A study of horses—which share many important similarities with humans in their chromosomes and pregnancies—revealed that 42% of miscarriages and spontaneous abortions in the first two months of pregnancy were due to complications from an extra set of chromosomes, a condition called triploidy. A study of horses—which share many important similarities with humans in their chromosomes and pregnancies—revealed that 42% of miscarriages and spontaneous abortions in the first two months of pregnancy were due to complications from an extra set of chromosomes, a condition called triploidy. Veterinary medicine Phys.org – latest science and technology news stories