Operations for cervical incompetence.

At present, cervical cerclage is indicated in those patients with a classic history of cervical incompetence. For the majority of these patients, a postconceptional cerclage procedure is better suited because it is done after the fetus has been evaluated ultrasonographically for obvious abnormalities and after the risk for spontaneous abortion is past. The greatest experience is with the Shirodkar and the McDonald procedures; allowing for operator differences, neither appears to have an important advantage. The transabdominal cervicoisthmic cerclage may be a useful postconceptional procedure in the selected patient whose cervix is either markedly foreshortened, deeply lacerated, or infected. Preconceptional cerclages are best reserved for those rare patients in whom a markedly foreshortened incompetent cervix is associated with early second-trimester pregnancy losses (preconceptional isthmic cerclage) or in whom the cervix has a single, identifiable scar or deep laceration extending through the internal os (Lash procedure).