Analysis of the Seasonal Trend of Congenital Heart Defects

The effect of China's birth policy changes on birth defects-A large hospital-based cross-sectional study

A retrospective analysis of birth data hospital-based obtained from 14 monitoring areas in the Huaihe River Basin from 2009 to 2019 was conducted. Trend in the total prevalence of birth defects (BDs) and subgroups were analyzed using the Joinpoint Regression model. The incidence of BDs increased gradually from 118.87 per 10,000 in 2009 to 241.18 per 10,000 in 2019 (AAPC = 5.91, P < 0.001). Congenital heart diseases were the most common subtype of BDs. The proportion of maternal age younger than 25 decreased but the age 25-40 years increased significantly (AAPC<20=-5.58; AAPC20-24=-6.38; AAPC25-29 = 5.15; AAPC30-35 = 7.07; AAPC35-40 = 8.27; All P < 0.05). Compared with the one-child policy period, the risk of BDs was greater for groups among maternal age younger than 40 years during the partial and universal two-child policy period (P < 0.001). The incidence of BDs and the proportion of women with advanced maternal age in Huaihe River Basin is increasing. There was an interaction between changes in birth policy and the mother's age on the risk of BDs.

Maternal air pollution exposure and neonatal congenital heart disease: A multi-city cross-sectional study in eastern China

OBJECTIVE

To examine the association between air pollution and neonatal congenital heart disease (CHD), and evaluate the cumulative burden of CHD attributed to above certain level for ambient air pollution exposure.

METHODS

We identified newborns who were diagnosed as CHD by echocardiography in Network Platform for Congenital Heart Disease (NPCHD) from January 2019 to December 2020 in 11 cities eastern China. The exposure lag response relationship between air pollutants (PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃) concentration and CHDs was calculated by the distributed lag nonlinear model (DLNM). We further calculated the cumulative risk ratios (CRRs) of each air pollutant above reference concentrations on CHDs.

RESULTS

A total of 5904 CHDs from 983, 523 newborns were enrolled in this study. A 10 μg/m³ increase in PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃ exposure was associated with an increased risk of higher CHD incident RR = 1.025, 95% CI: 1.016-1.038 for PM_2.5 in the third trimester, RR = 1.001, 95% CI: 1.000-1.002 for PM₁₀ in the third trimester, 1.020, 95%CI: 1.004-1.036 for NO₂ in the third trimester, RR = 1.001, 95%CI: 1.000-1.002 for O₃ in the first trimester, all P value < 0.05). Cumulative effect curves of PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ were observed as sub-linear with a maximum of 1.876 (95%CI:1.220-2.886), 1.973 (95%CI:1.477,2.637), 2.169 (95%CI:1.347-3.493), 2.902 (95%CI:1.859-4.530), 1.398 (95%CI:1.080-1.809), 2.691 (95%CI:1.705-4.248), respectively. Significant associations were observed for air pollutants and CHDs in cities with higher average education years and babies concepted in cold season.

CONCLUSIONS

Our findings could provide growing evidence regarding the adverse health effects of air pollution on CHD, thereby strengthening the hypothesis that air pollutants have harmful impacts on cardiac development. Further studies are needed to verify the associations.

Novel insertion mutation (Arg1822_Glu1823dup) in MYH6 coiled-coil domain causing familial atrial septal defect

OBJECTIVE

Atrial septal defect, secundum (ASD Ⅱ, OMIM: 603642) is the second common congenital heart defect (CHD) in China. However, the genetic etiology of familial ASD II remains elusive.

METHODS AND RESULTS

Using whole-exome sequencing (WES) and Sanger sequencing, we identified a novel myosin heavy chain 6 (MYH6) gene insertion variation, NM_002471.3: c.5465_5470dup (Arg1822_Glu1823dup), in a large Chinese Han family with ASD II. The variant Arg1822_Glu1823dup co-segregated with the disease in this family with autosomal dominant inheritance. The insertion variant located in the coiled-coil domain of the MYH6 protein, which is highly conserved across homologous myosin proteins and species. In transfected myoblast C2C12 cell lines, the MYH6 Arg1822_Glu1823dup variant significantly impaired myofibril formation and increased apoptosis but did not significantly reduce cell viability. Furthermore, molecular simulations revealed that the Arg1822_Glu1823dup variant impaired the myosin α-helix, increasing the stability of the coiled-coil myosin dimer, suggesting that this variant has an effect on the coiled-coil domain self-aggregation. These findings indicate that Arg1822_Glu1823dup variant plays a crucial role in the pathogenesis of ASD II.

