Objective: To compare digital and ultrasonographic cervical examination for the prediction of preterm delivery in patients hospitalized for preterm labor.
Study design: Fifty-nine patients were included. The Bishop score was evaluated upon admission, weeks gestational age. Ultrasonographic measurement of cervical length was done within 24h after entry. Delivery before 37 weeks gestational age was the primary endpoint. Attending obstetricians were blinded to the results of echography.
Results: Preterm delivery rate was 39% (23/59). The risk of preterm delivery was significantly increased when the Bishop score was greater than or equal to 6 (OR = 4.45 [1.41-14.01]) or when ultrasonographic cervical length was less than or equal to 27 mm (OR = 4.04 [1.32-12.3]), but digital examination was the only independent risk factor in multivariate analysis. Sensitivity, specificity, positive and negative predictive value for digital examination and ultrasonography were respectively 74, 61, 55 and 79%, 70, 64, 55 and 77%. Combination of digital examination and ultrasonography did not yield better results.
Conclusion: In our series, prediction of preterm delivery was not improved by ultrasonography compared to digital examination. The size of the cervical shift observed in most patients hospitalized for preterm labor may render ultrasonography less relevant in identifying patients anticipated to deliver prematurely.