Impact of extracardiac pathology on head growth in fetuses with congenital heart defect

Placenta histology related to flow and oxygenation in fetal congenital heart disease

BACKGROUND

Fetuses with congenital heart defects (CHD) show delayed neurodevelopment, fetal growth restriction (FGR) and placenta related complications. The neurodevelopmental delay may be, partly, attributed to placental factors.

AIM

As both placental development and fetal aortic flow/oxygenation influence neurodevelopment, placentas were compared within fetal CHD groups based on aortic oxygenation and flow, aiming to unravel the true effects in the developmental processes.

STUDY DESIGN

Placental tissues of pregnancies with fetal CHD and healthy controls were selected from biobanks of two Dutch academic hospitals (LUMC, UMCU). Additionally, biometry and Dopplers were assessed.

SUBJECTS

CHD cases with reduced oxygenation (RO) towards the fetal brain were compared to cases with reduced flow (RF) in the aortic arch and healthy controls. Genetic abnormalities, termination of pregnancy, fetal demise and/or multiple pregnancies were excluded.

OUTCOME MEASURES

Histological outcomes were related to fetal Dopplers and biometry. A placenta severity score was used to assess the severity of placental abnormalities per case.

RESULTS

In CHD, significantly more delayed maturation, maternal vascular malperfusion, fetal hypoxia and higher placenta severity scores (median 14 in RO, 14 in RF, 5 in controls, p < 0.001) were observed. Doppler abnormalities (PI UA > p90, PI MCA < p10, CPR < p10) and FGR were more often found in CHD. There were no differences in placental abnormalities, fetal growth and fetal Dopplers between cases with RO and RF.

CONCLUSION

Fetal hemodynamics in the ascending aorta could not be related to placenta characteristics. We hypothesize that placental development influences neurodevelopment in excess of hemodynamics in CHD cases.

Birthweight of children with isolated congenital heart disease-A sibling analysis study

OBJECTIVE

Congenital heart disease (CHD) is associated with decreased birthweight (BW) compared to population-based references. The aim of this study was to compare the BW of isolated CHD cases to their siblings, thus controlling for unknown and unmeasured confounders within the family.

METHODS

All isolated CHD cases in the Leiden University Medical Center were included (2002-2019). Generalized estimated equation models were constructed to compare BW z scores of CHD neonates with their siblings. Cases were clustered to minor or severe CHD and stratified according to the aortic flow and oxygenation to the brain.

RESULTS

The overall BW z score of siblings was 0.032 (n = 471). The BW z score was significantly lower in CHD cases (n = 291) compared to their siblings (-0.20, p = 0.005). The results were consistent in the subgroup analysis of severe and minor CHD (BW z score difference -0.20 and -0.10), but did not differ significantly (p = 0.63). Stratified analysis regarding flow and oxygenation showed no BW difference between the groups (p = 0.1).

CONCLUSION

Isolated CHD cases display a significantly lower BW z score compared to their siblings. As the siblings of these CHD cases show a BW distribution similar to the general population, this suggests that shared environmental and maternal influences between siblings do not explain the difference in BW.

Optimizing Neurodevelopmental Outcomes in Neonates With Congenital Heart Disease

Neurodevelopmental impairment is a common and important long-term morbidity among infants with congenital heart disease (CHD). More than half of those with complex CHD will demonstrate some form of neurodevelopmental, neurocognitive, and/or psychosocial dysfunction requiring specialized care and impacting long-term quality of life. Preventing brain injury and treating long-term neurologic sequelae in this high-risk clinical population is imperative for improving neurodevelopmental and psychosocial outcomes. Thus, cardiac neurodevelopmental care is now at the forefront of clinical and research efforts. Initial research primarily focused on neurocritical care and operative strategies to mitigate brain injury. As the field has evolved, investigations have shifted to understanding the prenatal, genetic, and environmental contributions to impaired neurodevelopment. This article summarizes the recent literature detailing the brain abnormalities affecting neurodevelopment in children with CHD, the impact of genetics on neurodevelopmental outcomes, and the best practices for neonatal neurocritical care, focusing on developmental care and parental support as new areas of importance. A framework is also provided for the infrastructure and resources needed to support CHD families across the continuum of care settings.

