Associating phthalate exposure during pregnancy with preschooler's FMI, ABSI and BRI trajectories via putative mechanism pathways.

Phthalates are well-known obesogens, but a few studies have explored their impacts on the childhood fat mass index (FMI), body shape index (ABSI) and body roundness index (BRI). Information from 2950 participants recruited in the Ma'anshan Birth Cohort was analyzed. The relationships between six maternal phthalate metabolites and their mixture and childhood FMI, ABSI and BRI were investigated. FMI, ABSI and BRI in children aged 3.5 y, 4.0 y, 4.5 y, 5.0 y, 5.5 y and 6.0 y were calculated. The latent class trajectory modeling categorized the FMI trajectories into "rapidly increasing FMI" (4.71%) and "stable FMI" (95.29%) groups; ABSI trajectories were categorized as "decreasing ABSI" (32.74%), "stable ABSI" (46.55%), "slowly increasing ABSI" (13.26%), "moderately increasing ABSI" (5.27%) and "rapidly increasing ABSI" (2.18%) groups; BRI trajectories were categorized as "increasing BRI" (2.82%), "stable BRI" (19.85%), and "decreasing BRI" (77.34%) groups. Prenatal MEP exposure was associated with repeated measurements of FMI (ß = 0.111, 95% CI = 0.002-0.221), ABSI (ß = 0.145, 95% CI = 0.023-0.268) and BRI (ß = 0.046, 95% CI = -0.005-0.097). Compared with each stable trajectory group, prenatal MEP (OR = 0.650, 95% CI = 0.502-0.844) and MBP (OR = 0.717, 95% CI = 0.984-1.015) were linked to a decreased risk of "decreasing BRI" in children; there was a negative relationship between MBP and the "decreasing ABSI" group (OR = 0.667, 95% CI = 0.487-0.914), and MEP increased the risks of "slowly increasing ABSI" (OR = 1.668, 95% CI = 1.210-2.299) and "rapidly increasing ABSI" (OR = 2.522, 95% CI = 1.266-5.024) in children. Phthalate mixture during pregnancy showed significant relationships with all anthropometric indicator trajectories, with MEP and MBP always being of the largest importance. In conclusion, this study suggested that prenatal phthalate coexposure increased the childhood probability of being in higher ABSI and BRI trajectory groups. That is, children were more likely to be obese when they were exposed to higher levels of some phthalate metabolites and their mixture. The low-molecular weight phthalates, including MEP and MBP, contributed the greatest weights.

Combined effects of prenatal phthalate exposure on cardiometabolic risk score among 4- to 7-year-old children: MABC study.

There is currently no consensus about the impact of prenatal phthalate exposure on blood pressure and glycolipids in children. Few studies consider the health effects as an integrated indicator. The combined effect of multiple phthalate exposures is often ignored. Based on the Ma'anshan Birth Cohort, 2298 woman-child pairs were included in this study. Maternal urine was collected in each trimester to analyze 6 phthalate metabolites. The overall cardiometabolic risk (CMR) score was calculated based on serum glycolipids and blood pressure for children aged 4-7 years. A higher score represents a less favorable CMR profile. The restricted cubic spline model was used to explore the relationship between prenatal phthalate exposure and childhood CMR score. In addition, the quantile g-computation and the Bayesian kernel machine regression were used to evaluate the combined effect. The MBP exposure in the 1st trimester (MBP-1st) and the MEP-2nd were non-linearly associated with the CMR score (Fnonlinear = 3.28 and 5.60, Pnonlinear = 0.0378 and 0.0038, respectively). The MBP-3rd (Flinear = 5.31, Plinear = 0.0012) and the ∑LMWP-3rd (Flinear = 4.37, Plinear = 0.0045) were negatively associated with the score in a linear manner. The phthalate mixture in the 2nd trimester increased the score (psil = 0.1747, 95% CI = 0.0077-0.3416), with the MEP being the most common [weights = 0.5290; posterior inclusion probability (PIP) = 0.40]. The phthalate mixture in the 3rd trimester decreased the score (psil = -0.2024, 95% CI = -0.4097－0.0048), with the MEHP (weights = -0.5101; PIP = 0.14) and the MBP (weights = -0.3993, PIP = 1.00) being the greatest contributors. In conclusion, the MBP-1st and the MEP-2nd are non-linearly associated with the cardiometabolic risk in children. The MBP-3rd and the ∑LMWP-3rd decrease the childhood risk. The combined exposure to phthalate mixture in the second and third trimester elevates and decreases the risk of childhood cardiometabolism, respectively.

