Prognostic value of foramen ovale morphology and hemodynamics in late-onset fetal growth restriction: a 3D ultrasonography-based study.

OBJECTIVE

To assess the structural and hemodynamic characteristics of the foramen ovale (FO) in fetuses with late-onset fetal growth restriction (LO-FGR) using three-dimensional (3D) ultrasonography and Doppler imaging, and to examine their associations with Doppler parameters in FGR and composite adverse perinatal outcomes (CAPO).

METHODS

This case-control study included 40 fetuses with LO-FGR and 40 matched controls exhibiting appropriate-for-gestational-age (AGA) between 34 and 37 weeks. FO area was measured using 3D spatio-temporal image correlation (STIC) imaging, and FO width and pulsatility index (PI) were evaluated using 2D and Doppler ultrasonography. FO parameters were compared between the groups, and partial correlation analyses adjusted for gestational age to assess their associations with FGR and CAPO. Additionally, Receiver Operating Characteristic (ROC) curve analysis was conducted to evaluate the predictive value of FO parameters for CAPO within the FGR group.

RESULTS

FO area (p < 0.001), FO width (p < 0.001), left atrial (LA) width (p = 0.029), FO/LA ratio (p < 0.001), and FO/RA ratio (p = 0.024) were significantly reduced in the FGR group compared to the controls. Among FGR fetuses, those who developed CAPO had lower FO area (p = 0.009), FO width (p = 0.001), LA width (p = 0.006), FO/LA ratio (p < 0.001), and FO/RA ratio (p = 0.041). In ROC analysis, the FO/LA ratio exhibited the highest predictive value for predicting CAPO (AUC: 0.851, p < 0.001).

CONCLUSION

Alterations in FO morphology are significantly associated with adverse perinatal outcomes in LO-FGR. The FO/LA ratio may serve as a reliable and noninvasive parameter for risk stratification. Incorporating advanced fetal cardiac morphometry could improve prenatal surveillance in FGR.