Determining cervical ripeness and labor outcome: The efficacy of magnetic resonance T2 relaxation times

OBJECTIVE: To determine whether the magnetic resonance assessment of cervical water content using the T2 relaxation time correlated with cervical ripening, as evidenced by the time to onset of spontaneous labor, need for induction, and the incidence of cesarean delivery in women whose pregnancy reached 41 weeks of gestation. METHODS: The cervical T2 relaxation time was calculated from magnetic resonance data obtained in a previous study of magnetic resonance pelvimetry. After consent was obtained, the patients underwent a magnetic resonance imaging (MRI) protocol consisting of a dual fast spin echo T2-weighted scan. From images of a single slice, the cervical T2 relaxation time was calculated from two different regions of interest (anterior and posterior) on the cervix. The average cervical T2 relaxation time was then correlated to obstetric outcomes linked with cervical ripening. RESULTS: A total of 119 patients gave their consent for the study. Of these patients, 93 had optimal imaging of the cervical stroma and were included in the analysis. There was no significant correlation between the cervical T2 relaxation time and any individual component of the Bishop score or the total score. The cervical T2 relaxation time did not predict whether labor was spontaneous or induced and whether or not a woman underwent cesarean delivery. CONCLUSION: Cervical magnetic resonance T2 relaxation times did not correlate with the clinical Bishop score or predict labor outcome in our series of women whose pregnancies reached 41 weeks of gestation. Quantifying the magnetic resonance T2 relaxation time does not appear to be useful in the assessment of cervical ripening.