Scan measurements behind what they should be - would you be worried by these measurements?

[KatyH]

I had an anomaly scan at 17+3 weeks but looking at my notes they have put the gestation at 16+2 weeks. I know the date of conception and know that the 17+3 is correct so I charted the different measurements and they are all less than they should be:

Head circumference = 124mm (16+5 weeks)
Abdominal circumference = 106mm (16+4 weeks)
Femur length = 19mm (15+4 weeks)

The consultant didn't even mention this so presumably didn't think it was a cause for concern but isn't this quite a way out, especially the femur length?! This is the one that worries me the most as I know it is a soft marker for other anomalies.

The scan was booked primarily to check for neural tube defects so I am worried they might not have been paying too much attention to other things.

Has anyone experienced anything similar?

Scans aren't very accurate ime. I had a growth scan at 36 weeks with DD, and all her measurements were 2nd centile or below. 5 weeks later, out comes a 10lb 5oz baby!!

I'm sure they would have said something if they were worried. Maybe you should phone your midwife for reassurance, just to put your mind at rest.

IME scans weren't very accurate either. With DS I was told I would birth an elephant. He was 6lb 1oz, although very healthy.

Is it perhaps that measurements are about averages? If your baby was way outside the average measurements they'd probably let you know.

I had my dating scan at what I believed to be 15+4. I told the scan MW (not a sonographer) that's how far along I thought I was.

The head circumference was 17+0w
The other two measurements were 15+4w and 16+4w

The MW used the 17w measurement as her preferred measurement (she could only use one to confirm due date) and that brought my due date forward by 10 days, which means that either she is wrong (which means then that pressure to induce will start on what I believe is my actual due date) or I ovulated ridiculously early for me. I know what my money is on.

I don't think those measurements are that far out. I mean the first two are about 4 days out, which isn't much.

Babies start growing according to their genetic predisposition after 12 weeks anyway, so they are all different sizes.

As for the femur length, my baby's head measured slightly below average but his femur length was nearly off the chart at 20 weeks.

I wouldn't worry about it.

Thanks for the reassurance. I think I am just a little paranoid as they questioned IUGR with DD1 and down's syndrome with DD2...yet I'm sure there femur lengths were never that far out.

I hate scans and measurements. They cause nothing but anxiety!