CONCLUSION

Our findings expand the spectrum of MYH6 variations associated with familial ASD II and may provide a molecular basis in genetic counseling and prenatal diagnosis for this Chinses family.

Seasonality of Hypoplastic Left Heart Syndrome and Single Ventricle Heart in Poland in the Context of Air Pollution

Hypoplastic left heart syndrome (HLHS) and single ventricle (SV) remain a significant cause of cardiac deaths occurring in the first week of life. Their pathogenesis and seasonal frequency are still unknown. Therefore, we attempt to look at the genesis of the HLHS and SV in the context of territorial distribution as well as seasonality. A total of 193 fetuses diagnosed with HLHS and 92 with SV were selected. The frequency was analyzed depending on the year, calendar month, quarter and season (fall-winter vs. spring-summer). The spatial distribution of HLHS and SV in Poland was analyzed. We observed a statistically significant overrepresentation of HLHS formation frequency in March: 27 (14.00%) in comparison to a monthly median of 15 (IQR: 13.75-16.25; p = 0.039), as well as a significantly higher frequency of HLHS in 2007-2009: 65 cases (33.68%) in comparison to the annual mean of 13.79 ± 6.36 (p < 0.001). We noted a higher frequency of SV among parous with the last menstrual period reported in the fall/winter season of 58 vs. 34 in the spring/summer season (p = 0.014). The performed analysis also revealed significant SV overrepresentation in 2008: 11 cases (12.00%) in comparison to the annual mean of 6.57 ± 2.71 (p = 0.016). Every single case of HLHS was observed when the concentration of benzo(a)pyrene and/or PM10 exceeded the acceptable/target level. Our research indicates that both the season and the level of pollution are significant factors affecting the health of parous women and their offspring. The reason why HLHS and SV develop more frequently at certain times of the year remains unclear, therefore research on this topic should be continued, as well as on the effects of PM10 and benzo(a)pyrene exposure.

Associations between weekly air pollution exposure and congenital heart disease

BACKGROUND

The topic of congenital heart diseases (CHDs) has attracted more and more attentions. Accumulating evidence suggests that exposure to air pollutants during pregnancy is associated with CHDs, yet the results are inconsistent and study about weekly exposure is few. Our study evaluated the association between weekly air pollution and CHDs in Hefei, China.

MATERIALS AND METHODS

Daily CHDs admission data were obtained from eight hospitals in Hefei from October 2015 to September 2017. Meteorological data and air quality were collected from China Meteorological Data Network. Distributed lag nonlinear model (DLNM) considering both the lag effect of exposure factors and the nonlinear relationship of exposure-reaction was used to assess the effect of weekly air pollutants exposure on CHDs admission.

RESULTS

During the study period, totally 47,046 cases of perinatal infants were recruited, and the incidence of CHDs was 9.71 per thousand. The findings showed PM_2.5, PM₁₀, SO₂ and NO₂ significantly increased the risk of CHDs. Each 10 μg/m³ increase in PM_2.5 during gestational weeks 20-26 increased the risk of CHDs. The susceptibility windows of PM₁₀ (weeks 0-2 and weeks 25-29 of pregnancy), SO₂ (weeks 8-16 and weeks 29-38) and NO₂ (week 40), while the strongest effects of these 4 pollutants on CHDs were observed in week 22 (RR = 1.034, 95% CI: 1.007-1.062), week 0 (RR = 1.081, 95% CI: 1.02-1.146), week 37 (RR = 1.528, 95% CI: 1.085-2.153) and week 40 (RR = 1.171, 95% CI: 1.006-1.364), respectively.

CONCLUSIONS

Air pollutants (SO₂, NO₂, PM₁₀, and PM_2.5) exposure could increase the risk of CHDs, while the most crucial susceptibility windows for the exposure were mainly in the second and third trimesters. Boys seemed to be more sensitive to air pollution. Our study contributes to the knowledge of the association between maternal exposure to air pollution and CHDs, but the associations need to be verified by further studies.