Amniotic-Umbilical-to-Cerebral Ratio – A Novel Ratio Combining Doppler Parameters and Amniotic Fluid Volume to Predict Adverse Perinatal Outcome in SGA Fetuses At Term

Abstract

Purpose Introduction of a novel ratio – the amniotic-umbilical-to-cerebral ratio (AUCR) – to predict adverse perinatal outcome in SGA fetuses at term and comparison of its predictive accuracy with established parameters. Materials and Methods This retrospective cohort study included 165 singleton pregnancies with SGA fetuses (birth weight < 10th percentile) at term. Cases with planned vaginal delivery and documented pulsatility indices (PI) of the umbilical artery (UA), middle cerebral artery (MCA), and single deepest pocket (SDP) were included. CPR was calculated as the ratio between MCA PI and UA PI, UCR as the ratio between UA PI and MCA PI. AUCR was defined as follows: SDP/(UA PI/MCA PI). Adverse perinatal outcomes were defined as operative intervention (OI), OI due to fetal distress, admission to the neonatal intensive care unit (NICU), and composite adverse perinatal outcome (CAPO). Associations between Doppler parameters and these outcomes were estimated using regression analyses. Results OI was statistically significantly associated with UCR, SDP, and AUCR, whereas no association was observed for UA PI, MCA PI, and CPR. Fetuses requiring OI due to fetal distress revealed a significantly higher UA PI and UCR as well as a lower MCA PI, CPR, and AUCR. With regard to NICU admission and CAPO, a significantly higher UA PI and lower CPR were found. Furthermore, a significant association was shown for SDP, UCR, and AUCR. AUCR achieved the best area under the curve for all outcome parameters. Conclusion AUCR leads to an improvement in the prediction of unfavorable outcome in SGA fetuses at term. Furthermore, results of our study show that UCR might be superior to CPR.

Combination of Doppler measurements with amniotic fluid volume for the prediction of perinatal outcomes in fetal growth restriction

“…We found that, among the other single Doppler parameters, only the UA PI was a good predictor for APOs; MCA PI and UtA PI were not significantly different for APOs. This result is similar to the study by Stumphe et al 20 and we think that only UA PI is useful for predicting APOs in FGR pregnancies. The UtA Doppler measurement may be useful in pre‐eclamptic pregnancies, but it is not valuable for FGR fetuses.…”

“…Finally, the AUCR = SDP / UCR (UA PI/MCA PI) decreases in term FGR fetuses. Stumphe et al 20 first studied the AUCR and claimed that it was superior to single Doppler measurements, such as UA PI, MCA PI, and UtA PI, and was also superior to Doppler ratios, such as CPR and UCR. These results are similar to our findings.…”

“…Referring to a previous study, the sample size of the current study was determined by G* power 3.1. with a = 0.05 and b = 0.15, respectively, and the minimum number of patients required to obtain 85% power was calculated as 100. 20,26 Windows SPSS software version 25 (IBM) was used for the statistical analyses. Normally distributed continuous variables were compared using Student t test, and Mann-Whitney U test was used for nonparametric variables.…”

“…Finally, for the first time in the literature, Stumpfe et al described the combination of the SDP into the UCR as the amniotic‐UCR (AUCR), and concluded that this ratio of SDP to UCR as the AUCR might have a higher predictive accuracy in APOs. Furthermore, they stated that an adequately powered randomized trial is needed to address this issue 20 . Therefore, we planned a prospective study of AUCR to compare its predictive value for APOs with other confirmed Doppler measurements, CPR and UCR, within a population of women with suspected FGR at term.…”

“…Furthermore, they stated that an adequately powered randomized trial is needed to address this issue. 20 Therefore, we planned a prospective study of AUCR to compare its predictive value for APOs with other confirmed Doppler measurements, CPR and UCR, within a population of women with suspected FGR at term.…”