The role of abnormal cerebroplacental ratio in predicting adverse fetal outcome in pregnancies with scheduled induction of labor.

OBJECTIVE

To investigate the role of abnormal cerebroplacental ratio (CPR) in predicting adverse fetal outcome in pregnancies with induction of labor.

METHODS

This prospective observational study conducted at Medeniyet University Göztepe Training and Research Hospital between December 1, 2018 and October 31, 2019 enrolled women with scheduled induction of labor at or beyond 37 weeks of pregnancy. Women with singleton non-anomalous fetuses with cephalic presentation and who had Bishop scores of 5 or less in pelvic examination were included in the study. Exclusion criteria were the presence of uterine scar history, non-cephalic presentation, multiple pregnancy, vacuum- or forceps-assisted delivery, and shoulder dystocia. Using fetal Doppler ultrasound, CPR was calculated (the ratio of umbilical artery to middle cerebral artery pulsatility index) and categorized into abnormal CPR (<1) and normal CPR (≥1). Data on maternal and delivery characteristics, fetal birth weight, and fetal complications were compared between the groups.

RESULTS

A total of 145 women were included, 28 in the abnormal CPR group and 117 in the normal CPR group. Multivariate analysis revealed labor induction at a later week of pregnancy (odds ratio [OR] 10.33, P = 0.001), lack of intrauterine growth restriction (IUGR) (OR 13.21, P = 0.001), fetal distress (OR 8.14, P = 0.003) or meconium aspiration (OR 159.91, P = 0.001), and umbilical artery pH values greater than 7.31 (OR 17.51, P = 0.015) to be associated with an increased likelihood of having normal (≥1) CPR values. Receiver operating characteristic analysis revealed association of normal CPR values with later labor induction (cut-off value of >38.3 weeks, P = 0.001), higher birth weight (cut-off value of >2460 g, P = 0.022) and higher umbilical artery pH (cut-off value of >7.31, P = 0.007).

CONCLUSION

Our findings revealed the significant role of abnormal CPR in predicting adverse fetal outcome in singleton pregnancies with scheduled induction of labor.