Relationships of First-Trimester Body Mass Index and Weight Change with Persistent Organic Pollutant Concentrations in Pregnant Canadian Individuals
Bibliographic record
Abstract
Abstract Background Persistent organic pollutants (POPs) are toxic chemicals with demonstrable effects on pregnancy and neonatal outcomes. The associations of early pregnancy body mass index (BMI) and antenatal weight changes with circulating POP concentrations are poorly understood in the Canadian context. The objective of this study is thus to examine the relationships between first trimester maternal BMI, weight change from pre-pregnancy to 6-13 weeks of pregnancy (early gestational weight change), and first trimester plasma POP concentrations among Canadian pregnant women. Methods We conducted a secondary analysis of data collected as part of the Maternal-Infant Research on Environmental Chemicals (MIREC) Study. We determined the POP concentrations across first trimester BMI category (underweight/normal weight, overweight, class I & II obese, and class III obese) and early gestational weight change categories (weight loss, weight neutral/gain) and tested for overall differences using Kruskal-Wallis tests. Associations between first trimester maternal BMI and early gestational weight changes with the plasma concentrations of 41 POPs measured in the first trimester were further evaluated using unadjusted and adjusted censored regression models. Results Eleven of 41 POPs were detectable in at least 50% of the MIREC participants and could be analyzed for their relationships with first trimester BMI and weight change. The majority of POPs were inversely associated with first trimester BMI after controlling for the main confounding variables. Although not statistically significant, POP plasma concentrations tended to be generally higher in participants who lost weight compared to those who gained weight or whose weight stayed relatively stable from pre-pregnancy into the first trimester. Conclusions Our findings lend support to the hypothesis that pregnant women with obesity may have higher bioaccumulation of POPs within their adipose tissues than normal weight pregnant women. Additionally, early gestational weight loss appears to be associated with the highest circulating POP levels. Future studies should focus on the effect of weight changes on POPs concentrations across trimesters.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".