Prenatal single and combined exposure to phthalates associated with girls' BMI trajectory in the first six years.

Evidence of the influence of prenatal phthalate exposure on childhood longitudinal obesity markers is limited. Nested on the Ma'anshan birth cohort study, 990 mother-daughter pairs were included. Seven phthalate metabolites were determined in urine collected in each trimester. Each child underwent a physical examination from birth to 6 years of age twelve times. Latent class growth models were used to identify three trajectories of girls' body mass index (BMI). Logistic regression, quantile g-computation and Bayesian kernel machine regression models analyzed the relationships of prenatal exposure to individual and mixed phthalates with girls' body mass index (BMI) trajectory. Compared to the "lowest trajectory" class, prenatal average concentrations of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP, ORcrude = 2.095, 95 % CI = 1.014-4.328) and di(2-ethylhexyl) phthalate (DEHP, ORcrude = 2.336, 95 % CI = 1.022-5.338) during pregnancy were associated with an increased probability of being in the "highest trajectory" class. The average concentration of DEHP (ORcrude = 1.879, 95 % CI = 1.002-3.522) was associated with an increased probability of being in the "moderate trajectory" class. Stratified analyses by trimester of pregnancy mainly showed that third-trimester exposure to monoethyl phthalate (MEP, ORadjusted = 1.584, 95 % CI = 1.094-2.292), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP, ORadjusted = 2.885, 95 % CI = 1.367-6.088), MEHHP (ORadjusted = 2.425, 95 % CI = 1.335-4.407), DEHP (ORadjusted = 2.632, 95 % CI = 1.334-5.193) and high molecular weight phthalate (ORadjusted = 2.437, 95 % CI = 1.239-4.792) was associated with an increased probability of being in the "highest trajectory" class. However, the mixture of phthalates was not significantly related to the girl's BMI trajectory. In conclusion, in utero exposure to phthalates, including MEP and DEHP metabolites (MEHHP and MEOHP), was significantly associated with early childhood high BMI trajectories in girls. The third trimester of pregnancy seemed to be the window of vulnerability to phthalate exposure for girls' high BMI trajectory at periods of prenatal development. No evidence supported a significant relationship between combined exposure to phthalate metabolites and girls' high BMI trajectory.

Sex Discrepancy Observed for Gestational Metabolic Syndrome Parameters and Polygenic Risk Associated With Preschoolers' BMI Growth Trajectory: The Ma'anshan Birth Cohort Study.

Background: Few studies have investigated the associations of childhood growth trajectories with the prenatal metabolic risks of mothers and their interaction with children's genetic susceptibility. Objective: To investigate the effects of gestational metabolic syndrome (GMS) risks and children's polygenic risk scores (PRSs), and their interaction effect on the BMI trajectory and obesity risk of offspring from birth to 6 years of age. Methods: A total of 2,603 mother-child pairs were recruited from the Ma'anshan birth cohort (Anhui Province of China) study. Data on maternal prepregnancy obesity, gestational weight gain (GWG), gestational diabetes mellitus (GDM), and hypertensive disorders of pregnancy (HDP) were used to evaluate maternal GMS risk. In addition, 1,482 cord blood samples were used to genotype 11 candidate single-nucleotide polymorphisms (SNPs) to calculate children's PRSs. The latent class growth model using the longitudinal BMI-for-age z scores (BMIz) was applied to validly capture the BMIz growth trajectory. Results: Maternal GMS status was associated with higher BMIz scores and with an increased risk of overweight/obesity. Positive relationships were revealed between PRS and the risk of overweight/obesity among girls. Additionally, maternal GMS significantly interacted with the child's PRS on BMIz scores and the risk of overweight/obesity among girls. Hierarchical BMI trajectory graphs by different exposure groups showed consistent findings, and both boys' and girls' BMIz trajectories were divided into three groups. Among girls, the higher the GMS risk or PRS they had, the higher the probability of being in the high BMIz trajectory group. Conclusions: Maternal GMS status increased BMIz scores and the risk of obesity in both boys and girls and elevated the child's BMI trajectory from birth to 6 years of age among girls. PRSs were significantly associated with children's BMI trajectory and the risk of obesity and modified the associations between maternal GMS status and obesity biomarkers only among girls. Thus, regarding childhood obesity, steps should be taken to decrease maternal metabolic risks before and during pregnancy, and sex discrepancies should be noted to identify high-risk populations after birth to hierarchically manage them.

