If you're a woman interested in preserving your fertility window beyond its natural close in your early 40s, egg freezing is one of your best options. But if you rely on your doctor to tell you when to freeze them, you will likely be doing yourself and your future prospects for a family a disservice.

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 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 industry is to wait until a woman reaches her mid to late 30s, at which point if she isn't on track to have all the children she wants, it's advised she freeze her eggs.

This is not good practice. The outcomes from egg freezing decline in a nearly linear fashion with age, and conventional advice does a great misservice to women by not encouraging them to freeze eggs until it's almost too late.

The optimal age to freeze eggs varies depending on the source and metric, but almost all sources agree it's sometime between 19 and 26.

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.*

So why has the fertility industry decided to make "freeze your eggs in your mid-30s" the standard advice as opposed to "freeze your eggs in your sophomore year of college"?

Part of the reason is fairly obvious: egg freezing is expensive and college sophomores are not known for being especially wealthy. Nor is the process especially fun, so given a choice between IVF and sex with a romantic partner, most women would opt for the latter.

But another reason is that the entire fertility industry is built around in...

Robyn Mays

Robyn Mays

Robyn Mays

Robyn Mays