Association of Cerebrovascular Stability Index and Head Circumference Between Infants With and Without Congenital Heart Disease

Congenital heart disease (CHD) is a common birth defect in the United States. CHD infants are more likely to have smaller head circumference and neurodevelopmental delays; however, the cause is unknown. Altered cerebrovascular hemodynamics may contribute to neurologic abnormalities, such as smaller head circumference, thus we created a novel Cerebrovascular Stability Index (CSI), as a surrogate for cerebral autoregulation. We hypothesized that CHD infants would have an association between CSI and head circumference. We performed a prospective, longitudinal study in CHD infants and healthy controls. We measured CSI and head circumference at 4 time points (newborn, 3, 6, 9 months). We calculated CSI by subtracting the average 2-min sitting from supine cerebral oxygenation (rcSO₂) over three consecutive tilts (0-90°), then averaged the change score for each age. Linear regressions quantified the relationship between CSI and head circumference. We performed 177 assessments in total (80 healthy controls, 97 CHD infants). The average head circumference was smaller in CHD infants (39.2 cm) compared to healthy controls (41.6 cm) (p < 0.001) and head circumference increased by 0.27 cm as CSI improved in the sample (p = 0.04) overall when combining all time points. Similarly, head circumference increased by 0.32 cm as CSI improved among CHD infants (p = 0.04). We found CSI significantly associated with head circumference in our sample overall and CHD infants alone, which suggests that impaired CSI may affect brain size in CHD infants. Future studies are needed to better understand the mechanism of interaction between CSI and brain growth.

The Effect of Size and Asymmetry at Birth on Brain Injury and Neurodevelopmental Outcomes in Congenital Heart Disease

Poor and asymmetric fetal growth have been associated with neonatal brain injury (BI) and worse neurodevelopmental outcomes (NDO) in the growth-restricted population due to placental insufficiency. We tested the hypothesis that postnatal markers of fetal growth (birthweight (BW), head circumference (HC), and head to body symmetry) are associated with preoperative white matter injury (WMI) and NDO in infants with single ventricle physiology (SVP) and d-transposition of great arteries (TGA). 173 term newborns (106 TGA; 67 SVP) at two sites had pre-operative brain MRI to assess for WMI and measures of microstructural brain development. NDO was assessed at 30 months with the Bayley Scale of Infant Development-II (n = 69). We tested the association between growth parameters at birth with the primary outcome of WMI on the pre-operative brain MRI. Secondary outcomes included measures of NDO. Newborns with TGA were more likely to have growth asymmetry with smaller heads relative to weight while SVP newborns were symmetrically small. There was no association between BW, HC or asymmetry and WMI on preoperative brain MRI or with measures of microstructural brain development. Similarly, growth parameters at birth were not associated with NDO at 30 months. In a multivariable model only cardiac lesion and site were associated with NDO. Unlike other high-risk infant populations, postnatal markers of fetal growth including head to body asymmetry that is common in TGA is not associated with brain injury or NDO. Lesion type appears to play a more important role in NDO in CHD.

Birthweight and isolated congenital heart defects - A systematic review and meta-analysis

Background

Birthweight (BW) is an important prognostic factor in newborns with congenital heart defects (CHD).

Objectives

To give an overview of the literature on BW z‐score in children with isolated CHD.

Search strategy

A systematic search was performed on isolated CHD and BW in PubMed, Embase, Web of Science, COCHRANE Library and Emcare.

Selection criteria

Neonates with isolated CHD were included if a BW percentile, BW z‐score or % small‐or‐gestational age (SGA) was reported.

Data collection and analysis

BW z‐score and percentage SGA were pooled with random‐effect meta‐analysis. Quality and risk of bias were assessed using the modified Newcastle Ottawa Scale.

