Middle cerebral artery peak systolic velocity, ductus venosus velocity waveforms and gestational age at delivery in the prediction of perinatal mortality in IUGR fetuses

Abstract

A preliminary study suggested that a high middle cerebral artery peak systolic velocity (MCA-PSV) and reversed flow (RF) in the ductus venosus (DV) are good predictors of perinatal mortality (PM). In IUGR fetuses, the effect of gestational age (GA) at delivery on PM has not been well investigated. The aim of this study was to compare the performance of MCA, DV, umbilical artery (UA) Doppler and GA at delivery in the prediction of PM in IUGR fetuses. The study population consisted of 38 IUGR fetuses [EFW <3rd percentile, and an umbilical artery pulsatility index (PI) >95% confidence interval] in which the last Doppler studies were performed at a median interval of 1 day (range 0 to 3 days) before delivery or fetal demise. MCA-PI and PSV, DV-PI, and UA-PI were considered abnormal when they fell above (MCA-PSV, DV-PI, and UA-PI) or below (MCA-PI) their normal reference ranges. The presence, absence (A), and RF of DV and UA were also determined. A T-test for independent groups, Chi-square or Fisher's exact-test, and logistic regression were used for the analysis. P < 0.05 was considered statistically significant. GA at delivery ranged between 23.1 and 32 weeks (median 27.6 weeks). Birth weight ranged between 240 and 1240 grams (median 470 grams). There were 17 perinatal deaths (16 deaths occurred in fetuses delivered at < 29 weeks). No fetus survived when delivered at a GA <25 weeks. Fetuses that died were at a significantly lower GA at the time of delivery than those who survived. The forward Wald stepwise logistic regression indicated that two parameters predicted the PM (R2 = 53): (a) the combination abnormal MCA-PSV/DV-ARF and (b) GA at delivery. Between 25 and 29 weeks there was a reduction in perinatal mortality of 47% per gestational week. GA at delivery and the combination abnormal MCA-PSV/DV-ARF in preterm IUGR fetuses were the best parameters in predicting PM. The decreased PM gained for each week that IUGR fetuses remain in-utero should be taken into account when a decision to deliver an IUGR fetus at < 29 weeks is made.