There is a procedure called "tubal ligation reversal" for women who have undergone a tubal ligation and afterwards decide to become pregnant. This procedure can be performed for several reasons and several factors are considered before the procedure: the type of tubal ligation procedure originally performed, the age of the woman (in your case, above 40 years you should consult your health provider), and how the damage created by the original tubal ligation correlates to the success of the tubal ligation reversal. If tubal ligation reversal is not possible, then in vitro fertilization is the next procedure you might consider. You may consult your gynecologist for further examinations and advice.