Predictive value of middle cerebral artery to uterine artery pulsatility index ratio in preeclampsia

Abstract

To determine the predictive value of middle cerebral artery (MCA) to uterine artery pulsatility index (PI) ratio in preeclamptic patients. This prospective cross-sectional study was performed on 64 preeclamptic and 131 normal pregnancies at or beyond 26 weeks of gestation between June 2007-August 2008 in the high-risk pregnancy unit of Dr. Zekai Tahir Burak Women Health Teaching and Research Hospital, Ankara. Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was measured. The ratios between the PI of MCA and the mean PI value of both uterine arteries were calculated and values below the fifth percentile were considered as brain-sparing. The ratios between the PI of MCA and PI of the umbilical artery were calculated and values lower than 1.08 were considered as brain-sparing and the results were related to perinatal outcome. Statistical analysis were performed using the SPSS Software (SPSS, Chicago, IL, USA) version 9.0 for Windows. Odds ratio with 95% confidence interval (95%) was also used for statistical analysis. In 11 (42.3%) of the preeclamptic pregnancies that had abnormal MCA/uterine artery PI, 4 of them had severe preeclampsia and 7 had mild preeclampsia. In the low MCA/uterine artery PI ratio group, a statistically significantly higher rate of Cesarean section (66 vs. 88.46%), NICU admission (26.3 vs. 57.6%), preterm birth (52.6 vs. 92.3%) was found. Abnormal MCA/uterine artery PI ratio and abnormal MCA/umbilical artery PI ratio in the prediction of adverse outcome of pregnancy was compared. In the prediction of preterm birth, which was better for the MCA/uterine artery, there was a significant difference between the ratios (P = 0.005). Our results suggest that MCA/uterine artery PI ratio is a good predictor of neonatal outcome in preeclamptic patients in the third trimester and could be used to identify fetuses at risk of morbidity and mortality.