Foramen Ovale Pulsatility Index as an Early Affected Doppler Study among Abnormal Growth Fetuses: A Recent Insight for Practice Based on a Prospective Study.

Background: Routine Doppler study is a common tool for early diagnosis of Fetal Growth Restriction (FGR) and Small for Gestational Age (SGA) patients. It aimed to determine the role of the Foramen Ovale Pulsatility Index (FOPI) study beside routine Doppler study among patients with FGR and SGA fetuses.

Methods: This prospective study was conducted on 35 FGR, 32 SGA, and 33 Appropriate for Gestational Age (AGA) fetuses. Demographic data, amniotic fluid index, neonatal outcome, and Doppler velocimetry, including Umbilical Artery Pulsatility Index (UMAPI), Uterine Artery Pulsatility Index (UTAPI), Middle Cerebral Artery Pulsatility Index (MCAPI), Ductus Venosus Pulsatility Index (DVPI), and FOPI were documented. Kolmogorov-Smirnov normality test, one-way ANOVA, Mann-Whitney U, Kruskal-Wallis, non-parametric pairwise comparisons adjusted for Bonferroni correction, Pearson correlation test, Chi square, Fisher's exact test, and Receiver Operating Characteristic Curve (ROC) analysis with Youden's Index (sensitivity+specificity-1) to estimate cut-off point were used to analyze the data at significance level <0.05 for all tests.

Results: FOPI cut-off points were 2.24 (sensitivity=77%, specificity=94%) and 1.15 (sensitivity=90%, specificity=20%) to predict FGR and SGA, respectively. FOPI showed a positive correlation with UMAPI and UTAPI (r=0.52 and r=0.30, P<0.001 and P=0.006, respectively), but not with MCAPI and DVPI (r=0.08 and r=0.12, P=0.50 and P=0.30, respectively). Besides, UMAPI, UTAPI, and FOPI were altered among patients with stages I and II FGR. Umbilical cord potential hydrogen (umbilical cord pH), 1- and 5-min Apgar score significantly increased by Birth weight centile; however, UMAPI, FOPI, and UTAPI significantly decreased.

Conclusion: UMAPI is recommended to predict short-term neonatal morbidities and demonstrate the early or late onset FGR. Besides, FOPI is suggested as the first-line Doppler study to detect abnormal growth velocity. More studies are warranted, especially considering long-term neonatal morbidities.