Bipolar disorder is one of the most heritable conditions nobody screens for

If you or your partner has bipolar disorder and you're thinking about IVF, chances are the question of whether your child could inherit it isn't new to you. You've probably been thinking about it for years.

Bipolar disorder is one of the most heritable conditions in all of medicine. More heritable than breast cancer. More heritable than type 2 diabetes. More heritable than coronary artery disease. A Finnish twin study of over 19,000 twins put the heritability of bipolar I at 93%. Identical twins showed seven times the concordance rate of fraternal twins.

And yet no IVF clinic in the world routinely offers to screen embryos for it.

That's a pretty remarkable gap. If one parent has bipolar disorder, a child's risk is roughly 10 to 25%. If both parents have it, the odds jump closer to 50%. For families who already know what this condition looks like up close, those aren't abstract numbers. These are parents who have lived through manic episodes, hospitalizations, the slow work of finding the right medication. Many of them have had to weigh the risks of continuing mood stabilizers during pregnancy against the risks of going off them. They already think in terms of probability and tradeoffs. They know exactly what they'd want to reduce the odds of.

So why doesn't anyone offer screening for it? It's not because the science isn't there. The genetic signal for bipolar disorder is strong, and it keeps getting sharper. In 2021, the Psychiatric Genomics Consortium identified 64 genome-wide significant loci for bipolar across nearly 42,000 cases. By 2025, a multi-ancestry study had pushed that to 298 loci across more than 158,000 cases and 2.8 million controls. Fine-mapping is now pinpointing the specific genes involved. We know more about the genetics of bipolar disorder right now than we did about diabetes genetics a decade ago.

The real reason nobody screens for it is structural. Genetic counseling grew up around single-gene disorders like cystic fibrosis and sickle cell. Conditions driven by hundreds of genetic variants just weren't on the menu. And because polygenic psychiatric conditions didn't fit the profession's training, they got treated as if they didn't exist. A genetic counseling professional recently admitted they'd seen "very little about psychiatric disorders" in the field, despite having concentrated on psychiatric conditions in their prior career. That gap between the science and the clinic is where families get left behind.

The screening actually works

When you go through IVF, you produce multiple embryos. Those embryos are biologically siblings: same parents, different genetic combinations. Some carry higher risk for bipolar disorder, some lower. Polygenic embryo screening reads those differences.

The fair question is whether polygenic scores hold up when you're comparing siblings rather than strangers in a population study. Moore et al. 2025 tested exactly this: 17 disease polygenic scores in the sibling context. Sixteen of 17 showed no decrease in predictive performance within families. That's the comparison that actually matters for embryo screening, and the scores hold up.

For bipolar specifically, an Ohio State study following 227 offspring of parents with bipolar disorder over more than 12 years found that polygenic risk scores combined with clinical data predicted new-onset bipolar disorder with an AUC of 0.81. That's a validated predictor, tested in families with bipolar disorder, over more than a decade of follow-up. Not a vague statistical association.

What does this mean in practice? It means that if you have five embryos, their polygenic risk for bipolar disorder won't all be the same. Some will have inherited more of the risk-increasing variants, some fewer. The screening won't tell you with certainty which child will or won't develop bipolar disorder. But it will tell you which embryos carry meaningfully different levels of genetic risk, and for a family that's already making an embryo selection decision, that's information they didn't have before.

Twin studies put the heritability of bipolar disorder at 60% to 80% across subtypes and study designs. The 93% figure is specific to bipolar I, but even the low end of that range is higher than most conditions people already screen for. The genetic signal is there. The tools to read it exist. The question is whether the profession will catch up.

One thing worth noting for families with diverse backgrounds: most polygenic scores were built from European-ancestry data, and psychiatric conditions are among the worst affected by this gap. We calibrate across eight or more ancestry groups because genetic screening should work for everyone who needs it, not just populations that were studied first. For something as consequential as screening for psychiatric conditions, that calibration matters.

The creativity objection doesn't hold up

Some people argue that screening against bipolar risk might screen against creativity or artistic temperament. This comes from a real observation: there is a modest genetic correlation between bipolar disorder and creativity.

But severe bipolar disorder isn't a slightly elevated mood. It's hospitalization, inability to hold a job, fractured relationships. The genetic variants that drive risk for the clinical disorder overlap only partially with whatever underlies creative temperament. And the overlap that does exist is small. Screening reports risk probability for the clinical condition. It doesn't screen out personality traits.

Parents who've actually lived with bipolar disorder know the difference between a productive burst of energy and a manic episode that costs you your marriage. They don't need anyone to explain the distinction.

What you can do about it

For families going through IVF where bipolar disorder runs in the family, the question of genetic transmission isn't something that starts during treatment. It's been there for years, sitting alongside every other decision about medication, stability, and timing. What's new is that there's now a way to get a real answer.

Polygenic screening won't eliminate bipolar risk entirely. But it can tell you which of your embryos carry meaningfully different genetic predispositions, and for a family that has watched this condition reshape someone's life, having that information changes the decision in a real way.

If you'd like to understand what screening can show for your situation, our counselors can walk you through the data. Please reach out to us.