Abstract

BACKGROUND AND AIM[|]Urban biodiversity has a profound impact on human health that has not been thoroughly investigated. Little research exists regarding the associations between plant species richness and preterm birth (PTB). We aimed to examine the relationships between PTB and plant species richness, and the effect modifications by maternal characteristics, air pollution, ambient temperature, and the coronavirus disease (COVID-19) pandemic.[¤]METHOD[|]Clinical and sociodemographic data were obtained from Kaiser Permanente Southern California electronic health records in 2015–2021. PTB was defined as gestational age at birth less than 37 weeks. Maternal residential plant species diversity data were extracted from a wild vascular plant species diversity map across California urban areas at 5km resolution, and the maternal residential green space exposure data were assessed from satellite-based images (Normalized Difference Vegetation Index (NDVI) and land-cover green space). Multilevel logistic regressions were applied to examine the association between PTB and plant species diversity, after controlling for maternal age, race/ethnicity, education, and median household income. We also examined the effect modifications by maternal characteristics, air pollution, ambient temperature, and COVID pandemic (delivery before or during the pandemic) factors.[¤]RESULTS[|]In total, we included 302,266 births occurring between January 1, 2015, and December 31, 2021, with 21,421 (7.1%) PTB cases. Plant species richness in 2500m buffer showed a protective association with PTB (odds ratio [OR]: 0.980, 95% CI: 0.964, 0.996). The association persisted after further adjustments for NDVI and land-cover green space. The risk of PTB associated with plant species richness were significantly lower among mothers having a college degree, living in neighborhood with higher levels of O3 and average ambient temperature, and during the pandemic.[¤]CONCLUSIONS[|]This study found that maternal exposure to higher plant species diversity was associated with a decreased risk of PTB. Our findings suggest a complex interplay of sociodemographic and environmental factors influencing PTB risks.[¤]