Main results

Twenty‐three articles (27 893 cases) were included. BW z‐scores were retrieved from 11 articles, resulting in a pooled z‐score of −0.20 (95% CI −0.50 to 0.11). The overall pooled prevalence of SGA <10th percentile was 16.0% (95% CI 11.4–20.5; 14 studies). Subgroup analysis of major CHD showed similar results (BW z‐score −0.23 and percentage SGA 16.2%).

Conclusions

Overall BW in isolated CHD is within range of normality but impaired, with a 1.6‐fold higher risk of SGA, irrespective of the type of CHD (major CHD vs all CHD combined). Our findings underline the association between CHD and BW. The use of BW z‐scores provides insight into growth of all fetuses with CHD.

Tweetable abstract

Infants with a congenital heart defect (CHD) have a lower birthweight z‐score and a higher incidence of small‐for‐gestational age (<10th percentile). This was encountered both in the major CHD‐group as well as in all‐CHD combined group analysis. Future research on the association between birthweight and CHD should include all types of CHDs (including mild cardiac defects) and placental‐related disease, such as pre‐eclampsia. We advocate the use of international standardised fetal growth and birthweight charts in CHD research.

Infants with a congenital heart defect (CHD) have a lower birthweight z‐score and a higher incidence of small‐for‐gestational age (<10th percentile). This was encountered both in the major CHD‐group as well as in all‐CHD combined group analysis. Future research on the association between birthweight and CHD should include all types of CHDs (including mild cardiac defects) and placental‐related disease, such as pre‐eclampsia. We advocate the use of international standardised fetal growth and birthweight charts in CHD research.

Abnormal Extracardiac Development in Fetuses With Congenital Heart Disease

BACKGROUND

Knowledge about extracardiac anomalies (ECA) in fetal congenital heart disease (CHD) can improve our understanding of the developmental origins of various outcomes in these infants. The prevalence and spectrum of ECA, including structural brain anomalies (SBA), on magnetic resonance imaging (MRI) in fetuses with different types of CHD and at different gestational ages, is unknown.

OBJECTIVES

The purpose of this study was to evaluate ECA rates and types on MRI in fetuses with different types of CHD and across gestation.

METHODS

A total of 429 consecutive fetuses with CHD and MRI between 17 and 38 gestational weeks were evaluated. ECA and SBA rates were assessed for each type of CHD and classified by gestational age (<25 or ≥25 weeks) at MRI.

RESULTS

Of all 429 fetuses with CHD, 243 (56.6%) had ECA on MRI, and 109 (25.4%) had SBA. Among the 191 fetuses with normal genetic testing results, the ECA rate was 54.5% and the SBA rate 19.4%. Besides SBA, extrafetal (21.2%) and urogenital anomalies (10.7%) were the most prevalent ECA on MRI in all types of CHD. Predominant SBA were anomalies of hindbrain-midbrain (11.0% of all CHD), dorsal prosencephalon (10.0%) development, and abnormal cerebrospinal fluid spaces (10.5%). There was no difference in the prevalence or pattern of ECA between early (<25 weeks; 45.7%) and late (≥25 weeks; 54.3%) fetal MRI.

CONCLUSIONS

ECA and SBA rates on fetal MRI are high across all types of CHD studied, and ECA as well as SBA are already present from midgestation onward.

Reference biometry of foetal brain by prenatal MRI and the distribution of measurements in foetuses with ventricular septal defect

OBJECTIVE

To provide the reference biometric measurements of the normal foetal brain by prenatal MRI and describe the distribution of measurements in the foetuses with ventricular septal defect (VSD).

METHODS

This retrospective study analysed the biometric measurements of 218 foetuses between 18 - 37 gestational weeks with normal MRI findings from July 2014 to August 2019, as well as 18 foetuses with VSD. The measurements included fronto-occipital diameter (FOD), biparietal diameter (BPD), and transverse cerebellar diameter (TCD). All the prenatal MRI examinations have been taken on the same 1.5 T MR unit with a standard protocol of the foetal brain. All the linear measurements of the foetal brain were obtained on the T2-weighted imaging. The distribution of measurements in 18 foetuses with VSD was plotted on centile curves.

