Effect of vitamin A on the relationship between maternal thyroid hormones in early pregnancy and fetal growth: A prospective cohort study

Abstract

BackgroundFetal growth patterns are influenced by maternal thyroid function and vitamin A level during pregnancy. Vitamin A presents interactions with thyroid tissues and hormonal systems. We examined whether vitamin A status modified the associations of maternal thyroid hormones in early pregnancy and fetal growth outcomes among euthyroid pregnant women in a prospective cohort study (n = 637).MethodsWe performed multiple linear regression and multinomial logistic regression analysis to investigate the effects of thyroid hormones in early pregnancy on fetal growth according to different levels of serum vitamin A based on median value.ResultsA 1 pmol/L increase in maternal free triiodothyronine (FT3) levels was associated with an increased birth weight of 0.080 kg (p = 0.023) in women with lower maternal vitamin A levels in early pregnancy. Increased maternal free thyroxine (FT4) was associated with decreased odds for both small size for gestational age (SGA) [odds ratios (OR) = 0.66, 95% confidence interval (CI): 0.45–0.95] and large size for gestational age (LGA) (OR = 0.66, 95% CI: 0.45–0.98) in women with higher vitamin A level in early pregnancy after adjustment for maternal prepregnancy body mass index, gestational weight gain, maternal employed, parity, gestational week at sampling, and gestational diabetes mellitus.ConclusionsIn Chinese pregnant women without overt thyroid dysfunction, maternal FT4 in early pregnancy was positively associated with optimal fetal growth among women with higher serum vitamin A concentrations.

Birth Weight and Third-trimester Maternal Vitamins A, C, and E Levels

“…Therefore, there is a need for follow-up of the study participants and their infants to verify the role intra-uterine vitamin depletions play as an etiologic factor of chronic diseases at the adult stage of life. Vitamins A and E are both fat-soluble with overlapping roles from embryonic to fetal development [31][32][33], yet not one but both were depleted at the third trimester. Furthermore, that these results should be of concern are several factors and deleterious situations that cut across age groups already mitigating against the health and well-being of individuals in the different communities where the participants were recruited [34][35][36][37].…”

Pre-pregnancy body mass index, gestational diabetes mellitus, and gestational weight gain: individual and combined effects on fetal growth

“…This study was conducted within a prospective cohort, which initiated to investigate the association of maternal overweight/obesity with infant growth and neurocognitive development from 2016 in Beijing Daxing Maternal and Child Care Hospital ( 17 ). Nine hundred eighty-six participants were recruited in the first trimester and 810 followed to delivery.…”