Reversible Male Contraception With Gold Nanorods

MTorrice writes "Men's options for birth control have significant downsides: Condoms are not as effective as hormonal methods for women, and vasectomies require surgery and are irreversible. Doctors and scientists have for decades searched for more effective and desirable male contraception techniques. Researchers in China now propose a nonsurgical, reversible, and low-cost method. They show that infrared laser light heats up gold nanorods injected into mice testes, leading to reduced fertility (abstract) in the animals."

Comments

The problem is statistics

[dargaud]

If a contraception method is 99.9% effective in its effect on procreative cells, for a female it means that out of the 500 eggs she may produce in her life, maybe one has a 50% chance to be fertilized (if taken at the right time, etc). Acceptable risk. For a male, it means that out of the 300 millions sperms contained in the average ejaculation, there will still be 300 thousand standing up in lines at Egg's door. That's one of the reasons why it's much more difficult to design a male contraceptive.

Re:The problem is statistics

[Anonymous Coward]

Out of 300 million, 2/3 come out dead or swim in circles. Out of those, maybe a few thousand make it through the cervix. Then maybe 100 or so make it into the fallopian tubes. If the egg popped out more than a day ago, it's no good, and if it's not there yet, the half life of those few sperm is about a day.

So eliminating 99.9% from the start is pretty effective, given that a normal healthy couple only has about a 1 in 5 chance of conception in any month.

Perspective on this changes a lot between being a teenager terrified of getting the girlfriend pregnant to being a late-30's married man, hoping baby #2 will come after spending years and big money on fertility treatments to get baby #1.