Are There Head Volume Alterations at 11 to 14 Weeks in Fetuses with Congenital Heart Defects? A First Trimester Case Series

Placental vascular malperfusion lesions in fetal congenital heart disease

BACKGROUND

Fetuses with congenital heart disease are at increased risk of perinatal morbidity and mortality, which is highly influenced by their prenatal health. Placental function is vital for the health of the fetus, but increased rates of pathologic lesions of the placenta have been observed in pregnancies complicated by fetal congenital heart disease.

OBJECTIVE

This study aimed to determine the prevalence of both gross and histologic placental pathologies in a cohort of pregnancies complicated by fetal congenital heart disease vs healthy controls using the Amsterdam Placental Workshop Group Consensus Statement sampling and definitions of placental lesions.

STUDY DESIGN

This single-center retrospective cohort study included placental examinations from pregnancies diagnosed prenatally with fetal congenital heart disease between 2010 and 2019; moreover, control placentas were collected from pregnancies without maternal or fetal complications. Placentas were sampled and evaluated according to the Amsterdam Placental Workshop Group Consensus Statement and gross and histopathologic diagnoses determined.

RESULTS

Approximately 80% of fetuses diagnosed with congenital heart disease (n=305) had a placental examination for comparison with controls (n=40). Of note, 239 placentas (78%) in the group with fetal congenital heart disease had at least 1 gross or histopathologic lesion compared with 11 placentas (28%) in the control group (P<.01). One-third of placentas complicated by fetal congenital heart disease met the criteria for small for gestational age, and 48% of placentas had one or more chronic lesions, including maternal vascular malperfusion (23% vs 0%; P<.01), villitis of unknown etiology (22% vs 0%; P<.01), fetal vascular malperfusion (20% vs 0%; P<.01), and other chronic lesions (16% vs 0%; P<.01). Acute inflammation was equally present in both the group with fetal congenital heart disease and the control group (28% vs 28%; P=1.00). Although gestational age and birthweight z score were similar between the 2 groups, birth head circumference was 1.5 cm less in pregnancies complicated by fetal congenital heart disease with a significantly lower z score compared with the control group (-0.52±1.22 vs 0.06±0.69; P<.01).

CONCLUSION

Vascular malperfusion lesions and chronic forms of inflammation occur at markedly higher rates in placentas complicated by fetal congenital heart disease, which may contribute to the decreased head circumference at birth. Further work in neuroplacentology is needed to explore connections among cardiac defects, placental vascular malperfusion lesions, and fetal brain development.

Fetal brain issues in congenital heart disease

Following the improvements in the clinical management of patients with congenital heart disease (CHD) and their increased survival, neurodevelopmental outcome has become an emerging priority in pediatric cardiology. Large-scale efforts have been made to protect the brain during the postnatal, surgical, and postoperative period; however, the presence of brain immaturity and injury at birth suggests in utero and peripartum disturbances. Over the past decade, there has been considerable interest and investigations on fetal brain growth in the setting of CHD. Advancements in fetal brain imaging have identified abnormal brain development in fetuses with CHD from the macrostructural (brain volumes and cortical folding) down to the microstructural (biochemistry and water diffusivity) scale, with more severe forms of CHD showing worse disturbances and brain abnormalities starting as early as the first trimester. Anomalies in common genetic developmental pathways and diminished cerebral substrate delivery secondary to altered cardiovascular physiology are the forefront hypotheses, but other factors such as impaired placental function and maternal psychological stress have surfaced as important contributors to fetal brain immaturity in CHD. The characterization and timing of fetal brain disturbances and their associated mechanisms are important steps for determining preventative prenatal interventions, which may provide a stronger foundation for the developing brain during childhood.

Brain angiogenic gene expression in fetuses with congenital heart disease

OBJECTIVE

To assess potential differences in the expression of antiangiogenic and angiogenic factors and of genes associated with chronic hypoxia in cerebral tissue of euploid fetuses with congenital heart disease (CHD) vs those without.

METHODS

Cerebral tissue was obtained from 15 fetuses with CHD and 12 control fetuses that had undergone termination of pregnancy. Expression profiles of the antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1), the angiogenic vascular endothelial growth factor-A (VEGF-A) and placental growth factor (PlGF), and of genes associated with chronic hypoxia were determined by real-time polymerase chain reaction in tissue from the frontal cortex and the basal ganglia of the fetuses.

RESULTS

Expression of sFlt-1 was 48% higher in the frontal cortex (P = 0.0431) and 72% higher in the basal ganglia (P = 0.0369) of CHD fetuses compared with controls. The expression of VEGF-A was 60% higher (P = 0.0432) and that of hypoxia-inducible factor 2-alpha was 98% higher (P = 0.0456) in the basal ganglia of CHD fetuses compared with controls. No significant differences were observed between the two groups in the expression of PlGF and hypoxia-inducible factor 1-alpha.

CONCLUSION

An overall dysregulation of angiogenesis with a net balance towards an antiangiogenic environment was observed in the cerebral tissue of fetuses with CHD, suggesting that these fetuses may have an intrinsic angiogenic impairment that could contribute to impaired brain perfusion and abnormal neurological development later in life. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.