This will impel people to make love and bring more new lives.

I hereby declare this a threat to planet Earth. We're already reaching carrying capacity, we don't need people fucking for coins!

In this futuristic society each woman is sterilized after giving birth to two childs so there is no risk for overpopulation.

Interesting. This opens up a black market for cloning and desterilization tools. Which could be bought using DNA-coin. This coin feeds itself..

Yes with the result of overpopulation, starvation and eventually colonization of other planets (Mars?)