Ratio of middle cerebral to umbilical artery blood velocity in preeclamptic & hypertensive women in the prediction of poor perinatal outcome

Abstract

Background & objectives: Doppler velocimetry studies of placental and foetal circulation can provide important information regarding foetal well-being providing an opportunity to improve foetal outcome. The present study was undertaken to evaluate the role of middle cerebral to umbilical artery blood velocity waveform's systolic/diastolic ratio (MCA/UA) and biophysical profile as a predictor of perinatal outcome in hypertensive and preeclamptic pregnant women during the late third trimester.

Methods: Fifty preeclamptic pregnant women selected randomly in the last three weeks of the third trimester were stratified into two groups based on the MCA/UA ratio. All women were evaluated by foetal biophysical profile scoring. Thirty four women with foetal MCA/UA ratios > 1 and 16 with < or =1 were recruited in groups A and B respectively. The results of the ratio, and biophysical profile were evaluated with respect to the outcome of the infants and adverse perinatal outcome, defined as perinatal death, foetal cord blood gas analyses, cesarean delivery for foetal distress, admission to the neonatal intensive care unit, days in the neonatal intensive care unit (NICU) or low Apgar score.

Results: Rate of cesarean delivery was significantly (P<0.001) higher in group B than group A. There was a statistically significant increase in perinatal morbidity in B group. Apgar scores at 1 and 5 min were found to be lower in group B than group A. Umbilical cord blood partial oxygen pressure (pO2), partial carbon dioxide pressure (pCO2) was not different in the two groups; whereas, pH was lower in group B. In group A two neonates (5.9%) and in group B 12 neonates (75%) required admission in neonatal intensive care unit. Best cut-off levels of MCA, MCA/UA ratios were found to be 3 and 1, respectively.

Interpretation & conclusion: The MCA/UA was valuable for predicting the outcome of preeclamptic and hypertensive pregnancies. When the ratio was <1, foetal prognosis was poor.