20 wk scan measurements

[Lolly2803]

Hi ladies,
I had my 20 wk scan today and I am expecting fraternal twins.
While structurally everything looked great and normal and their growth although on the smaller side of normal was still normal. But Twin 1's femur bone was slightly outside the normal range and measuring a bit smaller. They have referred us to the fetal medicine unit and we are seeing them next week.

Of course I am now super worried! Has anyone else experienced anything like this? I am attaching a picture of my measurements as well incase anyone else has anything similar or knows more than me about all this! Thanks ladies. Xxx

Same thing has happened to my sil with her twins.

Not sure what he measurements mean but advice is, rest and up your protein intake.

Hope your baby catches up xx

This is nigh on identical to my situation when I was having my fraternal twins, now 10 weeks old. Twin 2 always measured behind twin 1, everything within normal centile apart from the femur which consistently measured behind and off the little line chart just the same as yours. Not sure if it will help but ill tell you our experience (positive ending) which started at the 12 week scan firstly showing twins but then twin 2 had an increased NT of 6.1mm and we were rushed into that room of doom and dished all the worst case scenario stuff about what it might mean and also given info about going down the selective reduction path. We weren't going to just accept this without further investigation n we were referred like you to fetal medicine unit. To cut a long story short we refused amnio as we didn't want to risk the pregnancy but did go down the non invasive route and had a NIPT which showed a les than 1:1,000,000 risk of the 3 syndromes the NHS screening told us twin 2 had a 1:14 chance of having, i.e down/Edwards/Pattau syndrome. I had weekly scans at FMU each one showing twin 2 was growing consistently but always behind twin 1 and the long bones were measuring short but were growing. A scan at 16 weeks picked up that twin 2 had bilateral talipes, clubfoot which they again tried to suggest it was linked to some chromosomal problem because of the initial increased NT and small measurements but didnt know what. We still didnt want the amnio. Things progressed on to week 29 when the risk from amnio changed from miscarriage to pre term labour which we then decided to have the test to either confirm or rule out any other issues so i had it at just short of 30 weeks and the full results came through all normal. We had some issues with umbilical blood flow so the babies were delivered by elcs as both breech at 34+4. Twin 2 yes his arms n legs are a bit shorter than twin 1 but not obviously so and he is having treatment for clubfeet but apart from that he is just little. Looking back thru my close family history, the males down my dads side are all short, my brother dad and grandad all short arses so although his growth is being monitored, the chances are hes just little like his uncle, grandad and great grandad.

Thanks never a shadow! Makes me feel so much better to hear positive stories. Must have been such a worry for you though. Hope you were able to enjoy your pregnancy.

We've had an NIPT test called Serenity which tests for Downs, Edwards and Patau and it came back "no abnormality detected" and the risk from NHS was 1:9,100 for Downs and 1:50,000 for the others. Everything else on the scan was normal and looked great. Trying to keep positive! They are so active and the scan took 2.5 hours so I'm hoping they were just too active for the measurement to be accurate!

Let's see what they say today. xxxx

Hi Lolly,

Please keep us updated, there is another thread her with a similar story, but the sonographer actually asked the mother is there a family history of "shorter Men" in her family, which there was. She was induced and it was found that the smaller twins placenta was unhealthy, so the baby is just catching up outside the womb.

I am expecting twins and like you like to arm myself before the scan. My placenta in anterior so will be having a scan at 21weeks.

Hi all,

Dr appointment well as well as it could. She checked everything on both babies again and the only thing outside of normal was Twin 1 Femur length. She said that it's normal for twins to be a bit small and for one to be smaller than the other. She said it can be a soft marker for Down Syndrome but with all the results and the NIPT coming back fine/low risk and no other indicators that would be extremely unlikely so that's basically ruled out. She said that this is likely just normal for twin 1 and that what was important was the growth curve and that is why I will have lots more scans with there being twins.
She also said it can be an early indicator of the placenta not functioning properly later but for now it was absolutely fine.
She didn't mention this but it was in my notes - dwarfism. Apparently it can be a sign of that but there would be other markers and Twin 1 doesnt had any of those so that too is super unlikely.

She didn't seem worried and next scan will be as planned at 24 weeks and she said she'll do it.
I feel better about it and just hoping Twin 1 grows as she/he should do!

Hope you're all ok xxx

Oh lollly that's great news :)