Ask The Doctor: Repeated Cryos... Health Article

Joan Bengtson, M.D., is assistant professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and a member of the Department of Obstetrics, Gynecology & Reproduction at Brigham and Women's Hospital.

Question:

Does repeated cryosurgery pose a threat to a woman's fertility?

Answer:

Cryosurgery is a technique for treating precancerous lesions on the cervix. The tissue is frozen by applying a solution of liquid nitrogen. The abnormal cells are destroyed, allowing the cervix to heal with healthy tissue. Other ways to destroy, or ablate, abnormal cells are with a laser or by electrocautery.

An alternative to ablation treatment is to remove the abnormal tissue by a technique called excision. Excision can be done with a scalpel ("cold knife" cone biopsy), an electric current ("LEEP" procedure) or laser excision. Excision procedures usually damage more normal tissue than ablation treatments, but they are also more reliable in removing the abnormal cells.

Surgery on the cervix can threaten fertility and pregnancy outcomes. If too much normal tissue is damaged, the cervix may be weakened. The cervix may fail to stay closed during pregnancy, resulting in miscarriage, preterm delivery and low birth weight. This condition, called cervical incompetence, is treated by placing a stitch around the cervix. Cervical incompetence is rare, but more commonly seen after excision techniques than ablation procedures.

Cervical surgery can also cause scarring, resulting in narrowing or stenosis of the cervical canal. Stenosis may be treated by dilating the canal to allow passage of sperm and menstrual fluids. Stenosis is more common after ablation procedures, but it is also an unlikely event.

The risks associated with cervical surgery are significant, so caution is used in deciding when treatment is necessary, especially in young women still anticipating future pregnancies. On the other hand, the ability to identify precancerous cervical disease with Pap smears and treat it before progression to a life-threatening stage is obviously important and balances the risks.