Influence of residential greenness on adverse pregnancy outcomes: A systematic review and dose-response meta-analysis

Sci Total Environ. 2020 May 20:718:137420. doi: 10.1016/j.scitotenv.2020.137420. Epub 2020 Feb 19.

Abstract

Background: With the development of urbanization, there is a decreasing tendency for people contact with natural greenness. Whether maternal exposure to greenness has an impact on pregnancy complications and pregnancy outcomes remains to be confirmed.

Objectives: To estimate the association and dose-response relationship between residential greenness and pregnancy outcomes.

Data sources: PubMed, Embase, Ovid, Scopus and Web of Science from inception to 1st December 2019 were searched.

Synthesis methods: The summary regression coefficient (β) and odds ratio (OR) with corresponding 95% confidence interval (95%CI) were calculated. The linear dose-response relationship between greenness and adverse pregnancy outcomes was also investigated.

Results: Overall, 36 studies with a total of 11,983,089 participants were included. Birth weight was significantly higher in highest level of greenness exposure group compared to lowest level group (e.g. β:20.22, 95%CI:13.50-26.93 at 100 m buffer). The odds of low birth weight (LBW) decreased in the highest level of group compared to lowest level group (e.g. OR:0.86, 95%CI:0.75-0.99 at 100 m buffer). The odds of small for gestational age (SGA) also decreased in the highest group (OR:0.93, 95%CI:0.88-1.00 at 100 m buffer). In addition, maternal exposure to greenness was associated with increased head circumference and decreased mental disorders. The dose-response models showed a 2% decrease risk of LBW per 0.1 normalized difference vegetation index (NDVI) increase within 300 m buffer (OR:0.98, 95%CI:0.97-0.99, P < 0.001) and a 1% decrease risk of SGA per 0.1 NDVI increase within 300 m buffer (OR:0.99, 95%CI:0.98-1.00, P = 0.037). No significant associations were found on preterm birth, gestational age, gestational diabetes mellitus, gestational hypertension or preeclampsia.

Conclusions: This review confirms an inverse association between residential greenness and adverse pregnancy outcomes. Findings of our study provide evidences for pregnant women to increase greenness exposure.

Keywords: Birth outcomes; Dose-response; Greenness; Meta-analysis; Pregnancy outcomes.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Birth Weight
  • Female
  • Gestational Age
  • Humans
  • Infant, Low Birth Weight
  • Infant, Newborn
  • Pregnancy
  • Pregnancy Outcome*
  • Socioeconomic Factors