RESULTS

The reference data were presented in mean, standard deviation, 95% predicted confidence intervals, and the 3rd, 10th, 25th, 50th, 75th, 90th, 97th centiles at each gestational age. The value of TCD in 56% (10/18 cases) foetuses with VSD was lower than the 3rd centile, and the rate for FOD and BPD was 33% (6/18 cases) and 22% (4/18 cases) separately. On the curves, most VSD cases with measurements lower than the 3rd centile were in relatively early gestational stage (≤28 weeks).

CONCLUSIONS

We have presented reference linear biometry of the foetal brain by prenatal MRI from 18 to 37 gestational weeks, which could help us to interpret and monitor the brain development for foetuses with VSD and other congenital heart diseases.Key messages:We have presented reference linear biometry of the foetal brain by prenatal MRI from 18 to 37 gestational weeks in multiple statistical methods: mean and standard deviation; 95% predicted confidence intervals and the 3rd, 10th, 25th, 50th, 75th, 90th, 97th centiles.Our data showed that the involvement of the brain in VSD may be not globally, but regionally, and the cerebellum may be more possible to be involved.We speculated that the earlier the VSD diagnosed the worse the brain involved, which might suggest a poor outcome and necessary follow-up.

Placenta morphology and biomarkers in pregnancies with congenital heart disease - A systematic review

Impaired placentation is an important contributing factor to intra-uterine growth restriction and pre-eclampsia in fetuses with congenital heart defects (CHD). These pregnancy complications occur more frequently in pregnancies with fetal CHD. One of the most important factors influencing the life of children with CHD is neurodevelopmental delay, which seems to start already in utero. Delayed neurodevelopment in utero may be correlated or even (partly) explained by impaired placentation in CHD cases. This systematic review provides an overview of published literature on placental development in pregnancies with fetal CHD. A systematic search was performed and the Newcastle-Ottawa scale was used to access data quality. Primary outcomes were placenta size and weight, vascular and villous architecture, immunohistochemistry, angiogenic biomarkers and/or placental gene expression. A total of 1161 articles were reviewed and 21 studies were included. Studies including CHD with a genetic disorder or syndrome and/or multiple pregnancies were excluded. Lower placental weight and elevated rates of abnormal umbilical cord insertions were found in CHD. Cases with CHD more frequently showed microscopic placental abnormalities (i.e. abnormal villous maturation and increased maternal vascular malperfusion lesions), reduced levels of angiogenic biomarkers and increased levels of anti-angiogenic biomarkers in maternal serum and umbilical cord blood. Altered gene expression involved in placental development and fetal growth were found in maternal serum and CHD placentas. In conclusion, abnormal placentation is found in CHD. More extensive studies are needed to elucidate the contribution of impaired placentation to delayed neurodevelopment in CHD cases.

Cerebrovascular blood flow in patients with tetralogy of fallot: prediction for early surgical intervention

OBJECTIVES

Children with tetralogy of Fallot (TOF) require initial intervention at varying times reflecting a spectrum of obstruction to pulmonary blood flow. In utero, fetal patients with right sided obstructive lesions demonstrate increased middle cerebral artery (MCA) pulsatility index (PI). We sought to determine whether MCA flow patterns are associated with the degree of pulmonary obstruction and the consequential need for early surgical intervention (ESI).

METHODS

We performed a multi-center retrospective study evaluating patients with a prenatal diagnosis of TOF. All echocardiographic fetal studies performed from 16 weeks' gestational age through delivery were reviewed between 2001 and 2015 with subsequent postnatal medical chart review.

RESULTS

82 patients met inclusion criteria. Patients who ultimately required ESI (n=30) demonstrated an increased MCA PI z-score (-0.68 vs -1.32, p=0.02) compared to those who did not (n=52). An elevated MCA PI in patients with TOF was associated with ESI after 24 weeks' gestational age (-0.36 vs -1.22, p=0.02).

CONCLUSIONS

Fetal patients with TOF demonstrate altered MCA flow that correlates with need for ESI. This effect is blunted earlier in gestation which may reflect cerebral autoregulation. MCA PI may be a beneficial tool in helping determine perinatal management and counseling for patients with TOF.