Folic Acid Supplementation and the Association between Maternal Airborne Particulate Matter Exposure and Preterm Delivery: A National Birth Cohort Study in China

Abstract

Background: Potential modification of the association between maternal particulate matter (PM) exposure and preterm delivery (PTD) by folic acid (FA) supplementation has not been studied. Objective: We examined whether FA supplementation could reduce the risk of PTD associated with maternal exposure to PM in ambient air during pregnancy. Method: In a cohort study covering 30 of the 31 provinces of mainland China in 2014, 1,229,556 primiparas of Han ethnicity were followed until labor. We collected information on their FA supplementation and pregnancy outcomes and estimated each participant’s exposure to PM with diameters of ( ), ( ), and ( ) using satellite remote-sensing based models. Cox proportional hazard regression models were used to examine interactions between FA supplementation and PM exposures, after controlling for individual characteristics. Results: Participants who initiated FA prior to pregnancy (38.1%) had a 23% [hazard ratio (95% CI: 0.76, 0.78)] lower risk of PTD than women who did not use preconception FA. Participants with PM concentrations in the highest quartile had a higher risk of PTD [ (95% CI: 1.26, 1.32) for , 1.52 (95% CI: 1.46, 1.58) for , and 1.22 (95% CI: 1.17, 1.27) for ] than those with exposures in the lowest PM quartiles. Estimated associations with a increase in and were significantly lower among women who initiated FA prior to pregnancy [ (95% CI: 1.08, 1.10) for both exposures] than among women who did not use preconception FA [ (95% CI: 1.11, 1.13) for both exposures; ]. The corresponding association was also significantly lower for a increase in [ (95% CI: 1.02, 1.03) for FA before pregnancy vs. 1.04 (95% CI: 1.03, 1.04) for no preconception FA; ]. Conclusion: Our findings require confirmation in other populations, but they suggest that initiating FA supplementation prior to pregnancy may lessen the risk of PTD associated with PM exposure during pregnancy among primiparas of Han ethnicity. https://doi.org/10.1289/EHP6386

Association between blood metals mixtures concentrations and cognitive performance, and effect modification by diet in older US adults

“…Recent findings suggest a potential protective effect of folic acid, an antioxidant component of the diet; against effects of phthalate metabolites, 22 pesticides 23 and air pollutants 24 on autistic traits 24 and intellectual abilities in children, 25 or on the risk of preterm birth. 26 However, to our knowledge, no study evaluated similar patterns for other environmental contaminants on cognitive performance among the elderly. In this investigation, we hypothesized that a high-diet quality or adherence to an anti-inflammatory dietary pattern may attenuate inflammation and subsequently reduce the metals-induced neurotoxicity.…”

Metabolism-Disrupting Chemical Mixtures during Pregnancy, Folic Acid Supplementation, and Liver Injury in Mother-Child Pairs

“…FA supplementation has been shown to attenuate MDCassociations (i.e. air pollutants, phthalates) with adverse birth [15] and neurodevelopmental outcomes, [16] but its potential modifying role in MDC associations with liver injury has not been studied.…”

Periconceptional Folic Acid Use and Its Effects on Neural Tube Defects — Five Counties, Shanxi Province, China, 2010–2016

“…The program aimed to motivate 70% of women to commence folic acid supplementation at least three months before conception ( 3 - 4 ). However, studies have indicated suboptimal adherence levels (below 40%), significantly short of the MOH’s target ( 5 - 6 ), though the degree of adherence noticeably improved with higher maternal educational levels ( 6 ). This study investigates the use of folic acid, its protective effect against NTDs, and the significant features influencing adherence to the supplementation protocol in five counties within China’s Shanxi Province following the rollout of the national supplementation program.…”