Intra-observer variability of Doppler measurements in umbilical artery (UA) and middle cerebral artery (MCA) in uncomplicated term pregnancies.

Objective: To evaluate the intra-observer variability of the middle cerebral artery (MCA) and umbilical artery (UA) Doppler measurement taken under optimal conditions in term, uncomplicated pregnancies. Methods: A prospective study on uncomplicated singleton term pregnancies was performed. Multiple Doppler measurements were taken in the MCA and the UA by one examiner. Intra-rater agreement was calculated. Doppler indices were correlated to fetal biometric parameters and to gestational age. Results: One hundred patients were recruited. MCA indices were found to have the highest strength of intra-rater/observer agreement (K = 0.888) versus only a "good" agreement for UA pulsatility index (PI) (K = 0.755).The MCA-PI was significantly correlated with BPD (r = −0.198, p =.047), EFW (r = −0.241, p =.01) and birthweight (r = −0.208, p =.03). A statistically significant decrease was found in the MCA PI (r = −.422, p <.001) and in the CPR (r = −0.444, p <.001) with advancing pregnancy, between 37 and 42 weeks gestation. The UA PI did not change significantly (p =.099) during this period. Conclusions: MCA PI measured at term is reproducible with a high ICC. MCA PI significantly decreases with advancing gestation at term. No correlation was found between Doppler measurements and time to delivery. [ABSTRACT FROM AUTHOR]