Objective: To evaluate a modified uterine artery score based on the pulsatility index and presence or absence of notching in the Doppler velocity waveform recorded from both uterine arteries in relation to the perinatal outcome.
Methods: A retrospective analysis was performed in 741 third-trimester high-risk pregnancies. The uterine artery score was constructed assigning one point to each abnormal parameter-high pulsatility index and presence of notch-thus ranging from 0 (normal findings in both uterine arteries) to 4 (notch and high pulsatility index in both uterine arteries). In a subgroup with lateral placenta (n = 359), two definitions of abnormal pulsatility index were compared. In the uniform uterine artery score, a pulsatility index > 1.20 in both uterine arteries was considered abnormal, disregarding the placental location; in the subgroup with lateral placenta, the high pulsatility index was defined as > 1.00 on the placental side and > 1.40 on the non-placental side.
Results: Receiver-operating characteristic curves did not reveal any difference in the diagnostic capacity between the group with a uniform uterine artery score and the subgroup with lateral placenta (P = 0.54). In the total material, the odds ratios and linear regression analysis showed an increased risk for an adverse perinatal outcome with increasing uterine artery score (P < 0.01). At a uterine artery score > 2, there was a significantly increased risk for operative delivery for fetal distress, neonatal intensive care unit admission, 5-min Apgar score < 7, preterm delivery and delivery of a small-for-gestational age fetus.
Conclusion: In high-risk third-trimester pregnancies, Doppler velocity waveforms of the uterine arteries can be evaluated using the uterine artery score disregarding the placental location. The uterine artery score possesses a high predictive value regarding adverse perinatal outcome.