Fetuses with congenital heart disease (CHD) have circulatory changes that may lead to predictable blood flow disturbances that may affect normal brain development. Hypoxemia and hypoperfusion may alter the redox balance leading to oxidative stress (OS), that can be assessed measuring stable end-products. OS biomarkers (OSB) were measured in amniotic fluid in fetuses with (n = 41) and without CHD (n = 44) and analyzed according to aortic flow, expected cyanosis after birth, and a CHD classification derived from this. Birth head circumference (HC) was used as a neurodevelopment biomarker. CHD fetuses had higher levels of ortho-Tyrosine (o-Tyr) than controls (p = 0.0003). There were no differences in o-Tyr levels considering aortic flow obstruction (p = 0.617). Fetuses with expected extreme cyanosis presented the highest levels of o-Tyr (p = 0.003). Among groups of CHD, fetuses without aortic obstruction and extreme cyanosis had the highest levels of o-Tyr (p = 0.005). CHD patients had lower HC than controls (p = 0.023), without correlation with OSB. Patients with HC < 10th percentile, presented high levels of o-Tyr (p = 0.024). Fetuses with CHD showed increased OSB and lower HC when compared to controls, especially those with expected extreme cyanosis. Our results suggest that increased levels of OSB are more influenced by the effect of low oxygenation than by aortic flow obstruction. Future studies with larger sample size are needed to further investigate the role of OSB as an early predictor of neurodevelopmental problems in CHD survivors.

Advances in prenatal diagnosis have improved the perinatal management of congenital heart disease (CHD). However postnatal comorbidities still persist due to multifactorial causes, which limits prenatal prediction of individual outcomes. Oxidative stress (OS), particularly lipid peroxidation, has been suggested to play a role in the development and progression of CHD, with 8-iso-prostaglandin F₂α (8-iso-PGF₂α) serving as a biomarker of oxidative injury. This prospective case–control study aimed to evaluate OS in fetuses with isolated major CHD by comparing amniotic fluid (AF) 8-iso-PGF₂α concentrations with controls. A total of 123 fetuses (83 CHD, 40 controls) were included at a tertiary CHD referral center. CHD cases were subclassified according to anatomical type and expected fetal brain perfusion under placental circulation. Controls were gestational age-matched pregnancies undergoing amniocentesis for indications unlikely to affect OS. All pregnant women underwent standardized fetal biometry, Doppler assessment, and detailed echocardiography. AF samples were obtained by amniocentesis and analyzed for free 8-iso-PGF₂α using a competitive ELISA, with values normalized to creatinine. Clinical, obstetric, and Doppler characteristics were comparable between groups. CHD fetuses showed significantly higher AF 8-iso-PGF₂α concentrations than controls (2849 ± 1377 vs. 2088 ± 1087 ng/mg Cr, p = < 0.001), and remained significant after adjustment for GA, smoking status, diabetes and maternal age and body mass index (BMI). No consistent differences were observed across anatomical or hemodynamic CHD subgroups. These findings provide the first intrauterine evidence of increased lipid peroxidation in fetuses with CHD as reflected by elevated amniotic fluid 8-iso-PGF₂α concentrations.

Introduction: Arhinencephaly have been identified as a significant feature in CHARGE syndrome. This study aimed to evaluate the diagnostic role of olfactory sulci (OS) in identifying CHARGE syndrome among fetuses with major congenital heart defects (CHDs). Methods: We prospectively evaluated OS development in fetuses diagnosed with CHDs from 2017 to 2021. Neurosonography was performed using transabdominal and transvaginal approaches after 30 weeks of gestation. OS assessment was conducted in the trans-frontal coronal plane, classifying their appearance as fully developed, hypoplastic, or absent. Abnormal OS cases underwent MRI and trio-based clinical exome sequencing (CES). Results: The study included 147 fetuses with CHD. Abnormal OS were found in 4 fetuses (2.7%) which also exhibited other additional anomalies. OS were absent in cases 1–3 and hypoplastic in case 4. MRI confirmed OS abnormalities in all cases, and trio-based CES identified a CHD7 gene mutation in cases 1, 2, and 4, supporting the diagnosis of CHARGE syndrome. Case 3 had normal trio-based CES results. No other CHARGE syndrome cases were diagnosed postnatally among the cases with normal OS. Conclusions: Systematic evaluation of OS in fetuses with major CHD might contribute to the diagnosis of CHARGE syndrome. Our findings support the inclusion of OS assessment in the prenatal evaluation of fetuses with major CHDs.