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Objective: Prenatal congenital heart disease classification systems distinguish between critical dextro-transposition of the great arteries (d-TGA) with restriction of the foramen ovale (FO) (which requires a Rashkind procedure within the first 24 h following delivery) and d-TGA for which surgery is planned (after prostaglandin perfusion or Rashkind procedure later than 24 h after delivery). However, current prenatal diagnostic criteria for postnatal FO restriction in d-TGA are inadequate, resulting in a high false-negative rate. We aimed to identify echocardiographic features to predict the urgent need for Rashkind procedure.Methods: We identified retrospectively 98 patients with singleton pregnancy diagnosed prenatally with fetal d-TGA at two European centers from 2006 to 2013. Two groups were compared: (1) those in whom the Rashkind procedure was performed within the first 24 h postnatally; and (2) those who did not undergo a Rashkind procedure before cardiac surgery. Exclusion criteria were: (1) no fetal echocardiography within 3 weeks prior to delivery (n = 18); (2) delivery before 37 weeks of gestation (n = 6); (3) improper or lack of measurement of pulmonary vein maximum flow velocity (n = 10); (4) lack of neonatal follow-up data (n = 9); (5) Rashkind procedure performed more than 24 h after delivery (n = 4).Results: Fifty-one patients met the inclusion criteria: 29 who underwent the Rashkind procedure and 22 who did not. There were no differences between these two study groups in terms of maternal age, gestational age at time of fetal echocardiography, fetal biometric measurements, estimated fetal weight, rate of Cesarean delivery, newborn weight or Apgar score at 1 min. There were also no differences during prenatal life between the two groups in terms of fetal cardiac size (heart area/chest area ratio), rate of disproportion between left and right ventricle, FO diameter and maximum velocity of flow through the FO. However, the pulmonary vein maximum velocity was significantly higher in the group requiring a Rashkind procedure (47.62 ± 7.48 vs 32.21 ± 5.47 cm/s; P < 0.001). The cut-off value of 41 cm/s provided maximum specificity (100%) and positive predictive value (100%) at only a slight cost of sensitivity (82%) and NPV (86%). The prenatal appearance of the FO also differed between the groups, the FO valve being flat in 52% of those requiring a Rashkind procedure.Conclusions: In fetuses with d-TGA, prenatal sonographic findings of increased pulmonary venous blood flow and flattened FO valve were associated with the need for a Rashkind procedure within the first 24 h postnatally; these echocardiographic features could be used to predict prenatally a need for the procedure following delivery. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Abstract Objectives Based on the assumption that the horizontal area between the fetal foramen ovale valve and the atrial septum (the outlet) represents the limiting structure for the foramen ovale flow, our objective was to determine the normal size of this section during the second half of pregnancy. Methods One hundred and thirty-eight women with low-risk singleton pregnancies were examined in a cross-sectional study between 18 and 42 weeks of gestation. Using ultrasound imaging and M-mode, the area and diameter between the foramen ovale valve and the atrial septum were determined in a four-chamber view of the fetal heart above the foramen ovale limbus. The inferior vena cava cross section and right atrial width were also determined. Results The mean foramen ovale width increased from 3 mm at 18 weeks to 6 mm at term. Correspondingly, the horizontal area grew from 15 to 50 mm2. The mean ratio between this area and the area of the inferior vena cava fell from 1 at 18 weeks to 0.5 at term. The ratio between the transverse width of the foramen ovale and the right atrium remained at average 0.45–0.50 until 32 weeks, when a slight reduction was observed towards term. Conclusions Normal values for the horizontal cross section and transverse diameter of the foramen ovale outlet were established for the second half of pregnancy. In particular, the horizontal transverse diameter and its ratio to the right atrial width are easy to determine, and use of these measurements is thus suggested for the assessment of the fetal foramen ovale. [ABSTRACT FROM AUTHOR]