Maternal Predictors of Disparate Outcomes in Children With Single Ventricle Congenital Heart Disease

Hypoplastic Left Heart Syndrome: A Review

Hypoplastic left heart syndrome is a rare and poorly understood congenital disorder featuring a univentricular myocardium, invariably resulting in early childhood death if left untreated. The process to palliate this congenital cardiomyopathy is of high complexity and may include invasive interventions in the first week of life. The preferred treatment strategy involves a staged correction with 3 surgical procedures at different points in time. The Norwood procedure is usually performed within the first weeks of life and aims to increase systemic circulation and relieve pulmonary vascular pressure. This procedure is followed by the bidirectional Glenn and the Fontan procedures in later life, which offer to decrease stress in the ventricular chamber. The prognosis of children with this disease has greatly improved in the past decades; however, it is still largely driven by multiple modifiable and nonmodifiable variables. Novel and clever alternatives have been proposed to improve the survival and neurodevelopment of these patients, although they are not used as standard of care in all centers. The neurodevelopmental outcomes among these patients have received particular attention in the last decade in light to improve this very limiting associated comorbidity that compromises quality of life.

Association of Maternal and Neonatal Birth Outcomes With Subsequent Pediatric Transplants

BACKGROUND

We identified maternal and neonatal birth characteristics that were associated with organ or tissue transplants during childhood.

METHODS

We designed a retrospective cohort study of the population of children born between 2006 and 2019 in Quebec, Canada. The exposure included birth complications such as congenital anomaly, neonatal blood transfusion, and oligohydramnios. The main outcome measure was organ or tissue transplantation before 14 y of age. We categorized transplants according to type (major organs versus superficial tissues). To determine the association of birth characteristics with risk of pediatric transplant, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards models adjusted for potential confounders.

RESULTS

The cohort comprised 1 038 375 children with 7 712 678 person-years of follow-up, including 436 children who had transplants before 14 y of age. Birth complications were predominantly associated with major organ transplants. Congenital anomaly was associated with heart or lung (HR, 10.41; 95% CI, 5.33-20.33) and kidney transplants (HR, 13.69; 95% CI, 7.48-25.06), compared with no anomaly. Neonatal blood transfusion was associated with all major organ transplants, compared with no transfusion. Maternal complications were not as strongly associated with the risk of childhood transplant, although oligohydramnios was associated with 16.84 times (95% CI, 8.09-35.02) the risk of kidney transplant, compared with no oligohydramnios.

CONCLUSIONS

Adverse birth outcomes such as congenital anomaly, neonatal blood transfusion, and maternal oligohydramnios are associated with a greater risk of transplantation before 14 y of age. Maternal and neonatal birth outcomes may be useful predictors of transplantation.

Association of Gestational Weight Gain With Infant Morbidity and Mortality in the United States

IMPORTANCE

The associations of gestational weight gain (GWG) with infant morbidity and mortality are unclear, and the existing recommendations for GWG have not been stratified by the severity of obesity.

OBJECTIVES

To identify optimal GWG ranges associated with reduced risks of infant morbidity and mortality across maternal body mass index (BMI) categories.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used US nationwide, linked birth and infant death data between 2011 and 2015 to assess the associations of GWG in 2.0-kg groups with infant morbidity and mortality and identified optimal GWG ranges associated with reduced risks of both outcomes, using multivariable logistic regression models. Statistical analysis was performed from February 11 to October 14, 2021.

EXPOSURE

Gestational weight gain equivalent to 40 weeks.

MAIN OUTCOMES AND MEASURES

The 2 main outcomes were (1) significant morbidity of the newborn infant, defined as any presence of assisted ventilation, admission to the neonatal intensive care unit, surfactant therapy, antibiotic therapy, or seizures; and (2) infant mortality younger than 1 year of age (<1 hour, 1-23 hours, 1-6 days, 7-27 days, or 28-365 days after birth).

RESULTS

In this study of 15 759 945 mother-infant dyads, the mean (SD) age of the women was 28.1 (5.9) years. Women gained a mean (SD) of 14.1 (7.3) kg during pregnancy, and the mean (SD) GWG decreased with BMI categories (underweight, 15.7 [6.4] kg; normal weight, 15.4 [6.2] kg; overweight, 14.2 [7.4] kg; obesity class 1, 12.2 [8.0] kg; obesity class 2, 10.3 [8.4] kg; obesity class 3, 8.2 [9.2] kg; P < .001). A total of 8.8% of the newborns experienced significant morbidity, with the lowest prevalence among infants delivered by women in the normal weight BMI class (8.0%) and the highest among infants delivered by women with class 3 obesity (12.4%); 0.34% of infants died within 1 year of birth, with the lowest prevalence among infants delivered by women in the normal weight BMI class (0.28%) and the highest among infants delivered by women with class 3 obesity (0.58%). Optimal GWG ranges were 12.0 to less than 24.0 kg for underweight and normal weight women, 10.0 to less than 20.0 kg for overweight women, 8.0 to less than 16.0 kg for women with class 1 obesity, 6.0 to less than 16.0 kg for class 2 obesity, and 6.0 to less than 10.0 kg for class 3 obesity. The lower bounds of the optimal GWG ranges appeared to be higher than the existing recommendations for overweight women (10.0 vs 7.0 kg) and for those with class 1 (8.0 vs 5.0 kg), class 2 (6.0 vs 5.0 kg), and class 3 (6.0 vs 5.0 kg) obesity.

