Implications of training for pessary placement and accuracy of cervical length measurements after pessary placement: A prospective, double-blind, randomized clinical trial

Background: Cervical pessary placement as an intervention for preterm birth prevention in women with a short cervix is a simple, painless procedure with few complications and a reasonable cost. Its efficacy depends on the expertise of the obstetrician performing the procedure. Therefore, it is reasonable to assume that untrained obstetricians with no expertise in pessary placement are more likely to insert the pessary incorrectly, thereby reducing its efficacy. Nevertheless, the impact of pessary placement expertise and training, as well as the accuracy of cervival length measurements, has never been evaluated.

Objective: To evaluate the impact of providing training for pessary placement to obstetricians with no expertise in this intervention. To this end, the percentage of correct pessary placements and accuracy of cervical length measurements after pessary placement achieved by obstetricians who received such training was compared with the results achieved by obstetricians who did not receive any training.

Methods: This prospective, double-blind, randomized clinical trial included 91 pregnant women requiring a cervical pessary due to a short cervix. Patients were assigned at random to a group treated by untrained obstetricians with no expertise in pessary placement (untrained group, n = 45) or to a group treated by trained obstetricians with no expertise in pessary placement (trained group, n = 46). The primary outcomes were the quality of pessary placement and the accuracy of cervical length measurements after pessary placement.

Results: Obstetricians in the trained group achieved a significantly higher percentage of correct pessary placements than obstetricians in the untrained group (97.8 % and 65.2 %, respectively; p < 0.001). No significant differences were observed between groups in terms of the accuracy of cervical length measurements after pessary placement (p = 0.661), and both groups showed moderate to good agreement with the expert's measurements (intraclass correlation coefficient 0.840 and 0.749, respectively). No differences in pregnancy outcomes were observed between groups.

Conclusion: This study showed that providing training in pessary placement to obstetricians with no expertise in this procedure increases the quality of pessary placement. Furthermore, the inconsistent results found in pessary studies may be explained, in part, by a lack of training in pessary placement.