Association between environmental noise exposure during pregnancy and the risk of preterm birth: evidence from a...

There is heterogeneity in the results on prenatal noise exposure and preterm birth risk. Moreover, the health influence of extreme noise (high transients of noise) and noise variability (fluctuation in the intensity) remains unknown. This study aims to investigate the association of prenatal average environmental noise, extreme noise, and noise variability with preterm birth.

Using equivalent continuous A-weighted sound pressure level (L_Aeq) data from 100 monitoring sites in Guangzhou, China, the maximum instantaneous A-weighted sound level (L_Amax), the 10th percentile of noise level (L_A10), and the 90th percentile of noise level (L_A90) were calculated. Based on the built environmental noise land use regression models, L_Amax, L_A10, and L_A90 prediction models were constructed. Participants' annual average daytime and nighttime L_Aeq, L_Amax, L_A10, and L_A90 levels were fitted, and noise climate (NC) and noise exposure index (NEI) were calculated. In this retrospective cohort study, logistic regression was used to examine the associations with preterm birth, reporting odds ratios (OR) and 95 % confidence intervals (CI). A meta-analysis contextualized the results.

A total of 2762 participants were included, with an average age of 29.34 ± 4.88 years and a preterm birth rate of 1.48 % (41/2762). After adjusting for confounding, NEI (OR = 1.98, 95 %CI: 1.00, 3.91, P = 0.049), L_Aeq,day (OR = 1.37, 95 %CI: 1.03, 1.82, P = 0.030), L_Amax,day (OR = 1.39, 95 %CI: 1.05, 1.84, P = 0.021), and NC_day (OR = 1.41, 95 %CI: 1.10, 1.82, P = 0.008) were significantly associated with the risk of preterm birth. L_{Aeq, night} (OR = 1.26, 95 %CI: 0.97, 1.63, P = 0.084) and L_{Amax, night} (OR = 1.26, 95 %CI: 0.97, 1.64, P = 0.084) showed a marginally significant association with increased preterm birth risk. Meta-analysis confirmed a significant pooled association (OR = 1.02, 95 %CI: 1.01, 1.03, P < 0.001), with moderate heterogeneity (I² = 50.90 %, P = 0.021).

Environmental noise was significantly associated with the risk of preterm birth. The current study highlights the importance of addressing environmental noise pollution in women at high risk for preterm birth.