Prenatal lead exposure and fetal growth: Smaller infants have heightened susceptibility.

2017

228-233

2017 Feb

1873-6750

<p><strong>BACKGROUND: </strong>As population lead levels decrease, the toxic effects of lead may be distributed to more sensitive populations, such as infants with poor fetal growth.</p>

<p><strong>OBJECTIVES: </strong>To determine the association of prenatal lead exposure and fetal growth; and to evaluate whether infants with poor fetal growth are more susceptible to lead toxicity than those with normal fetal growth.</p>

<p><strong>METHODS: </strong>We examined the association of second trimester maternal blood lead levels (BLL) with birthweight-for-gestational age (BWGA) z-score in 944 mother-infant participants of the PROGRESS cohort. We determined the association between maternal BLL and BWGA z-score by using both linear and quantile regression. We estimated odds ratios for small-for-gestational age (SGA) infants between maternal BLL quartiles using logistic regression. Maternal age, body mass index, socioeconomic status, parity, household smoking exposure, hemoglobin levels, and infant sex were included as confounders.</p>

<p><strong>RESULTS: </strong>While linear regression showed a negative association between maternal BLL and BWGA z-score (β=-0.06 z-score units per log BLL increase; 95% CI: -0.13, 0.003; P=0.06), quantile regression revealed larger magnitudes of this association in the &lt;30th percentiles of BWGA z-score (β range [-0.08, -0.13] z-score units per log BLL increase; all P values&lt;0.05). Mothers in the highest BLL quartile had an odds ratio of 1.62 (95% CI: 0.99-2.65) for having a SGA infant compared to the lowest BLL quartile.</p>

<p><strong>CONCLUSIONS: </strong>While both linear and quantile regression showed a negative association between prenatal lead exposure and birthweight, quantile regression revealed that smaller infants may represent a more susceptible subpopulation.</p>

10.1016/j.envint.2016.11.023

Environ Int

27923585

Prenatal Stress, Methylation in Inflammation-Related Genes, and Adiposity Measures in Early Childhood: the Programming Research in Obesity, Growth Environment and Social Stress Cohort Study.

2018

34-41

2018 01

1534-7796

<p><strong>OBJECTIVE: </strong>Maternal stress during pregnancy may influence childhood growth and adiposity, possibly through immune/inflammatory programming. We investigated whether exposure to prenatal stress and methylation in inflammation-related genes were associated with childhood adiposity in 424 mother-child pairs in Mexico City, Mexico.</p>

<p><strong>METHODS: </strong>A stress index was created based on four prenatally administered stress-related scales (Exposure to Violence, Crisis in Family Systems, State-Trait Anxiety Inventory, and Edinburgh Postnatal Depression Scale). We measured weight, height, body fat mass (BFM), percentage body fat (PBF), and waist circumference in early childhood (age range, 4-6 years). Body mass index (BMI) z scores were calculated according to World Health Organization standards. DNA methylation in gene promoters of tumor necrosis factor α, interleukin 8, and interleukin 6 (IL6) in umbilical cord blood were determined by pyrosequencing.</p>

<p><strong>RESULTS: </strong>An interquartile range increase in stress index (27.3) was associated with decreases of 0.14 unit in BMI z score (95% confidence interval [CI] = -0.28 to -0.005), 5.6% in BFM (95% CI = -9.7 to -1.4), 3.5% in PBF (95% CI = -6.3 to -0.5), and 1.2% in waist circumference (95% CI = -2.4 to -0.04) in multivariable-adjusted models. An interquartile range increase in IL6 methylation (3.9%) was associated with increases of 0.23 unit in BMI z score (95% CI = 0.06-0.40), 8.1% (95% CI = 2.3-14.3) in BFM, 5.5% (95% CI = 1.7-9.5) in PBF, and 1.7% (95% CI = 0.2-3.3) in waist circumference.</p>

<p><strong>CONCLUSIONS: </strong>Prenatal stress was associated with decreased childhood adiposity, whereas cord blood IL6 methylation was associated with increased childhood adiposity in Mexican children.</p>

10.1097/PSY.0000000000000517

Psychosom Med

28787364