If you're a woman interested in preserving your fertility window beyond its natural close in your late 30s, egg freezing is one of your best options.

The female reproductive system is one of the fastest aging parts of human biology. But it turns out, not all parts of it age at the same rate.

The eggs, not the uterus, are what age at an accelerated rate. Freezing eggs can extend a woman's fertility window by well over a decade, allowing a woman to give birth into her 50s. In fact, the oldest woman to give birth was a mother in India using donor eggs who became pregnant at age 74!

In a world where more and more women are choosing to delay childbirth to pursue careers or to wait for the right partner, egg freezing is really the only tool we have to enable these women to have the career and the family they want.

Given that this intervention can nearly double the fertility window of most women, it's rather surprising just how little fanfare there is about it and how narrow the set of circumstances are under which it is recommended.

Standard practice in the fertility [...]

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Outline:

(05:12) Polygenic Embryo Screening

(06:52) What about technology to make eggs from stem cells? Wont that make egg freezing obsolete?

(07:26) We dont know with certainty how long it will take to develop this technology

(07:48) Stem cell derived eggs are probably going to be quite expensive at the start

(08:36) Cells accrue genetic mutations over time

(09:12) How do I actually freeze my eggs?

(12:12) Risks of egg freezing

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First published:
February 8th, 2026

Source:
https://www.lesswrong.com/posts/dxffBxGqt2eidxwRR/the-optimal-age-to-freeze-eggs-is-19

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Narrated by TYPE III AUDIO.

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Images from the article:

Graph showing monthly probability of pregnancy ending in birth by male partner age.

Monthly probability of getting pregnant for couples not on birth control. Note that these couples weren't actively trying for pregnancy, which is why the absolute probability is so low. See figure A4 from Geruso et al. for context.

Yes, you're reading this right. SART literally does not distinguish between 20 year olds and 34 year olds in their success metrics.

This figure was generated with a model built by embryo selection company Herasight. You can read their whitepaper on the model's construction here __T3A_LINK_IN_POST__

These calculations use numbers from Herasight's IQ predictor and assume both parents are of European ancestry. The benefit is slightly smaller for parents of east and south asian and african ancestry. Everyone would like to fix this but we need more data from non-European ancestries to do it.

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“The optimal age to freeze eggs is 19” by GeneSmith

LessWrong (30+ Karma)

“The optimal age to freeze eggs is 19” by GeneSmith