I have had a tubal ligation done and I've just found out that I'm pregnant. Can the tubal procedure be reversed so that I can at least try to have this baby?

--A.H.

Tubal ligations, while the best means of preventing pregnancy short of abstinence, are not perfect. The failure rate also tends to increase the longer it has been since one had a tubal ligation. A recent study (the Collaborative Review of Sterilization, or CREST, study) looked at 10,000 women who had undergone tubal ligation and found 143 failures (a failure rate of 1.4 percent). The risk of an ectopic pregnancy (a pregnancy in the tube or otherwise outside the uterus) is also higher if one becomes pregnant after a tubal ligation.

Assuming, however, you do not have an ectopic pregnancy (an ultrasound can determine where the pregnancy is), then you should have no problems carrying this baby to term. Nothing needs to be done beyond routine obstetrical care. If the pregnancy is in the tube, it cannot be saved; surgery must be done to prevent the tube from rupturing, a complication that can be life-threatening.

If you have not done so already, you must see an OB-GYN immediately. It is extremely important to make sure you do not have an ectopic pregnancy. Once an ectopic has been ruled out, you and the baby should do just fine.

In terms of future contraception, you may have your tubes re-tied after the birth, or your partner may have a vasectomy -- or both!