A Modest Proposal for your 2024 New Years Resolution: Freeze Your Sperm

Egg freezing is increasingly normalized in certain social groups — but sperm freezing is still considered weird. Egg freezing is seen as a potentially necessary accommodation to the professional timelines of women — but it is still expensive & risky. In contrast, sperm freezing is >10x cheaper and completely risk-free. Frozen sperm does not result in any increased risk for children conceived using the sperm, and sperm from older fathers makes sicker kids. Pairing sperm freezing with a vasectomy is the cheapest, safest, & most effective birth control strategy. Now, I doubt that everyone tomorrow will start banking sperm… but why aren't more people talking about this?

Old Dads Have Much Less Healthy Kids, and the Problem is Old Sperm:

Studies have consistently shown that children conceived by fathers over the age of 40 face a 30% increase in the risk of chromosomal disorders. This risk escalates with age, presenting a series of health challenges:

• Fathers >40 have a 30% increase of chromosomal disorders
• 14% increased risk of preterm births when fathers are born over age 45, 14% more likely to be in the NICU, 18% more likely to have seizures.
• Weirdly, men over 45 give their partners a 28% increased risk of gestational diabetes during pregnancy.
• More likely to have heart defects.
• Cleft palate, cataract, esophageal atresia, diaphragmatic hernia, encephalocele or coarctation of the aorta all also increase.
• Significant autism increase — and that risk is permanent — your grandchildren will also have increased risk. A 50 year old father has a 2x increase in autism vs a father at 30.
  • this is likely driven by de novo copy number variations (CNVs)
• bipolar is 50% more common when fathers are >55 years of age vs 25 years of age. mother's age has no impact (note — do bipolar people father children at 55 more often? Maybe?)

The root of these increased risks lies in the nature of sperm production. Sperm continually replicates throughout a man's life, multiplying the chances for replication errors, epigenetic changes, and de novo mutations:

• It is estimated that spermatic chromosomes are replicated 35 times by age 15, 150 times by age 20, 380 times by age 30, 610 times by age 40, and 840 times by age 50.
• every year a father gets older, you see ~2 more de novo mutations..) Women's age does not increase de novo mutations (because the cells do not divide). The father's age expalins 94% of the observed mutation rate.

Run, Don't Walk, to Your Nearest Fertility Clinic

Maybe consider freezing your sperm. It's cheap. It's easy. Maybe it's even fun? Unlike egg freezing, freezing sperm doesn't lock you into needing IVF. And your kids will be healthier (and happier?) being conceived from your healthy young sperm. You can do it at most fertility clinics, and IVF is a cash market — so no dealing with insurance.

One final note — if you're under 25, hold off on listening to all of the above, at least for a few years. if you're under 20, you have a 38% increased chance of chromosome disorders!