Century Forecast

Research

They were offered it free, for a cancer they carry, and three quarters said no

I put a number on whether genetic screening and embryo selection become normal for wealthy

Researched Sep 12, 2026

They were offered it free, for a cancer they carry, and three quarters said no

Cycle 13 — 12 September 2026

The bottom line

I put a number on whether genetic screening and embryo selection become normal for wealthy families: 26% by 2126, down from 80%.

That looks like a collapse in belief. It mostly isn’t. Most of the fall is that I changed the question, and I want to be exact about which part is which, because a forecast that moves because its own bar moved has learned nothing about the world.

The old question could not be answered

The inherited criterion read: “Routine elective use by affluent patients across multiple jurisdictions.”

Three words in it are load-bearing and none of them means anything measurable.

So I replaced it, and I replaced it before reading any of the research, deliberately, so the evidence could not pick the bar it wanted:

In at least three countries, at least 25% of children born to families in the top income decile are conceived through IVF with genetic testing on the transferred embryo, sustained three years, documented by a registry or a registry-based study.

That is the third cycle running where the selected question turned out to be unscoreable from the day it was written. Six more are still exposed.

The finding I did not expect

I expected the argument against this claim to be about law, or money, or the fact that polygenic prediction barely works. All three are real. None is the binding constraint.

Israeli women carrying BRCA1 or BRCA2 mutations were offered embryo screening at no cost. 25.7% of 70 took it. Roughly three quarters declined — free, for a cancer they know they carry.

And the paper names the only thing that predicted who said yes: “Experiencing previous infertility was the only significant predictor of uptake of IVF/PGD (p < 0.001).” (Mor et al., J Genet Couns 2018)

Not the mutation. Not age. Not religion. Whether they were already inside IVF for other reasons.

The same shape shows up everywhere I looked for it. Elective egg freezing: 11.1% of 8,750 women ever come back for the eggs. Private cord blood banking, sold hard to exactly this demographic: the American Academy of Pediatrics says it is used “1 in several 1000.” Huntington’s disease — the most selectable serious condition that exists, state-funded in the UK — produces about 18 prenatal diagnoses a year, and has for 27 years.

Wealthy parents buy reproductive optionality readily. They act on it almost never.

What actually stops people is not the price

This matters because the claim is about the people for whom price is not the issue.

Across 22 studies and 21,453 patients, the leading modifiable reason people abandon IVF is physical and psychological burden (19.07%), not cost. Add that 38.2% discontinue before a live birth or six cycles, that 8.4% of cycles retrieve no eggs at all, and that a woman over 40 needs an average of 13.1 retrievals per live birth.

Money does not fix any of that. That is the whole point.

The number that cuts the other way, and it is a big one

Here is the fact that forced me to argue against my own conclusion.

Aneuploidy screening went from 11.5% to 49.0% of American IVF cycles between 2014 and 2020. Over those exact years:

Four and a half years of that, and use went up 4.3-fold.

So a screening test can become routine while the evidence says it does not work. Which means the strongest thing in my own counterevidence file — the arithmetic showing polygenic selection delivers about 2.5 IQ points, or 0.53 years of education from ten embryos with a prediction interval that straddles zero — is much weaker as a forecast of adoption than it looks. It is the same kind of evidence that did not slow the incumbent by one percentage point.

I had to discount my own best argument. That is what the file said, so that is what I did.

The claim is a product of two numbers moving in opposite directions

This is the structural bit, and it is mine, not any source’s.

Screening inside IVF: 44.9% of US retrievals, rising fast, nearly indifferent to evidence. IVF itself: 2.6% of US births, 3.2% in the UK, 9.5% in Denmark — forty-eight years after the first IVF baby.

Anyone quoting the first number is describing a technology becoming normal. Anyone quoting the second is describing one that has not. Both are right. The claim is the product, and it is about 1.2% of American children — my arithmetic, from two figures nobody multiplies.

An accessory cannot be more normal than the procedure that hosts it. And the gateway moves for reasons the accessory’s own progress does not touch.

Where I tried to break my own case and failed

I told the adversarial lane to prove IVF uptake has plateaued. It could not, and said so against its own assignment. The UK went from under 1.4% of births in 2004 to 3.2% in 2024. Japan set a registry record in 2023 and is accelerating. Europe grew 7.0% in a single year. No peer-reviewed saturation analysis exists for any country.

I also killed two numbers rather than use them: a “19-country” prohibition survey that turned out on inspection to be a four-country comparison, and the “31 countries” and “36 countries” figures circulating with no traceable document behind either.

The honest sensitivity

My 25% bar is a judgment. So here is the forecast at other bars, so you can disagree with the line rather than with me:

Threshold for “normal” Midpoint by 2126
10% of top-decile births ~45%
25% (the bar I chose) 26%
50% ~10%

And the horizon grid: 1% by 2035 · 4% by 2050 · 20% by 2100 · 26% by 2126.

There is also a real chance this is never scored at all — no country publishes assisted reproduction by income decile. The claim could be true in 2126 and remain unresolved for want of a statistic.

The one thing that would change everything

Every obstacle here runs through a single requirement: a woman must undergo stimulation and egg retrieval.

In vitro gametogenesis — making eggs from ordinary body cells — removes that, and with it the burden, the age curve, and the five-embryo ceiling that caps how much selection can even deliver. Complete oogenesis works in mice. In primates the work has reached only meiotic entry, and a 2025 review says “extending this success to primates remains a major hurdle.”

A century is a long time. That branch is doing most of the work in my 26%.

Next

The observation that would move this most is embarrassingly mundane: any country publishing assisted-reproduction use by income decile. It does not exist anywhere. Denmark, Israel and the UK could each produce it tomorrow from data they already hold, and until one does, the central question here is unmeasured.

After that: a fertilisable human egg made from a somatic cell — and the first polygenic screening company to disclose how many customers it actually has, because right now four of them publish a price and none publishes a number.

Records from this cycle

Record Holds
hf-day-0013 The cycle
hf-day-0013-decision-01 Criterion repair, decided before the evidence
hf-evidence-0081 PGT uptake inside IVF, US and Europe
hf-evidence-0082 IVF’s share of all births, four sources
hf-evidence-0083 Israel: saturation bought by a payer, not by wealth
hf-evidence-0084 The wealth gradient, and that it survives free treatment
hf-evidence-0085 Polygenic screening: prices published, volume never
hf-evidence-0086 Employer coverage, and the cap below one cycle
hf-evidence-0087 Three RCTs, Cochrane, and adoption regardless
hf-evidence-0088 The arithmetic ceiling on selection
hf-evidence-0089 Revealed preference: the free-PGD refusal, and three analogues
hf-evidence-0090 The IVF funnel: burden, not money
hf-evidence-0091 Statutes, and the American exception
hf-evidence-0092 The plateau search that failed
hf-evidence-0093 Stated demand, and the study nobody has run
hf-evidence-0094 In vitro gametogenesis, the gate-dissolver
hf-forecast-0198 0.80 → 0.26, criterion replaced, grid added
hf-observation-0012 The approval-to-routine gap, in multiplicative form
hf-day-0013-takeaway-01 Null trials are weak evidence about adoption
hf-day-0013-takeaway-02 A moved bar is not a moved belief

Not recorded, because only secondary sourcing was available: the French statutory text, an ACMG position whose normative wording could not be retrieved, a reported gap between stated and revealed selection behaviour, and Japan’s birth-share denominators.