I read with great interest the letter of Professors S.M.M. Karim and S.S. Ratnam (October 19, p.161) on cervical rupture during abortion induced by intraamniotic prostaglandins (PGs). The authors state rightly that this type of trauma is secondary to excessive uterine stimulation in the presence of unusual cervical resistance and that it is encountered mainly in young primigravidae. The lesion, however, is not limited to patients given PGF2alpha; cases have already been reported after intraamniotic instillation of PGE2. It is therefore unlikely that the latter compound exerts any protective action in this respect. It is necessary to point out that 2 very different lesions are encountered. The 1st occurs at the level of the thinned out posterior isthmic wall before any cervical dilatation has taken place. It presents as a transverse tear through which fetus and placenta are expelled into the vagina. The tear may extend into the lateral aspects of the isthmic region, leading to partial annular detachment of the cervix. Even when repaired, this lesion may fail to heal and a fistulous tract may develop which interferes with later reproductive performance. The complication can be prevented by examination of the cervix at regular intervals during the course of abortion and, in those cases at risk, by insertion of 1 or more laminaria tents into the cervical canal. In cases of impending rupture, gentle instrumental dilatation of the cervix should be performed immediately. Very different and of less consequence is the longitudinal tear involving the lateral aspect of an insufficiently dilated cervix during expulsion of the conceptus. This lesion, somewhat comparable to a Duhrssen's incision, is easier to repair and, if it does not reach the uterine isthmus, should not be a cause of cervical incompetence. To the best of my knowledge, not a single instance of either type of traumatic lesion to the cervix has been reported after extraamniotic administration of PGs. It is possible that the Foley catheter, usually utilized with this route, has a "ripening effect" on the cervix which facilitates dilatation.
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