Prenatal lignan exposures, pregnancy urine estrogen profiles and birth outcomes

During pregnancy, human exposure to endogenous estrogens and xenoestrogens (such as lignans) may comprehensively impact the gestational maintenance and fetal growth. We measured the concentrations of 5 lignans and the profile of 13 estrogen metabolites (EMs) in the urine samples of 328 pregnant women and examined their associations with birth outcomes. We found significantly positive associations between gestational age and urinary matairesinol (MAT), enterodiol (END) and enterolactone (ENL), as well as 16-hydroxylation pathway EMs. There were consistently positive relationships between END and the 16-hydroxylation pathway EMs. The positive relationships of MAT, END and ENL exposures with the length of gestation were mainly in the low exposure strata of the levels of these EMs. This study reveals that MAT, END and ENL as well as 16-hydroxylation pathway EMs are associated with birth outcomes, and that there are interactive relationships between lignans and 16-hydroxylation pathway EMs with birth outcomes.