[Cervical cerclage--when is it effective?]

To compare the effectiveness of the different types of cervical cerclage (primary, secondary and tertiary) for prevention of preterm deliveries and second trimester abortions.

The study is retrospective, including 145 pregnant women with history and/or clinical signs of cervical incompetence. In 86 cases cervical cerclage has been performed while in the remaining 59 cases management has been expectant. Among the patients with cerclage 57 had primary, 25 had secondary and 4--tertiary cervical suture. In 21 cases cervical length was measured by transvaginal ultrasound. In 9 cases cervical length was < 25 mm and in the remaining 12 cases-- > or = 25 mm.

Cervical suture placement and expectant management were found to be equally effective in patients with indications for primary cerclage. On the contrary, in patients with indications for secondary cerclage mean gestational age at delivery and the percentage of patients that remained undelivered after 34 w.g. were higher in the subgroup that had cerclage compared to the one that was treated expectantly. In patients with indications for tertiary cerclage pregnancy outcome was similar in the subgroups with and without cerclage and in general was unfavorable. Gestational age at delivery was higher if the cerclage was placed before 18 w.g. and if cervical length was > or = 25 mm.