Value of interior vena cava Doppler waveform analysis for prediction of neonatal outcome

The objective of this article is to determine the value of the inferior ven a cava preload index (IVC) to predict neonatal outcome and compare it to ot her biophysical methods of antenatal surveillance. A clinical outcome study of patients referred to the author's institution for Doppler velocity bloo d flow studies was undertaken by comparing the ability of three antenatal s urveillance tests: the nonstress test (NST); umbilical artery S/D ratio (UA ); and the ratio of the middle cerebral artery to umbilical artery S/D rati os (MCUA) to predict poor neonatal outcome to the ability of the IVC to pre dict poor outcome. Patients were followed serially and neonatal outcome dat a was tabulated. Those patients that delivered within 10 days of their last study were included in the analysis. Seventy patients met the inclusion cr iterion, Neonatal outcome based on the results of the IVC as compared with outcome based on the results of the NST, UA, and MCUA tests. Odds ratios (w ith 95% confidence limits) for significant neonatal morbidity predicted by each test were: NST: 2.6 (0.14-14.6); UA: 5.7 (1.7-18.8); MCUA: 3.6 (1.1-13 .1); and IVC: 4.1 (1.3-13.2). Logistic regression analysis indicated that t he combination of MCUA and IVC was the best method of predicting poor neona tal outcome. This study of the utility of fetal IVC suggests that this noni nvasive method of antenatal surveillance may provide an additional sensitiv e method of evaluating the status of the high-risk fetus.