Comparison of Bishop's score and cervical length in determining the need for cervical maturation before labor induction.

Objectives: The aim of this study is to compare the evaluation of cervical length measured by the Bishop score and transvaginal ultrasonography in determining the need for prostaglandin application for cervical ripening in term nulliparous pregnancies.

Material And Methods: In our study, a total of 120 patients who were admitted to our hospital between February 2015 and August 2015 were divided into two groups as cervical length group and Bishop score group according to hospitalization order by applying the Permuted Block Randomization method, which is one of the Restricted Randomization methods. Each patient included in the study was evaluated with both the Bishop score and transvaginal ultrasonography. Groups were compared according to the APGAR scores in the 1st and 5th minutes, transition within 12 hours, birthing within 24 hours, birthing with only dinoprostone, birthing with only oxytocin, duration of administration of dinoprostone, duration of oxytocin administration, type of birth, rate of cesarean section, and need for neonatal intensive care.

Results: While cervical ripening with dinoprostone was applied to 28 (46.7%) of 60 pregnant women in the Bishop group, labor induction with oxytocin was applied to the remaining 32 (53.3%) pregnant women. In the cervical length group, these values were 33 (55.0%) and 27 (45.0%), respectively. There was no statistically significant difference between study groups in terms of the need for dinoprostone for cervical ripening (p = 0.361). Of those with a Bishop score of 4 or below, 78.6% (n = 22) had a cervical length of over 28 mm, and 71.4% (n = 20) needed oxytocin. Of those with a Bishop score above 4, none of them had a cervical length greater than 28 mm. A statistically significant difference was found between those with a Bishop score of 4 or below and those above 4 in terms of cervical length (p < 0.05). Among those with a Bishop score of 4 or below, the percentage of those with a cervical length above 28 mm was significantly higher than that of those with a Bishop score above 4.

Conclusions: In our study, the delivery time of those with a cervical length of 28 mm and above was significantly higher than those with a cervical length of less than 28 mm, while the bishop score was significantly lower. In order to develop a more objective method that can replace the Bishop scoring system in determining the need for cervical ripening before labor induction, prospective randomized studies that screen larger numbers of patients are needed.