Cord blood lipid mediator profiles associated with maternal passive smoking during pregnancy

Maternal passive smoking (PS) during pregnancy remains a common environmental exposure associated with adverse perinatal outcomes. However, its effects on fetal lipid mediator profiles have not been fully characterized.

To investigate whether maternal PS during pregnancy is associated with alterations in umbilical cord blood lipid mediator profiles in term neonates.

We retrospectively analyzed umbilical cord blood samples from 56 term neonates, comprising 17 born to mothers with documented PS exposure and 39 born to mothers without PS exposure. Targeted lipid mediator profiling was performed using liquid chromatography-tandem mass spectrometry. Orthogonal partial least squares discriminant analysis, univariate analyses with Benjamini-Hochberg false discovery rate correction, receiver operating characteristic curve analysis, and exploratory multivariable linear regression were performed.

Four lipid mediators showed nominal differences between the groups, with higher levels of 14,15-LTE₄, platelet-activating factor, and 13-HpODE and lower levels of oleoylethanolamide (OEA) in the PS-exposed group. However, none remained statistically significant after correction for multiple comparisons. OEA was subsequently evaluated in post-hoc exploratory multivariable analysis and remained associated with maternal PS exposure after adjustment for maternal pre-pregnancy BMI and diabetes mellitus.

This exploratory study identified several candidate cord blood lipid mediator signals related to maternal PS exposure, although none remained statistically significant after correction for multiple comparisons. These findings are hypothesis-generating but suggest that lipid mediator pathways involved in inflammatory and metabolic signaling may warrant further investigation in relation to prenatal tobacco smoke exposure.