Short femurs 35 weeks

[Worried23]

Hi. I had a growth scan at 33 weeks, during which the abdominal measurement was beyond the 95th percentile, but the femurs were much lower, measuring a couple of weeks behind.

I have now had a growth scan at 35 weeks, and the femurs have grown only another 2MM to 65MM and have dropped further down the percentiles to about 10th (and about 2 or 3 weeks behind). The abdominal measurement has settled down and is more 75th percentile now.

Whilst the sonographer/doctors say not to worry, I literally cannot stop worrying and looking into it online. I think I assumed we'd have the 35 week growth scan and the femurs would have caught up but clearly they are dropping behind.

I am not sure what this means, and I am getting increasingly worried that the baby will continue this pattern and that there is a problem with a genetic abnormality. The estimated weight is very good which seems to be a reason they are not worried.

This is my first and I'm anxious as it is so any advice is appreciated.

Hi, sorry to hear you are so anxious. This happened to me in my last pregnancy. I went for a growth scan at 34 weeks and femurs were measuring in the 3rd centile. I was convinced my baby had either a chromosonal issue or dwarfism. Happily he was born perfectly healthy and now at 4 months is in the 25th centile for length.

From my understanding it's very difficult to get accurate measurements so late in pregnancy and if the femur measurement was normal at 20 weeks then there is ussally nothing to worry about.

My daughter had exactly the same measurements. We had a couple of growth scans but her legs were always on the 2nd centile.

She is now 8, completely perfect but she is short. Not abnormally so but one of the smallest girls in her year group. She is in proportion but has a long torso and short legs.

We assume she will take after her 5ft nothing Grandma.

Try not to worry although it is hard. My husband was devastated and honestly thought she would be affected with a form of dwarfism.

My very tall baby showed short femur lengths on every growth scan with her abdomen and head on the upper ranges. She came out big and long and at almost 3 months is comfortably in 3-6 month clothes and the length is already getting tight! I asked the specialist about it a few times and he said femur length is the hardest one to measure and a few mm can mean the difference between the 10th to the 80th centile. Try be positive. It is most likely totally fine