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As for the mortality issue, the oldest IVF baby is currently something like 38. And given that it didn’t become common until even later, we’re not going to have

As for the mortality issue, the oldest IVF baby is currently something like 38. And given that it didn’t become common until even later, we’re not going to have that data for several decades. > What a contract says is of little scientific value, unless one is studying tort law and the finer details of butt-covering. They have actual statistics though if not references to the primary sources, so that was more the reasoning.

gwern 9y ago
> As for the mortality issue, the oldest IVF baby is currently something like 38. My point is that a congenital heart defect is something that should strike early, especially in childhood (and that's one of the usual ways to find out about it, kids dropping dead for no good reason, like after being lightly hit in a football game). If a doubling of defects can be detected, so too should a doubling of heart-related mortality. There's on the order of a million IVF kids annually in the USA alone; it's not possible for that to have gone unnoticed. So either their risk is the same as their non-IVF peers and such defects are just common among older mothers, or the defects are not actually serious (pace studies showing that things like cancers or spinal anomalies are common among healthy people, or, more IVF related, that many embryos discarded for chromosomal abnormalities turn out, when implanted, to work perfectly fine because the abnormal cells die or the embryo otherwise recovers during development).
- Alex3917 9y ago
  > it's not possible for that to have gone unnoticed Keep in mind that 93% of heart defects are detectable via an echocardiogram around week 24 of pregnancy. So I would imagine that in most cases where the heart defect is fixable then it's repaired, or else if it's not fixable but also not serious then the kid is just prevented from doing sports. Or else if it's serious and not fixable then pregnancy is terminated. So I would expect the actual mortality to be substantially less than 2x. And given that heart-related mortality in children is extremely rare, I suspect it would be quite tricky to detect. Especially when you need to account for confounding issues like maternal age during pregnancy, ICSI use, etc. Given that there are around 5,000 CHD-related deaths in children per year, and around 1.5% of babies are IVF births, we're talking at most 150 deaths per year instead of 75, probably less due to the reasons mentioned above. And once you start trying to take into account imperfect data confounding variables, it's hard to say whether having definitive proof one way or the other is even within the realm of science at that point.

gwern 9y ago

> As for the mortality issue, the oldest IVF baby is currently something like 38. My point is that a congenital heart defect is something that should strike early, especially in childhood (and that's one of the usual ways to find out about it, kids dropping dead for no good reason, like after being lightly hit in a football game). If a doubling of defects can be detected, so too should a doubling of heart-related mortality. There's on the order of a million IVF kids annually in the USA alone; it's not possible for that to have gone unnoticed. So either their risk is the same as their non-IVF peers and such defects are just common among older mothers, or the defects are not actually serious (pace studies showing that things like cancers or spinal anomalies are common among healthy people, or, more IVF related, that many embryos discarded for chromosomal abnormalities turn out, when implanted, to work perfectly fine because the abnormal cells die or the embryo otherwise recovers during development).

Alex3917 9y ago
> it's not possible for that to have gone unnoticed Keep in mind that 93% of heart defects are detectable via an echocardiogram around week 24 of pregnancy. So I would imagine that in most cases where the heart defect is fixable then it's repaired, or else if it's not fixable but also not serious then the kid is just prevented from doing sports. Or else if it's serious and not fixable then pregnancy is terminated. So I would expect the actual mortality to be substantially less than 2x. And given that heart-related mortality in children is extremely rare, I suspect it would be quite tricky to detect. Especially when you need to account for confounding issues like maternal age during pregnancy, ICSI use, etc. Given that there are around 5,000 CHD-related deaths in children per year, and around 1.5% of babies are IVF births, we're talking at most 150 deaths per year instead of 75, probably less due to the reasons mentioned above. And once you start trying to take into account imperfect data confounding variables, it's hard to say whether having definitive proof one way or the other is even within the realm of science at that point.