Maternal oxidative stress biomarkers across pregnancy in relation to fetal growth: evidence from the TIDES cohort.

Oxidative stress (OS), an imbalance between reactive oxygen species and antioxidants, has been linked to impaired placental function and suboptimal fetal growth, yet trimester-specific associations remain poorly understood. We examined 561 mother-infant pairs from The Infant Development and Environmental Study, measuring maternal urinary biomarkers of DNA oxidation (8-hydroxydeoxyguanosine (8-OHdG)), lipid peroxidation (malondialdehyde (MDA) and F2-isoprostanes), and protein oxidation (dityrosine (diY)) at first and second trimesters. Using generalized linear models, we examined prospective associations between OS and ultrasound-derived growth velocities. Early pregnancy OS biomarkers were persistently associated with reduced second and third trimester growth velocities. First trimester lipid peroxidation markers (8-PGF2α, 15-PGF2α, and 8,15-PGF2α) were associated with slower estimated fetal weight (EFW) growth velocity in both second trimester (-0.81, -0.93, and -1.72 g/week per log-unit increase, respectively) and third trimester (-4.25, -5.60, and -6.74 g/week). Similarly, first trimester 8-OHdG and diY were associated with both second trimester (-1.31 and -1.17 g/week, respectively) and third trimester EFW velocity (-8.01 and -6.75 g/week, respectively). Second trimester 8-OHdG and MDA were associated with slower third trimester EFW velocity (-8.57 and -9.25 g/week, respectively). These results provide novel insights into trimester-specific associations between OS and fetal growth.