Is there any relation between development of persistent non-reassuring fetal heart rate pattern and acutely increased uterine artery vascular flow resistance during dinoprostone use in prolonged pregnancies?

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 >or=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 4-6 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 1.5-16.8).

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.