[Sex differences in congenital heart disease]

Risk factors characterisation for CHD: a case-control study in Bogota and Cali, Colombia, 2002-2020

OBJECTIVE

CHDs correspond to 28% of all congenital anomalies, being the leading cause of infant mortality in the first year of life. Thus, it is essential to explore risk factors for CHDs presentation, allowing the detection of probable cases within a population.

METHODS

We identified newborns with CHDs within a cohort from the Program for the Prevention and Monitoring of Congenital Defects in Bogota and Cali, 2002-2020. Cases were classified as isolated, complex isolated, polymalformed, and syndromic. Variables were analysed by comparing case and control averages with Student's t test using a 95% confidence level.

RESULTS

Prevalence obtained was 19.36 per 10 000 live births; non-specified CHD, ventricular septal defect, and atrial septal defect were the most prevalent. As risk factors were found: paternal and maternal age above 45 years, pregestational diabetes, mother's body mass index above 25, low educational level, and socio-economic status. As protective factors: folic acid consumption within the first trimester and pregestational period.

CONCLUSION

Different risk and protective factors associated with the presentation of CHDs have been described. We consider that public health strategies should be aimed to reduce risk factors exposure. Also, improving diagnosis and prognosis by having a close monitoring on high-risk patients.

Association of patent ductus arteriosus with fetal factors and endotypes of prematurity

During fetal life, the ductus arteriosus (DA) acquires the mechanisms for its postnatal closure following a thorough developmental program. This program can be interrupted by preterm birth and is also susceptible to alteration during fetal life by numerous physiological and pathological stimuli. In this review, we aim to summarize the evidence on how physiological and pathological factors affect DA development, eventually leading to patent DA (PDA). Specifically, we reviewed the associations of sex, race, and pathophysiological pathways leading to very preterm birth (endotypes) with PDA incidence and pharmacological closure. Summary of evidence suggests that there are no male-female differences in the incidence of PDA among very preterm infants. In contrast, risk of developing PDA appears to be higher in infants exposed to chorioamnionitis or who are small for gestational age. Finally, hypertensive disorders of pregnancy may be associated with a better response to pharmacological treatment of PDA. All of this evidence comes from observational studies and therefore associations do not imply causation. The current trend for many neonatologists is to wait for the natural evolution of preterm PDA. Continued research is needed to identify which fetal and perinatal factors modulate the eventual late closure of PDA in very and extremely preterm infants.

Early prenatal exposure to air pollutants and congenital heart disease: a nested case-control study

BACKGROUND

Congenital heart disease (CHD) is one of the most common congenital malformations in humans. Inconsistent results emerged in the existed studies on associations between air pollution and congenital heart disease. The purpose of this study was to evaluate the association of gestational exposure to air pollutants with congenital heart disease, and to explore the critical exposure windows for congenital heart disease.

METHODS

The nested case-control study collected birth records and the following health data in Tianjin Women and Children's Health Center, China. All of the cases of congenital heart disease from 2013 to 2015 were selected matching five healthy controls for each case. Inverse distance weighting was used to estimate individual exposure based on daily air pollution data. Furthermore, the conditional logistic regression with distributed lag non-linear model was performed to identify the association between gestational exposure to air pollution and congenital heart disease.

RESULTS

A total of 8,748 mother-infant pairs were entered into the analysis, of which 1,458 infants suffered from congenital heart disease. For each 10 µg/m³ increase of gestational exposure to PM_2.5, the ORs (95% confidence interval, 95%CI) ranged from 1.008 (1.001-1.016) to 1.013 (1.001-1.024) during the 1^st-2^nd gestation weeks. Similar weak but increased risks of congenital heart disease were associated with O₃ exposure during the 1^st week and SO₂ exposure during 6^th-7^th weeks in the first trimester, while no significant findings for other air pollutants.

CONCLUSIONS

This study highlighted that gestational exposure to PM_2.5, O₃, and SO₂ had lag effects on congenital heart disease. Our results support potential benefits for pregnancy women to the mitigation of air pollution exposure in the early stage, especially when a critical exposure time window of air pollutants may precede heart development.

