Sterilization as Part of Sentencing

Assuming there was enough precision to control the duration of a sterilization, so that it would expire after a certain time, why not as a condition of a criminal sentence take away a person's ability to reproduce? This would include penalties against those criminals who had the foresight to freeze their eggs and sperm in advance - any person who assisted in using that material to create an embryo would be guilty of an offense. Similarly it would be an offense to attempt to reverse the sterilization prematurely.