Until ultrasound was invented there wasn’t there anyway for a woman to know if she was carrying conjoined twins, right? Knowing that she’s carrying conjoined twins before birth gives her the chance to abort them. So are fewer sets of conjoined twins born now than before it was possible to detect them in utero?
Weird, this is my night to answer posts about conjoined twins!
It wouldn’t surprise me if ultrasound is helping to spot conjoineds, which may lead to abortions if that’s what the parents want. However, counterbalance this with the increase in the use of fertility drugs, as well as more women getting preggers at older ages – both of which increase the likelihood of multiples, and thus conjoining. Plus, it certainly seems that more conjoineds are surviving what used to be an almost certain early death. Separations are way more successful than they were even just a decade ago.
Okay, so much for pulling guesses out of my hindquarters. Now I’ll do some research: according to Dr. James O’Neill, who’s done nearly two dozen separation operations of conjoineds, the birthrate has indeed decreased, probably due to better ultrasound – but it’s described as only a slight dip. And as I thought, he says that in fact, more conjoined babies are surviving thanks to advances both in pre-natal care and separation techniques.
All in all, sounds like a wash.
But don’t conjoined twins result from one double-, triple-, etc., fertilized egg splitting but not normally? The multiples produced by fertility drugs are fraternal, no? Separately fertilized eggs?