Maternal residential greenness and congenital heart defects in infants: A large case-control study in Southern China

Zhiqiang Nie, Boyi Yang, Yanqiu Ou, Michael S. Bloom, Fengzhen Han, Yanji Qu, Philip Nasca, Rosemary Matale, Jinzhuang Mai, Yong Wu, Xiangmin Gao, Yuming Guo, Iana Markevych, Yuxuan Zou, Shao Lin, Guanghui Dong, Xiaoqing Liu

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background: Proximity to greenness has shown protective effects on coronary heart diseases by limiting exposure to environmental hazards, encouraging physical activity, and reducing mental stress. However, no studies have previously evaluated the impacts of greenness on congenital heart defects (CHDs). We examined the association between maternal residential greenness and the risks of CHDs. Methods: We conducted a case-control study (8042 children with major CHDs and 6887 controls without malformations) in 21 cities in Southern China, 2004 – 2016. CHDs cases were diagnosed and verified by obstetrician, pediatrician, or pediatric cardiologists, within one year. We estimated maternal residential greenness using satellite-derived normalized difference vegetation index (NDVI) in zones of 500 meters (m) and 1000 m surrounding participants’ residences. Logistic regression models were used to assess NDVI-CHD relationships adjusting for confounders. Results: Interquartile range NDVI increases within 500 m or 1000 m were associated with odds ratios (OR) of 0.95 (95% confidence interval (CI): 0.92, 0.98) and 0.94 (95%CI: 0.91, 0.97) for total CHDs respectively. Air pollutants mediated 52.1% of the association. We also identified a protective threshold at 0.21 NDVI on CHD. Similar protective effects from greenness were found in most CHDs subtypes. The protective associations were stronger for fall, urban or permanent residents, higher household income maternal age ≤35 years of age, and high maternal education (ORs: ranged from 0.85 to 0.96). Conclusion: Our findings suggest a beneficial effect of maternal residential greenness on CHDs. Further studies are needed to confirm our findings, which will help to refine preventive health and urban design strategies.

Original languageEnglish
Article number105859
Number of pages11
JournalEnvironment International
Volume142
DOIs
Publication statusPublished - Sep 2020
Externally publishedYes

Keywords

  • Congenital heart defects
  • Greenness
  • Pregnant women

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