Objective: To evaluate cervical length in twin pregnancies measured by transvaginal ultrasono- graphy. Design: A prospective clinical study. Setting: Department of Obstetrics and Gynecology, Medical Faculty of Palacky, Olomouc, Czech republic. Methods: Clinical data of cervical length in twin pregnancies measured by transvaginal ultraso- nography were summarized. Results: 69 % of patients delivered after 36 th week of gestation, mean gestational age at the time of delivery was 35.5 week. Mean cervival length measured bi-weekly from the 16 th till 34 th week was 34.9, 34.6, 33.8, 33.2, 29.7, 28.7, 29.1, 28.4, 23.6, 22.8 mm. The creation of the funneling was recorded in more than 80 % of patients with preterm delivery at the mean gestational age 23 week. Mean cervical length in patients delivered before 36 th week was in the 23 rd week of gestation 21.5 mm, while in woman delivered near term was average cervical length 33.1 mm. Genital infection in patients with preterm labours was present in 27 %. Conclusion: Transvaginal ultrasonography seems to be a useful method in antenatal care of risk pregnancies with twins.

        Key words: twins, transvaginal ultrasonography, preterm delivery