Whether or not an unwanted pregnancy will occur after several years of not going for a checkup after a ligation needs to be assessed based on the effectiveness of the ligation, and a successful ligation has a very low chance of pregnancy after the operation. There are two types of ligation surgeries, one for the male vas deferens and one for the female fallopian tubes. Ligation can be divided into surgical severance, medication ligation, etc. Generally speaking, the vas deferens and fallopian tubes will be cut off or blocked after the ligation, so that there is no possibility for sperm and egg to meet in order to achieve the effect of contraception. The probability of pregnancy after successful ligation surgery is extremely low. Generally, there is no need to review the condition after ligation if there is no infection or other discomfort. If the operation is not effective and the tubes are not fully ligated, unwanted pregnancy may occur, and you can consult the operating hospital for details of the operation.