Objective. To investigate the relation between changes in Doppler parameters of fetal and uterine arteries and development of persistent non-reassuring fetal heart rate (FHR) pattern during induction of labor with dinoprostone (Propess®) in pregnancies at ≥41 weeks gestation. Design. Prospective cohort study. Setting. Etlik Zubeyde Hanim Women's Hospital, Turkey. Sample. One hundred forty-one prolonged pregnancies. Methods. Doppler parameters of umbilical, middle cerebral, and uterine arteries were measured before and 46 hours after dinoprostone application between uterine contractions. Non-reassuring FHR pattern and persistent non-reassuring FHR pattern criteria were defined based on NICE 2007 guidelines. Women with successful spontaneous vaginal delivery were recruited as a control group (n=108), while women who underwent cesarean delivery due to persistent non-reassuring FHR pattern were recruited as a study group (n=15). Main outcome measures. Prediction of non-reassuring FHR pattern with Doppler analysis of uterine and fetal arteries. Results. After dinoprostone application there was significant enhancement in uterine artery resistance index (RI) in the study group compared to the control group (p=0.002). Receiver operating characteristics curve analysis identified a uterine artery RI increase value of 0.11 as the optimal threshold for prediction of persistent non-reassuring FHR pattern with 73.3% sensitivity and 69.4% specificity. Logistic regression analysis demonstrated that an increase in the uterine artery RI was predictive for persistent non-reassuring FHR pattern (odds ratio (OR) 4.97; 95% CI 1.516.8). Conclusion. Acute increase in uterine artery RI due to dinoprostone use may end with persistent non-reassuring FHR pattern in prolonged pregnancies. This may allow earlier prediction of persistent non-reassuring FHR pattern development and risk assessment. © 2009 Informa UK Ltd.