Hugs. I'm sorry you are going through this. Our story is a little convoluted, but here it is:
I also had an ultrasound at 9 weeks pregnant, for size and dating. We learned that the baby had a cystic hygroma (CH) - a collection of fluid behind the neck. We were told that this could be a sign of a chromosome disorder and there was a strong chance the baby would not live past the 2nd trimester. We were referred to a high risk specialist for additional tests and counseling.
It took a little bit of time and work to find a high risk specialist I was comfortable with. Because of our religious beliefs, there were certain options we would not consider and I needed a doctor who would respect that. Once we found the right specialist, he set up a series of level 2 ultrasounds to monitor the CH. My husband and I choose not to have invasive prenatal testing done. (I'm not against the testing itself, but skipping it was the right choice for us.)
By the start of the 2nd trimester, the CH had started to shrink. By the 20th week ultrasound, the CH had resolved and there were no signs of fetal abnormality.
My son was born at 41.5 weeks, 8lbs, and healthy. We were overjoyed. He had (and still has) a very small growth on the back of his neck, but it's barely noticeable.
DS had signs of having neurological differences from early on, but he was our first (only) and we did not recognize these issues. He was unable to nurse and had a lot of feeding problems throughout infancy and toddlerhood. He missed his speech milestones, social milestones, and motor milestones. At age 2 he could read, but could not talk. A week after he turned 3 he was diagnosed with high functioning autism with hyperlexia and dyspraxia.
No one can tell us if DS's autism is related to the CH he had in utero. Last year we had some chromosome testing done and discovered that DS has a microdeletipn on the 19th chromosome. This is a very rare finding, so rare that the doctors do not know the clinical significance of it.
Additionally, we learned that DS has a form of albinism, which results in a mild visual impairment. Albinism is a genetic recessive trait, so DH and I have to both carry the gene, although neither of us knows of any family history of the disorder. It is believed that the albinism is unrelated to DS's other challenges.
So DS truly has a unique medical history and we never know what to expect with him. He is now 7 and has made great progress. We are very lucky to live in a school district with excellent services and wonderful teachers and therapists. He is a happy, smart, funny little boy and is the light of our lives.
I wish all the best to you and your family.