Is there an association between sonographically determined occipito-transverse position in the second stage of labor and operative delivery?

Objective. To evaluate if ultrasound-determined occipito-transverse position early in the second stage of labor is associated with operative delivery. Design. Retrospective review of two prospective cohort studies. Setting. An Australian tertiary referral hospital. Population. Women with term, cephalic singleton pregnancies. Methods. Retrospective analysis of data from two prospective studies. Logistic regression was undertaken to assess the independent contribution of the occipito-transverse position to operative delivery. Main outcome measure. Operative delivery (cesarean section, forceps or vacuum extraction). Results. Among 422 women included, the occipito-transverse position was present in 80, occipito-anterior in 303 and the occipito-posterior in 39. Compared with occipito-anterior, the adjusted odds ratio for operative delivery was 2.1 (95% confidence interval 1.2-3.8, p = 0.02) for the occipitotransverse position, and 7.4 (95% confidence interval 3.2-17) for the occipitoposterior position. Factors that independently predicted operative delivery were nulliparity, abnormal second stage cardiotocography, maternal place of birth and epidural analgesia. The length of second stage of labor was longer for the occipito-transverse group than for the occipito-anterior group (median 2 h 7 min vs. 1 h 36 min, p = 0.003). Conclusion. The occipito-transverse position early in the second stage of labor was associated with an increased operative delivery rate.