Associations of PM2.5 and its components with term preterm rupture of membranes: a retrospective study.

Abstract

Background: There is evidence that fine particulate matter (PM_2.5) exposure is associated with premature rupture of membranes (PROM); however, studies of its effect on term PROM (TPROM) are limited, and the results are inconsistent.

Objective: This study aimed to investigate the association between exposure to PM_2.5 and its components and the risk of TPROM.

Methods: From 2018 to 2022, we collected delivery data from pregnant women in Guangzhou. Using 1:1 case matching, we included 1,216 TPROM cases and 1,216 controls. PM_2.5 and its component concentrations were obtained from Tracking Air Pollution in China. The time-varying mean concentration method was used to estimate exposure to PM_2.5 and its components during different trimesters. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) to evaluate the associations of exposure to PM_2.5 and its components with the risk of TPROM.

Results: The incidence of TPROM in this study was 19.66%. After adjusting for potential confounders, statistically significant associations were found between TPROM and exposure to PM_2.5, nitrate ( ${\mathrm{NO}}_3^{-}$ ), ammonium ( ${\mathrm{NH}}_4^{+}$ ), and black carbon (BC) during the second trimester and between TPROM and exposure to PM_2.5, sulphate ( ${\mathrm{SO}}_4^{2-}$ ), and BC during the third trimester. Specifically, the interquartile range (IQR) 3 (IQR3) and IQR4 of ${\mathrm{SO}}_4^{2-}$ exposure during the third trimester increased the risk of TPROM by 18% (95% CIs [1.01-1.39]) and 18% (95% CIs [1.01-1.39]), respectively. A nonlinear relationship was observed between exposure to PM_2.5, ${\mathrm{SO}}_4^{2-}$ , ${\mathrm{NH}}_4^{+}$ , and OM during the second trimester and the risk of TPROM. No significant interactions were found between PM_2.5 and its components with TPROM across various subgroups.

Conclusion: Our findings indicate significant associations between the risk of TPROM and exposure to PM_2.5 and several of its components during pregnancy. Contribute to the literature on the associations of PM_2.5 and its components with TPROM.