Relationship of individual and mixed prenatal phthalate exposure with placental structure and efficiency in the prospective Ma'anshan Birth Cohort Study.

BACKGROUND: Few studies have investigated the associations between prenatal phthalate exposure and placental structure and function with inconsistent conclusions. METHODS: Nested on the Ma'anshan Birth Cohort study, 2723 women provided spot urine samples during the first, second and third trimesters of pregnancy to analyze six phthalate metabolites. The outcomes of interest were placental weight, efficiency (birth weight/placental weight), chorionic disc area and disc eccentricity. The relationships of prenatal exposure to a single phthalate with placental measures were analyzed. The associations between prenatal phthalate mixture exposure and placental measures were also evaluated. RESULTS: Most phthalate metabolites were significantly associated with placental weight, efficiency and chorionic disc area during the whole gestation and in each trimester of pregnancy, with different directions of relationships. Sensitivity analyses revealed similar findings, indicating the robustness of the statistical results. Furthermore, inverted U-shaped nonlinear relationships of prenatal exposure to some phthalate metabolites with placental weight, efficiency and chorionic plate area were observed. However, quantile g-computation mixture models did not reveal any association between maternal combined exposure to the total phthalate metabolites and placental measures. CONCLUSIONS: Maternal exposure to most phthalates and their metabolites was associated with placental weight, efficiency and chorionic plate area in both a linear manner and an inverted U-shaped nonlinear manner. However, the mixture of multiple phthalate metabolites was not observed to be associated with any placental measure.

Sex-specific mediation of placental inflammatory biomarkers in the effects of prenatal phthalate coexposure on preschooler cognitive development.

The objective of this study is to investigate the mediating effect of placental inflammatory biomarkers on the relationship between prenatal phthalate coexposure and cognitive development in preschoolers. A subgroup of 1660 mother-child pairs from the Ma'anshan Birth Cohort study were included. We measured the levels of phthalate metabolites of dibutyl phthalate (DBP), butyl benzyl phthalate (BBzP), and di (2-ethylhexyl) phthalate (DEHP) in all the women included in the study from three urine samples collected in each of the trimesters. A potency-weighted sum of coexposure to DBP, BBzP, and DEHP (indicator: ∑PAE) was calculated. The mRNA of the proinflammatory cytokine IL-6 and the classically activated macrophage (M1) biomarker CD68 was analyzed using placental tissues. The Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition-Chinese was used to evaluate the full-scale intelligence quotient (FSIQ) of children aged 2.5-6 years. Average ∑PAEs and ∑PAEs in each trimester were associated with IL-6 and CD68. ∑PAE in the first trimester was positively associated with IL-6 (ß = 0.11, 95% CIs = 0.03-0.19) and CD68 (ß = 0.16, 95% CIs = 0.04-0.28), and negatively associated with FSIQ (ß =-0.06, 95% CIs = -0.11 to -0.02), verbal comprehension (ß =-0.06, 95% CIs = -0.11 to -0.01), and processing speed (ß =-0.07, 95% CIs = -0.12 to -0.01). Additionally, sex discrepancies were observed for the mediating effects of placental inflammation on the relationships between ∑PAE and children's cognitive development. For instance, the association between ∑PAE in early pregnancy and FSIQ was partially mediated by IL-6 (estimated proportion mediated: 21.85%) and CD68 (estimated proportion mediated: 16.2%). Gender-specific associations and trimester-specific relationships of prenatal multiple phthalate coexposure were revealed. ∑PAE in the first trimester of pregnancy was associated with increased of placental inflammation, and a decrease in preschoolers' cognitive development. In boys, placental IL-6 and CD68 elevation resulting from phthalates might be potential mechanisms of poor cognitive development.