Sex Differences in Patent Ductus Arteriosus Incidence and Response to Pharmacological Treatment in Preterm Infants: A Systematic Review, Meta-Analysis and Meta-Regression

A widely accepted concept in perinatal medicine is that boys are more susceptible than girls to complications of prematurity. However, whether this ‘male disadvantage of prematurity’ also involves persistent patent ductus arteriosus (PDA) has been scarcely investigated. Our aim was to conduct a systematic review and meta-analysis on studies addressing sex differences in the risk of developing PDA among preterm infants. We also investigated whether the response to pharmacological treatment of PDA differs between boys and girls. PubMed/Medline and Embase databases were searched. The random-effects male/female risk ratio (RR) and 95% confidence interval (CI) were calculated. We included 146 studies (357,781 infants). Meta-analysis could not demonstrate sex differences in risk of developing any PDA (37 studies, RR 1.03, 95% CI 0.97 to 1.08), hemodynamically significant PDA (81 studies, RR 1.00, 95% CI 0.97 to 1.02), or in the rate of response to pharmacological treatment (45 studies, RR 1.01, 95% CI 0.98 to 1.04). Subgroup analysis and meta-regression showed that the absence of sex differences was maintained over the years and in different geographic settings. In conclusion, both the incidence of PDA in preterm infants and the response rate to pharmacological treatment of PDA are not different between preterm boys and girls.

Transient increase in VEGF-A leads to cardiac tube anomalies and increased risk of congenital heart malformations

Vascular endothelial growth factor (VEGF) plays a critical role during early heart development. Clinical evidence shows that conditions associated with changes in VEGF signaling in utero are correlated with an increased risk of congenital heart defects (CHD) in newborns. However, how malformations develop after abnormal VEGF exposure is unknown. During embryogenesis, a primitive heart, consisting of an endocardial tube enveloped by a myocardial mantle, is the first organ to function. This tubular heart ultimately transforms into a four-chambered heart. To determine how a transient increase in VEGF prior to heart tube formation affects heart development leading to CHD, we applied exogenous VEGF or a control (vehicle) solution to quail embryos in ovo at Hamburger-Hamilton (HH) stage 8 (28-30 hr of incubation), right before heart tube formation. Light microscopy analysis of embryos re-incubated after treatment for 13 hrs (to approximately HH11/HH12) showed that increased VEGF leads to impaired heart tube elongation accompanied by diameter expansion. Micro-CT analysis of embryos re-incubated for 9 days (to approximately HH38), when the heart is fully formed, showed that VEGF treatment increased the rate of cardiac malformations in surviving embryos. Despite no sex differences in survival, female embryos were more likely to develop cardiac malformations. Our results further suggest that heart tube malformations after a transient increase in VEGF right before heart tube formation may be reversible, leading to normal hearts.

[Demographic analysis of a congenital heart disease clinic of the Mexican Institute of Social Security, with special interest in the adult]

INTRODUCTION

Congenital heart disease (CHD) has an incidence of 8-10 cases per 1000 live births. In Mexico, there are 18,000-20,000 new cases per year. Most tertiary care centers for CHD attend only pediatric population; the Mexican Institute of Social Security (IMSS) has a clinic that attends pediatric and adult population.

OBJECTIVE

To analyze the demographic aspects of the CHD clinic of IMSS.

METHODS

From 2011 to 2016 a cross-sectional study of the CC clinic of a third level hospital of the IMSS, including all patients with confirmed structural heart disease of recent diagnosis was carried out. The sex, age, reference entity, antecedent of pregnancy and treatment were registered. The population was divided into age ranges (<2 years, 2.1-6 years, 6.1-10 years, 10.1-17 years and >17.1 years). Descriptive statistics and χ² test were used in qualitative variables.

RESULTS

3,483 patients with CHD (male:female ratio, 0.8:1.2) were included. Increased pulmonary flow acyanogenic cardiopathies were the most frequent CHD group (47.2%), with atrial septal defect being the most frequent diagnosis overall; 25.6% were adults and 35% of women with a history of pregnancy. Chiapas was Federal entity with greater proportion of patients diagnosed in the adult stage (33.82%); 7% were not candidates for any treatment for complications of the disease.

CONCLUSIONS

CHD is a late diagnosis; it is necessary to create a national register to promote new health policies and a rational distribution of resources for these patients.