NT Scan...how late is too late?

[Junglemum]

You can't have an accurate nuchal scan at 20 weeks......

The thickening on the back of the neck dissipates over time, thus giving an inaccurate/false scan result. Pretty sure 16 weeks is too late for a NT test. The time frame is somewhere near 13-14 weeks.

The blood test test doesn't have the same time constraints. So you could just have that done. But the highest accuracy is when both tests (combined with your age) are done and risks are calculated.

[SweetPea]

I recently had my NT scan, from my earlier dating scan I was 12 weeks and 5 days, but was measuring 13 weeks and 5 days when I had the NT scan, she said that she may not be able to do it - she said it is alot harder as the baby is more developed and moves around alot more making it much harder for them to get an accurate measurement. She did manage, but it took a long time as the baby was moving alot and was very insistent on lying on its tummy cuddled up to the placenta!

[LimeSlice]

Yep from what I have found we have missed the boat...but not too concerned really, from what people say it isn't exactly the most accurate test regardless. Spoke with DH last week, explaining to him what it was etc, and he said that it wouldnt matter anyway as he is completely not ok with having a CVS done if anything is shown up - so not much point getting the scan if we arent prepared to have the follow up tests if anything is wrong I suppose.

Will get the bloods done anyway though.

Thanks again ladies!

[HotI]

There are 2 different blood screens you can get done- 1st trimester screening is the one done in conjunction with the NT scan.

2nd trimester maternal serum screening is a blood test taken between week 14 to 20 (optimal 15-17 weeks) and gives you a risk value for trisomy 21, trisomy 18 and neural tube defects such as spina bifida. If you get bloods taken before week 15, you may not get a caculated risk for neural tube defects.