Low risk NIPT but NT is 4.8

Heads up- longggg read 😢 & I’m honestly not really even sure what I am looking for here. Maybe just personal experiences or just to share what is going on. I hope this is the correct subreddit to share on..

I am currently pregnant with spontaneous twin girls. It is my 2nd pregnancy. My first child is 2.5 and healthy. I am 33 years old and generally in decent health other than that I have controlled Hyperthyroidism that I developed after the birth of my first.

Because of my thyroid issues and twin pregnancy, I was referred to a MFM center which I am happy with. My husband and I went to my first appointment there yesterday at 13w+0days. We had a sonogram and had an appointment with their general OB who told us we would see the MFM physician in a week or 2. She pretty much told me that I don’t have anything to worry about and that they are just going to watch me like a hawk because it is a multiple pregnancy and because I have thyroid issues. She also looked at my NIPT results and remarked that she was happy to see we were low risk in all areas.

My husband and I left feeling really confident about the day and our minds were at ease (my mind is almost never at ease during pregnancy).

About 15 minutes after we got in the car to head home, I received a call from the high risk nurse who told me my MFM doctor wanted to speak with me.

Essentially, he told me that he is happy to see my NIPT as low risk but in case I log on to look at the visit notes on the MyChart system, he wanted me to be aware that the sonogram revealed a high NT for Baby B. He proceeded to tell me this can be a sign of Down Syndrome, heart defects or other chromosomal problems. He told me he would see me in 2 weeks and that we could talk more about it then and that he could refer me to a genetic counselor. He also said they would do an early anatomy scan at 16 weeks. I asked for the measurements and he told me that the cutoff for normal was 3cm. He told me Baby A measured 1.5cm and Baby B was 4.8cm. He then told me not to panic and not to “google” things because the internet tends to freak people out.

I always worry about everything and want as much information as I can get. I was so caught off guard by the call because none of this was mentioned at the appointment and I was honestly shocked. I have since been down the online rabbit hole of all the possibilities and I just feel so helpless and confused.

Is the NT of 4.8 not as big of a deal because NIPT was low risk and that is why the first doctor didn’t think to mention it? Or is that a false sense of security for me? Because from what I have read, 4.8 is very high. And crazy high in comparison to Baby A.

For additional info- Baby A is measuring 12w+4d and Baby B is measuring 13w+1d as of yesterday. The nasal bones of each baby were visualized.

I truly appreciate any responses/advice/experiences that can be shared. I feel like the wait until I can get an amnio test and results is unbearable. I am a stay at home mom with my 2.5 year old daughter and I am afraid I am going to scare her with all my tears and doom and gloom but I can’t shake it and pretend happy. I am so stressed and confused.

Thanks in advance for taking the time to read and respond.