Report on Prenatal Exposure to Melamine, Aromatic Amines, and Psychosocial Stressors and Their Association with Gestational Diabetes Mellitus (GDM)

Introduction

Exposure to chemical and non-chemical stressors during pregnancy poses significant risks to maternal and fetal health, including the development of gestational diabetes mellitus (GDM). Melamine, a widely used industrial chemical, and aromatic amines (AAs), found in various environmental sources, are ubiquitous among pregnant populations. Despite this, limited research has explored their prenatal health effects. This study investigates the associations between prenatal exposure to melamine, aromatic amines, psychosocial stressors, and GDM within a pregnancy cohort in San Francisco, California, USA.

Objectives

1. Evaluate the relationships between exposure to aromatic amines, melamine and its derivatives, and gestational diabetes.
2. Explore the modifying effects of non-chemical stressors such as financial strain and psychosocial stress.
3. Assess fetal sex differences in these associations through stratification.

Methods

Study Population and Data Collection

The study analyzed data from 607 pregnant women enrolled in the Chemicals in Our Bodies (CIOB) cohort, part of the NIH’s Environmental Influences on Child Health Outcomes (ECHO) program. Participants were recruited during their second trimester and provided urine samples and completed questionnaires assessing demographics, financial strain, perceived stress, depressive symptoms, and experiences of discrimination. GDM status was obtained from medical records.

Chemical Exposure Assessment

• Urine samples were analyzed for 36 aromatic amines, melamine, and three melamine derivatives using high-performance liquid chromatography-tandem mass spectrometry.
• Specific gravity adjustments were applied to account for urine dilution.
• Analytes detected in less than 20% of samples were excluded from analyses.

Statistical Analysis

• Logistic regression models estimated odds ratios (ORs) for GDM associated with interquartile range increases in urinary chemical concentrations and levels of non-chemical stressors.
• Models were adjusted for maternal age, race/ethnicity, education, and parity where appropriate.
• Effect modification by fetal sex and interactions between chemical and non-chemical stressors were evaluated.

Results

Participant Characteristics

• Mean maternal age was 33 years; 42% identified as White, 30% as Latinx/Hispanic.
• Fifteen percent of participants were diagnosed with GDM.
• Psychosocial stress levels and experiences of discrimination varied by race/ethnicity.

Chemical Exposure Findings

• Melamine and cyanuric acid were detected in 100% of participants; ammelide in 99%.
• Eight aromatic amines were detected in ≥20% of samples and included in analyses.
• Higher summed urinary concentrations of melamine and its analogs were associated with increased odds of GDM among pregnant women carrying male fetuses (OR: 1.08 per IQR increase).
• O-Anisidine, an aromatic amine, was also linked to higher GDM odds in male fetuses (OR: 1.18 per IQR increase).

Non-Chemical Stressors and GDM

• Higher perceived stress and experiences of discrimination were associated with increased odds of GDM (OR: 1.41 and 2.33 respectively for highest stress/discrimination levels).
• Financial strain showed no significant association with GDM.

Interaction Effects

• Limited evidence of interaction between chemical exposures and non-chemical stressors was observed.
• Some indications that discrimination may modify the effect of certain chemicals (e.g., aniline, p-Toluidine) on GDM risk.

Discussion

This study highlights the ubiquitous exposure to melamine, its analogs, and aromatic amines among pregnant women and their potential role in increasing GDM risk, particularly in pregnancies with male fetuses. The findings align with Sustainable Development Goal (SDG) 3: Good Health and Well-being, emphasizing the importance of reducing environmental health risks to improve maternal and child health outcomes.

Biological mechanisms may involve endocrine disruption, oxidative stress, inflammation, and metabolic dysfunction, which are critical areas for further research. The association of psychosocial stressors such as perceived stress and discrimination with GDM underscores the relevance of SDG 10: Reduced Inequalities, advocating for the elimination of disparities in health outcomes linked to social determinants.

Environmental justice considerations are central to this research, as chemical and psychosocial stress exposures disproportionately affect marginalized communities. Addressing these exposures supports SDG 5: Gender Equality and SDG 11: Sustainable Cities and Communities by promoting safe environments for pregnant individuals.

Conclusion

In conclusion, this study provides evidence of associations between prenatal exposure to melamine, aromatic amines, psychosocial stressors, and gestational diabetes mellitus. These findings emphasize the need for integrated public health strategies to mitigate chemical and psychosocial stress exposures during pregnancy, contributing to the achievement of multiple Sustainable Development Goals, including SDG 3 (Good Health and Well-being), SDG 5 (Gender Equality), and SDG 10 (Reduced Inequalities).

Future research should focus on longitudinal assessments, diverse populations, and elucidation of biological mechanisms to inform effective interventions and policies.

1. Sustainable Development Goals (SDGs) Addressed or Connected to the Issues Highlighted in the Article

1. SDG 3: Good Health and Well-being
   • The article focuses on maternal and fetal health, specifically gestational diabetes mellitus (GDM), which is a significant health concern during pregnancy.
   • It addresses exposure to chemical and non-chemical stressors affecting pregnancy outcomes.
2. SDG 10: Reduced Inequalities
   • The study highlights disparities in exposure to melamine and aromatic amines among Hispanic and non-Hispanic Black pregnant women.
   • It discusses the role of psychosocial stressors such as discrimination, which relates to social inequalities.
3. SDG 12: Responsible Consumption and Production
   • The article discusses widespread use and exposure to industrial chemicals like melamine and aromatic amines, emphasizing the need for safer chemical management.

2. Specific Targets Under Those SDGs Identified Based on the Article’s Content

1. SDG 3: Good Health and Well-being
   • Target 3.1: Reduce the global maternal mortality ratio.
   • Target 3.3: End epidemics of communicable diseases and reduce burden of non-communicable diseases, including diabetes.
   • Target 3.9: Reduce the number of deaths and illnesses from hazardous chemicals and air, water, and soil pollution and contamination.
2. SDG 10: Reduced Inequalities
   • Target 10.2: Empower and promote the social, economic and political inclusion of all, irrespective of race, ethnicity, or other status.
   • Target 10.3: Ensure equal opportunity and reduce inequalities of outcome, including by eliminating discriminatory practices.
3. SDG 12: Responsible Consumption and Production
   • Target 12.4: Achieve environmentally sound management of chemicals and all wastes throughout their life cycle.
   • Target 12.5: Substantially reduce waste generation through prevention, reduction, recycling and reuse.

3. Indicators Mentioned or Implied in the Article to Measure Progress Towards the Identified Targets

1. Health Indicators Related to SDG 3
   • Prevalence and incidence rates of gestational diabetes mellitus (GDM) among pregnant women.
   • Urinary concentrations of melamine, aromatic amines, and their derivatives as biomarkers of chemical exposure.
   • Measures of psychosocial stress including perceived stress scale (PSS-4), depressive symptoms (CES-D-10), and self-reported experiences of discrimination.
   • Odds ratios (OR) of GDM associated with chemical and non-chemical stressors, stratified by infant sex.
2. Indicators Related to SDG 10
   • Disparities in chemical exposure levels and psychosocial stressors by race/ethnicity.
   • Self-reported frequency of discrimination experiences.
3. Indicators Related to SDG 12
   • Detection frequency and concentration levels of melamine and aromatic amines in human biological samples (urine, breast milk).
   • Monitoring of chemical usage and exposure in populations.

4. Table of SDGs, Targets, and Indicators Relevant to the Article

Source: nature.com