Association between Maternal Exposure to Chemicals during Pregnancy and the Risk of Foetal Death: The Japan Environment and Children's Study

Maternal Exposure to Per- and Polyfluoroalkyl Substances and Offspring Chromosomal Abnormalities: The Japan Environment and Children's Study

BACKGROUND

Although recent in vitro experimental results have raised the question of whether maternal exposure to per- and polyfluoroalkyl substances (PFAS) may be a potential environmental risk factor for chromosomal abnormalities, epidemiological studies investigating these associations are lacking.

OBJECTIVES

This study examined whether prenatal PFAS exposure is associated with a higher prevalence of chromosomal abnormalities among offspring.

METHODS

We used data from the Japan Environment and Children's Study, a nationwide birth cohort study, and employed logistic regression models to examine the associations between maternal plasma PFAS concentrations in the first trimester and the diagnosis of chromosomal abnormalities in all births (artificial abortions, miscarriages, stillbirths, and live births) up to 2 years of age. In addition, we examined associations with mixtures of PFAS using multipollutant models.

RESULTS

The final sample consisted of 24,724 births with singleton pregnancies, of which 44 confirmed cases of chromosomal abnormalities were identified (prevalence: 17.8/10,000 births). When examined individually, exposure to perfluorononanoic acid (PFNA) and perfluorooctane sulfonic acid (PFOS) showed positive associations with any chromosomal abnormalities with age-adjusted odds ratios of 1.81 (95% CI: 1.26, 2.61) and 2.08 (95% CI: 1.41, 3.07) per doubling in concentration, respectively. These associations remained significant after Bonferroni correction, although they did not reach the adjusted significance threshold in certain sensitivity analyses. Furthermore, the doubling in all PFAS included as a mixture was associated with chromosomal abnormalities, indicating an age-adjusted odds ratio of 2.25 (95% CI: 1.34, 3.80), with PFOS as the predominant contributor, followed by PFNA, perfluoroundecanoic acid (PFUnA), and perfluorooctanoic acid (PFOA).

DISCUSSION

The study findings suggested a potential association between maternal exposure to PFAS, particularly PFOS, and chromosomal abnormalities in offspring. However, the results should be interpreted cautiously, because selection bias arising from the recruitment of women in early pregnancy may explain the associations. https://doi.org/10.1289/EHP13617.

Assessing chronic gestational exposure to environmental chemicals in pregnant women: Advancing the co-PBK model

Vulnerable populations, such as pregnant women and their fetuses, confront potential health risks due to exposure to environmental toxic compounds. Computational methods have been popular in assessing chemical exposure to populations, contrasting with traditional cohort studies for human biomonitoring. This study proposes a screening-level approach based on physiologically based kinetic (PBK) modeling to evaluate the steady-state exposure of pregnant women to environmental chemicals throughout pregnancy. To exemplify the modeling application, naphthalene was chosen. Simulation results indicated that maternal fat exhibited significant bioaccumulation potential, with the log-transformed BTF of naphthalene at 0.51 mg kg-1 per mg d-1 in the steady state. The placenta was primarily exposed to 0.83 mg/d naphthalene for a 75.2 kg pregnant woman, considering all exposure routes. In the fetal structure, single-organ fetal PBK modeling estimated a naphthalene exposure of 123.64 mg/d to the entire fetus, while multiple-organ fetal PBK modeling further revealed the bioaccumulation highest in fat tissue. The liver identified as the vital organ for metabolism, kBioT,LiverM was demonstrated with the highest sensitivity among rate constants in the maternal body. Furthermore, the first-order kinetic rate constants related to the placenta and blood were found to impact the distribution process of naphthalene in the fetus, influencing gestational exposure. In conclusion, urgent attention is needed to develop a computational biomonitoring tool for assessing toxic chemical exposure in vulnerable populations.

Association between antinuclear antibody positivity and chemical exposure among pregnant Japanese women: A cross-sectional study based on the Japan environment and Children's study

Antinuclear antibodies (ANAs) are detected in healthy individuals, they are more prevalent in women than in men. Pregnant women are immunologically unique, but epidemiological data on ANA positivity in them remain limited. The exposure received from the mother during the fetal period impacts the future health of the fetus and has thus received increased attention in recent years. Thus, we investigated the association between ANA positivity and chemical exposure among pregnant Japanese women, registered in the Japan Environment and Children's Study (JECS). ANA titers were assessed by indirect immunofluorescence with HEp-2 cells at a cutoff dilution of 1:40. Sociodemographic and other data were obtained in the JECS from a self-administered questionnaire. We analyzed 1,235 Japanese women in their first trimester of pregnancy. The ANA prevalence was 17.2%. Among ANA-positive women, a speckled pattern was the most common (95.3%), followed by a homogeneous pattern (72.3%). Exposure to chemicals more than once a week significantly increased the probability of ANA positivity (kerosene, petroleum, benzene, or gasoline: adjusted odds ratio [AOR], 2.11; 95% confidence interval [95% CI], 1.03-4.34; chlorine bleach or germicide: AOR, 1.97; 95% CI, 1.10-3.54; organic solvents: AOR, 5.34; 95% CI, 1.40-20.36; and photocopying machines or laser printers: AOR, 1.73; 95% CI, 1.17-2.54). ANA positivity was associated with exposure to several chemicals in Japanese women. Our exploratory results suggested that ANAs as potential markers of chemical exposure warrant further research.

embryoTox: Using Graph-Based Signatures to Predict the Teratogenicity of Small Molecules

Teratogenic drugs can lead to extreme fetal malformation and consequently critically influence the fetus's health, yet the teratogenic risks associated with most approved drugs are unknown. Here, we propose a novel predictive tool, embryoTox, which utilizes a graph-based signature representation of the chemical structure of a small molecule to predict and classify molecules likely to be safe during pregnancy. embryoTox was trained and validated using in vitro bioactivity data of over 700 small molecules with characterized teratogenicity effects. Our final model achieved an area under the receiver operating characteristic curve (AUC) of up to 0.96 on 10-fold cross-validation and 0.82 on nonredundant blind tests, outperforming alternative approaches. We believe that our predictive tool will provide a practical resource for optimizing screening libraries to determine effective and safe molecules to use during pregnancy. To provide a simple and integrated platform to rapidly screen for potential safe molecules and their risk factors, we made embryoTox freely available online at https://biosig.lab.uq.edu.au/embryotox/.