3.2 Neonatal outcomes
Neonatal outcomes are summarized in Table 3. Eighteen neonates (37.5%) required urgent BAS, immediately after birth (n=13, 27.1%), on the first day after delivery (n=4, 8.3%) and on the second day after delivery (n=1, 2.1%).
On prenatal echocardiography, only 3 of 13 fetuses requiring urgent BAS immediately after birth had VSD. In these 13 fetuses, the median FO diameter was 5.1 mm (IQR 1.6). Of four fetuses requiring urgent BAS on the first day of life, only one had VSD. In these 4 fetuses, the median FO diameter was 5.1 mm (IQR 0.4). The remaining fetus that required urgent BAS on the second day of life had an IVS with a median FO diameter of 5.4 mm (IQR 0). All 5 fetuses with a restrictive FO appearance and an IVS underwent urgent BAS immediately after birth. In these fetuses, the median FO diameter was 4.1 mm (IQR 0.3).
Non-urgent BAS was performed in 5 neonates (10.4%) beyond 48 hours of life due to postnatal echocardiographic detection of left ventricular outflow tract obstruction (subvalvular pulmonary stenosis). The median time to non-urgent BAS was 15 days (IQR 6). All the fetuses undergoing non-urgent BAS had VSD, with a median FO diameter of 6.3 (IQR 3.2) mm. None underwent arterial switch operation. One neonate underwent Rastelli operation at 11 months, another underwent Nicaidoh operation at 15 months, and another underwent Glenn operation at 24 months. The remaining two newborns were under follow-up.
In total, 43 neonates underwent arterial switch operation, 18 of whom required urgent BAS. The median FO diameter was 5.1 mm (IQR 1.6) in the urgent BAS group as compared with 6.3 mm (IQR 1.3) in fetuses without urgent BAS.