Depending on other health factors of the patient, odds of succesful reversal can be anywhere from 40% to 90%. You can also freeze some swimmers, which I did long before my vasectomy because I figured freeze 'em while their in their prime.
So can tubal ligations. But the odds are low enough that an objective risk analysis will relegate it to relative unlikelihood. There’s no absolutely surefire birth control, but vasectomies come damn close.
Cheaper than pregnancy. IJS.
