Echocardiographic features and outcomes of fetuses with isolated restrictive foramen ovale or redundant foramen ovale flap using atrial septum excursion index.

Purpose: This study was designed to investigate the application value of the atrial septum excursion index (ASEI) in fetuses with isolated restrictive foramen ovale (RFO) or redundant foramen ovale flap (RFOF) and the outcomes of these fetuses.

Methods: This was a retrospective study. Healthy pregnant women who were examined by antenatal fetal echocardiography from January 1, 2019 to December 31, 2021, at Sir Run Run Shaw Hospital were enrolled. One hundred seventy-seven (177) fetuses were categorized into three groups by diagnosis: (1) RFOF (n = 33), (2) RFO (n = 21), and (3) normal (n = 123). Fetal echocardiographic features and postnatal outcomes were collected.

Results: The median ASEIs were 0.50 (range, 0.41-0.65) in the control group, 0.76 (range, 0.67-0.88) in the RFOF group and 0.31 (range, 0.14-0.35) in the RFO group, and the differences were significant (p < 0.001). The ratios of right atrium/left atrium, right ventricle/left ventricle, and pulmonary artery diameter to aorta diameter (PA/AO) and the pulmonary annulus Z-scores were greater in fetuses with RFOF and RFO than in the controls (p < 0.05). Twenty-seven of 33 fetuses (87.9%) with RFOF and 19 of 21 fetuses (90.5%) with RFO had good outcomes after birth.

Conclusion: The ASEI may be a new tool for quantitatively assessing the mobility of foramen ovale flaps in fetuses with isolated RFOF or RFO.