I'm just going to second Sami's point - if you are having the NT screen at the ultrasound, you should have the blood test.

Unless at the scan you plan to say to them "please don't tell me the NT measurement" or "dont measure the nuchal fold", if they measure it, the risk factor they will give you is only 70% accurate. If you include the blood markers then it is 90% accurate. Makes sense to have both.

But if you are saying you want the 12 week scan but don't want the nuchal fold measurement/DS screen, then that's a bit different! Its personal choice - you should stand up for what you want

Congrats on the pregnancy and wishing you a H&H 9 months!!! Hope you find a good carer!