# Prenatal exposure to triclosan assessed through repeated urine samples and placental DNA methylation in the SEPAGES cohort

Paulina Jedynak, Lucile Broséus, Jörg Tost, Florence Busato, Stephan Gabet, Cathrine Thomsen, Amrit Sakhi, Isabelle Pin, Rémy Slama, Johanna Lepeule, et al.

<figure><img src="image_1.png" /></figure>

## To cite this version:

Paulina Jedynak, Lucile Broséus, Jörg Tost, Florence Busato, Stephan Gabet, et al. Prenatal exposure to triclosan assessed through repeated urine samples and placental DNA methylation in the SEPAGES cohort. EHP Publishing. ISEE 2022 - 34th Annual Conference of the International Society for Environmental Epidemiology, Sep 2022, Athens, Greece. , ISEE Conference Abstracts: 34th Annual Conference of the International Society of Environmental Epidemiology, 2022 (1), 2022, 10.1289/isee.2022.O-OP-272. hal-04987918

HAL Id: hal-04987918

https://hal.science/hal-04987918v1

Submitted on 12 Mar 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

Public Domain
**Background:** Previously we showed associations between elevated maternal urinary concentrations of triclosan in French pregnant women and increased placental DNA methylation in male fetuses, an effect potentially mediated by placental cell composition. Using a more recent cohort with improved exposure assessment, we aimed to replicate these findings and perform an exploratory study. **Methods:** We assessed triclosan in two pools of 21 urine samples each, collected during the second and third trimester among 395 pregnant women from the SEPAGES cohort. We used Infinium MethylationEPIC arrays to measure DNA methylation in placenta collected at delivery. We used adjusted linear regressions on 500 previously identified candidate CpGs and investigated differentially methylated regions (DMRs) within CpGs overlapping with our previous study. Additionally, we performed an exploratory epigenome-wide association study and DMR analysis on all CpGs available in the assay.

**Results:** In the sex-stratified replication study, we found 75 triclosan-associated genes (three for males and 72 for females including imprinted FBRSL1, KCNQ1, RHOBTB3, and SMOC1). The effect estimates showed a similar pattern to our previous study for females but not males (correlation coefficient rho = 0.75 and 0.07, respectively), with most associations being positive but weaker. When both sexes were considered, 18 triclosan-associated genes were identified. The correlation with effect estimates of our previous study was 0.6. As previously, we showed that placental heterogeneity could mediate the associations between triclosan concentrations and DNA methylation. In the exploratory analysis, we identified only a few isolated sex-specific associations. **Conclusions:** We observed several positive associations between pregnancy triclosan and placental DNA methylation similarly to our previous study, however most of the associations were identified for females but not males. Our results suggest that pregnancy exposure to triclosan could affect placenta through DNA methylation and that female placentas may be particularly vulnerable. **Keywords:** placenta, methylation, pregnancy triclosan, pooled biospecimens