Q&A: An extra membrane was seen on my ultrasound indicating chromosomal abnormalities.

It's not clear you mean by an "extra membrane." You need to get a more precise description. For example, did they mean an extra fold of skin in the nape of the neck of the fetus? This feature is mostly seen in the first three months of pregnancy and if beyond a certain width, could be associated with a chromosome abnormality such as Down syndrome. A very precise measurement however is necessary by someone who is really trained and experienced. The technical term for this finding is an increased nuchal translucency. Do you think this is what the doctor meant? If so, an amniocentesis for prenatal chromosome studies would hopefully provide reassurance or a precise diagnosis.