Cerclage: Shirodkar, McDonald, and Modifications.

As the concept of cervical insufficiency has evolved from a poorly defined clinical/anatomic entity into 1 component of the spontaneous preterm birth syndrome, so have cerclage applications. Originally developed to treat history-defined cervical insufficiency and acute cervical insufficiency, cerclage is now utilized on a larger scale for the prevention of recurrent spontaneous preterm birth. As its role expands, the need for prospective data evaluating cerclage techniques and modifications is emphasized. Herein, we will review the techniques, modifications, risks, efficacy, and evidence-based applications of the cerclage procedure in contemporary clinical practice.