was very petite all over. They also said that she might not have kidneys- she has the usual amount-2! ( I had my first scan at 31 weeks- surprise pregnancy)
She's 6 now. Like a long legged racing snake. A good 2 inches taller than her friends the same age. I have to buy age 7-8 leggings etc as she is long legged.
We are all unique. IMO this doesn't start at birth it starts at conception so your baby could just be behind in her leg development or they've not been accurate.

Like the girls have basically said, don't take too much notice of the growth. The midwife told me when I was pregnant with my daughter, that she would be lucky to be born alive. They told me she was going to be very small and have major problems because of it. She was born 2 weeks over die and weighed 9lb 8oz. No problems whatsoever. All because they cant measure properly.

I also ad another growth scan which showed that the femur remained on 10th percentile but all other long bones are very small, on or below the 1st percentile. Although the bones in itself look good and the specialist did not see other features of dwarfism I am obviously very concerned now. The head is on 54th percentile and the abdomen on 26th. I am 30 weeks.

Have they given you percentiles for head and abdomen? I had the harmony test earlier which was negative but they did suggest an amniocentesis.

Have they recommandeer any further testing? It’s very unlikely to be Down’s syndrome with a negative harmony test.

*Recommended

There is an average...some are above, some are below

Sorry to hear you are in a similar position @Sunandsea1. Baby's head is on 40th percentile and abdomen also on 40th percentile. From what I've been reading, dwarfism is a concern if the long bones (humerus and femur) are short and the head and tummy are large (like on the 90th percentile) which doesn't seem to be the case for us x

I haven't seen the obstetric ultrasound consultant yet so not sure if they will recommend amniocentesis or further testing.

I'm still absolutely terrified and have made myself ill with worry. I haven't slept at all and I'm an anxious mess.

I had this. They told me he probably just has short legs. Now he's here we know he actually has long legs. I asked about it and the just told me that scans aren't always accurate. I have a high BMI 33 I think which obviously makes it even less accurate.

Thank you everyone for sharing.
I understand you can not exclude most of the skeletal dysplasias via amnio and I would assume it might take weeks before we would get results back now for the most common ones, so really don't necessarily want to risk it. I however already wonder now about the false negative rates of the harmony test and am so worried now that I already (quite unreasonable I guess) question the results as well.
I will be rescanned in 4 weeks.
The only other thing I found on the scan result was a high pi and RI for my left uterine Doppler.
@smokealarm please keep me updated!!! Fingers crossed for your Thursday scan!

Don't panic! My son was measuring 2 weeks behind on his femur, he is 2 now and does not have dwarfism and he is taller than his cousin who is 3!

My dd has had growth hormones from the age of 8, she will continue till 14 or when puberty really kicks in.

Also had this with DS.
I remember googling all sorts!
He actually doesn’t have very long legs but a long torso