CONCLUSIONS AND RELEVANCE

This study analyzed the associations of GWG with infant morbidity and mortality across BMI categories and found that inadequate GWG was associated with increased risks of adverse infant outcomes even for women with obesity. The results suggested that weight maintenance or weight loss should not be used as routine guidelines.

Maternal obesity persistently alters cardiac progenitor gene expression and programs adult-onset heart disease susceptibility

Objective

Heart disease risk can be programmed by intrauterine exposure to obesity. Dysregulating key transcription factors in cardiac progenitors can cause subsequent adult-onset heart disease. In this study, we investigated the transcriptional pathways that are altered in the embryonic heart and linked to heart disease risk in offspring exposed to obesity during pregnancy.

Methods

Female mice were fed an obesogenic diet and mated with males fed a control diet. Heart function and genome-wide gene expression were analyzed in adult offspring born to obese and lean mice at baseline and in response to stress. Cross-referencing with genes dysregulated genome-wide in cardiac progenitors from embryos of obese mice and human fetal hearts revealed the transcriptional events associated with adult-onset heart disease susceptibility.

Results

We found that adult mice born to obese mothers develop mild heart dysfunction consistent with early stages of disease. Accordingly, hearts of these mice dysregulated genes controlling extracellular matrix remodeling, metabolism, and TGF-β signaling, known to control heart disease progression. These pathways were already dysregulated in cardiac progenitors in embryos of obese mice. Moreover, in response to cardiovascular stress, the heart of adults born to obese dams developed exacerbated myocardial remodeling and excessively activated regulators of cell-extracellular matrix interactions but failed to activate metabolic regulators. Expression of developmentally regulated genes was altered in cardiac progenitors of embryos of obese mice and human hearts of fetuses of obese donors. Accordingly, the levels of Nkx2-5, a key regulator of heart development, inversely correlated with maternal body weight in mice. Furthermore, Nkx2-5 target genes were dysregulated in cardiac progenitors and persistently in adult hearts born to obese mice and human hearts from pregnancies affected by obesity.

Conclusions

Obesity during pregnancy alters Nkx2-5-controlled transcription in differentiating cardiac progenitors and persistently in the adult heart, making the adult heart vulnerable to dysregulated stress responses.

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Maternal obesity programs progressive heart dysfunction in adult offspring.

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Offspring of obese dams are prone to dysregulated stress responses in the heart.

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Nkx2-5-controlled transcription is dysregulated in hearts exposed to obesity in utero.

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Obesity during pregnancy broadly affects gene expression in the embryonic heart.

Maternal Predictors of Disparate Outcomes in Children With Single Ventricle Congenital Heart Disease

Background

Significant variability in morbidity and mortality persists for children with functionally single ventricle congenital heart disease (SV‐CHD) despite standardization in medical and surgical care. We hypothesized that maternal health factors may be associated with an increased risk of poor outcomes in children with SV‐CHD.

Methods and Results

This retrospective, observational, cohort study included term maternal‐infant pairs with a diagnosis of SV‐CHD who underwent surgical palliation from 2006 to 2015 at Primary Children's Hospital. Pairs lacking maternal variables of interest or infant follow‐up data were excluded. The association of maternal risk factors of abnormal pre‐pregnancy body mass index, abnormal gestational weight gain (<7 or >20 kg), hypertensive disorders, and gestational diabetes mellitus with death/transplant and hemodynamics were analyzed using regression models. Of 190 infants, 135 (71%) maternal‐infant dyads had complete data for inclusion. Death or transplant occurred in 48 infants (36%) during an average follow‐up of 2.2 years (0.1–11.7 years). Abnormal gestational weight gain was associated with an increased risk of death and/or transplant in logistic regression (odds ratio, 3.22; 95% CI, 1.32–7.86; P=0.01), but not Cox regression (hazard ratio, 1.9; 95% CI, 1.0–3.7; P=0.055). Mean pulmonary artery pressures were higher in the setting of abnormal gestational weight gain (16.5±2.9 versus 14.7±3.0 mm Hg; P<0.001), and abnormal pre‐pregnancy body mass index (15.7±3.5 versus 14.2±2.1 mm Hg; P<0.001) in the systemic right ventricle group.

Conclusions

Abnormal gestational weight gain (excessive or inadequate) is a novel risk factor for worse outcomes in SV‐CHD. The fetoplacental environment may alter the trajectory of vascular development to impact outcomes in infants with SV‐CHD.