Radiographic findings in cervix uteri after prostaglandin abortion induction.

Hysterography was performed on 173 nulliparous patients following termination of midtrimester pregnancy by intra-amniotic prostaglandin F2 alpha (PGF2 alpha). In 21 hysterograms (12%) a pathologically wide internal os was found, compared with three out of one hundred routine hysterograms carried out for infertility examination. A deformed cervical canal with filling defects and synechiae was found in the hysterograms of 28 patients (16%). Only one of the 6 patients with ruptured cervix had a wide internal os. A laminaria tent was inserted more frequently into the cervix of patients whose internal os was of normal wide. The clinical picture of patients and the courses of abortion inductions did not differ in other respects in patients with normal vs. wide internal cervical os. This leads us to believed that there are two types of cervix: a rigid, hypoplastic cervix with high collagen content, which when exposed to the trauma of abortion induction leads to rupture, but not necessarily to incompetence, and a softer type of cervix, very muscular, which leads to wide internal os and incompetence.