Pregnancy after a tubal ligation is very rare. Only about 1.5% of women who have had tubal ligations get pregnant, and after 10 years, the likelihood of pregnancy increases up to roughly 2%. There are some women who opt to have their tubal ligations reversed because they have changed their minds about wanting children. Even after the procedure is reversed, the chances of getting pregnant are still typically less than they were before the procedure was performed because it normally damages the fallopian tubes to some degree.
Even though it is rare, pregnancy can occur after a tubal ligation because fallopian tubes occasionally grow back together. When this happens, it is possible for the egg to become fertilized and travel down through the reattached fallopian tubes into the uterus, where a baby can develop. Pregnancy after a tubal ligation has a higher risk of being ectopic because of the damaged fallopian tubes. An ectopic pregnancy occurs when the egg does not reach the uterus and instead attaches itself to the walls of the fallopian tubes. Pregnancies like these are incredibly dangerous and occasionally life-threatening for women.
Roughly 10 years after the tubal ligation was performed, a woman's chances of conceiving increase slightly. This is because, by this time, the fallopian tubes will have had a chance to grow back together after being separated. This almost never happens, and when it does, it typically means that the procedure was not performed properly to begin with. The fact that human error is always possible means that tubal ligation is not necessarily a guaranteed method of birth control for any woman, although pregnancy is rare enough that most women are content to take their chances.
Medical professionals can reverse tubal ligations for women who change their minds about having children. The reversal can be expensive, however, and there is no guarantee that conception will be possible afterward. Pregnancy is much more likely if the procedure is reversed, but women who have had the reversal may still be at higher risk for an ectopic pregnancy and might experience some difficulty conceiving. Roughly 1 in 100 women who have had the procedure reversed may have ectopic pregnancies, and the chances of conception tend to be greater for women under the age of 40.