The prenatal weekly temperature exposure and neonatal congenital heart disease: a large population-based observational study in China

We aim to explore the link between maternal weekly temperature exposure and CHD in offspring and identify the relative contributions from heat and cold and from moderate and extreme atmospheric temperature. From January 2019 to December 2020, newborns who were diagnosed with CHD by echocardiography in the Network Platform for Congenital Heart Disease (NPCHD) from 11 cities in eastern China were enrolled in the present study. We appraised the exposure lag response relationship between temperature and CHDs in the distributed lag nonlinear model and further probed the pooled estimates by multivariate meta-analysis. We further performed the exposure–response curves in extreme temperature (5(th) percentile for cold and 95(th) for hot events). We also delve into the cumulative risk ratios (CRRs) of temperature on CHDs in general and subgroups. In this study, 5904 of 983, 523 infants were diagnosed with CHDs. The temperature-CHD combination performed positive significance in two exposure windows, gestational weeks 10–16 and 26–31, and reached the maximum effect in the 28th week. Compared with extreme cold (5(th), 6.14℃), these effects were higher in extreme heat (95(th), 29.26℃). The cumulative exposure–response curve showed a steep nonlinear rise in the hot tail but showed non-significance at low temperatures. In this range, the CRRs of temperature showed an increment to a ceiling of 3.781 (95% CI: 1.460–10.723). The temperature- CHD curves for both sex groups showed a general growth trend. No statistical significance was observed between these two groups (P = 0.106). The cumulative effect of the temperature related CHD was significant in regions with lower education levels (maximum CRR was 9.282 (3.019–28.535)). A degree centigrade increase in temperature exposure was associated with the increment of CHD risk in the first and second trimesters, especially in extreme heat. Neonates born in lower education regions were more vulnerable to temperature-related CHDs. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11356-022-24396-5.