Complex sentence: Most cases of aneuploidy result in termination of the developing fetus, however there can be cases of live birth; the most common extra chromosomes among live births are 21,18 and 13.
Split into simpler sentences: Most cases of aneuploidy result in termination of the developing fetus however there can be cases of live birth. The most common extra chromosomes among live births are 21,18 and 13.