124: The role of the contraction stress test in deliveries with oligohydramnios

Abstract

To examine the implementation of the contraction stress test (CST) to decide the mode of delivery in pregnancies with oligohydramnios. Retrospective cohort study. Once labor induction was indicated, CST was performed to all women from 34 gestational weeks with oligohydramnios (AFI<5cm) between 2005-2011. Women with abnormal CST (i.e positive or equivocal), underwent cesarean delivery (CD) without a trial of labor and those with negative CST had a trial of labor. Patients' flow chart is described in the figure. Among 1221 patients with oligohydramnios, a CST was performed in 987 patients (80%). Eighteen patients (1.8%) were operated on due to the CST results without a trial of labor. The rest (N=969; 98.2%) were allowed a trial of labor. Significant risk factors for abnormal CST were primiparity, increased gestational week and IUGR fetuses (table). Among the negative CST cases, 95 (11%) delivered by CS. of them, 78 (69%) women were operated on due to non reassuring fetal monitoring. Seventy (90%) women were operated on in the latent phase, while only 6 (8%) and 2 (3%) women were operated on in the active phase and second stage of labor, respectively. Negative CST in oligohydramnios is associated with favorable delivery outcome, particularly once the woman has entered the active phase of labor. It is a poor predictor for fetal compromise during labor in women with oligohydramnios, however, it may be beneficial when oligohydramnios is associated with primiparity, increased gestational week or IUGR fetuses.View Large Image Figure ViewerDownload Hi-res image Download (PPT)