How rare are identical quadruplets? Brisbane woman gives birth to 1-in-15-million babies

Identical quadruplets happen when a single fertilized egg splits multiple times in the womb, which is incredibly rare compared to fraternal multiples that come from separate eggs. The odds are genuinely astronomical - way less than 1 in 15 million for it to happen naturally, so that Brisbane woman basically won the world's wildest lottery!

Don't confuse identical quads with fraternal ones - fraternal is way more common since it's just multiple eggs getting fertilized, but identical quads are genuinely wild because they all come from a single fertilized egg that splits multiple times, which is super rare and honestly not totally understood by doctors even today. The splitting has to happen at just the right moments during early development, and if it doesn't split evenly or at the right stage, you end up with conjoined twins or other complications instead. That 1-in-15-million number floats around, though exact odds are hard to pin down since it's so uncommon that we don't have tons of data on it. Medical records show only a handful of cases worldwide, so this Brisbane case is legitimately remarkable.