I just found out the pregnancy I lost had mosaic (14%) monosomy 21 with complete homozygosity and suspected rescue. Some googling led me to learn that autosomal monosomies cause only 0.6% of miscarriages while autosomal trisomies cause 35%. And apparently a mosaic monosomy is even rarer. And the rescue thing is even more rare. I'm just curious what all these rare things generally mean and why they are so rare? I was just really expecting a trisomy in the report and I'm kind of thrown off now.