Prediction and prevention of preterm birth after cervical conization

Cervical pessary for the prevention of preterm birth: is it of any use?

Preterm birth (PTB) represents a heavy burden in modern obstetrics as it is a major cause of perinatal morbidity and mortality. After the introduction of transvaginal sonography (TVS) screening, secondary prevention of PTB has been re-evaluated on the basis of pre-existing cervical length (CL) and meanwhile the cervical pessary has become an object of increasing interest. This device consists of a silicone cone acting mechanically, that can be easily placed or removed, but whose efficacy is still controversial. Therefore, this study aims to review the most recent evidence regarding its efficacy for prevention of PTB, together with the correct position, the evidence regarding the mechanism of action, the exclusion criteria for pessary placement and the reasons for precocious removal. Overall, it is well tolerated and there are no reports on severe associated side effects. Finally, we discuss published data regarding cervical pessary efficacy. Although results are still conflicting, it seems however to be an effective method for preventing PTB, both in singleton and multiple pregnancies, but further evidence is needed.

Is Early Treatment with a Cervical Pessary an Option in Patients with a History of Surgical Conisation and a Short Cervix?

Objective: Patients with a history of one or more conizations have an increased risk of spontaneous preterm birth (SPTB). The aim of this study was to investigate the outcome of pregnancies in patients with a history of conization and early treatment with a cervical pessary. Methods: In this pilot observational study we included 21 patients and evaluated the obstetric history, the interval between pessary placement and delivery, gestational age at delivery, the neonatal outcome and the number of days of maternal and neonatal admission. Results: Among the study group of 21 patients, 20 patients had a singleton and one had a dichorionic/diamniotic twin pregnancy. At insertion, the mean gestational age was 17 + 2 (10 + 5-24 + 0) weeks and the mean cervical length was 19 (4-36) mm. Six patients presented with funneling at insertion with a mean funneling width of 19.7 (10-38) mm and funneling length of 19.9 (10-37) mm. Five patients had already lost at least one child due to early spontaneous preterm birth and another five had at least one previous abortion, who have now delivered beyond 34 weeks. The mean gestational age at delivery was 38 (31 + 1-41 + 0) gestational weeks and the mean interval between insertion and delivery was 145 (87-182) days. Conclusion: Our findings suggest a beneficial effect of an early pessary placement for patients at high-risk for preterm birth due to conization.

Cervical pessaries for prevention of spontaneous preterm birth: past, present and future

This Review describes the rationale for the use of cervical pessaries to prevent spontaneous preterm birth and their gradual introduction into clinical practice, discusses technical aspects of the more commonly used designs and provides guidance for their use and future evaluation. Possible advantages of cervical pessaries include the easy, 'one-off' application, good side-effect profile, good patient tolerance and relatively low cost compared with current alternatives. Use of transvaginal sonography to assess cervical length in the second trimester allows much better selection of patients who may benefit from the use of a cervical pessary, but future clinical trials are needed to establish clearly the role of pessaries as a preterm birth prevention strategy worldwide.