Early life in the Plasticene: short- and long-term effects of perinatal exposure to microplastics and plastic-associated chemicals – PART I

Over the last decades, the rapid expansion of plastic production, combined with poor circularity, inadequate waste management, and the long-term persistence of synthetic polymers, has led to widespread environmental contamination. Plastics are now so pervasive that they have been proposed as a defining feature of the so-called Plasticene. The perinatal period represents a critical window of susceptibility, during which environmental ex posures can shape developmental processes and influence long-term health trajectories. The aim of this two-part narrative review is to explore the sources and health implications of plastic exposure during the prenatal (Part I) and early neonatal (Part II) periods, with a focus on microplastics and plastic-associated chemicals as complex and cumulative components of the early-life exposome. Current evidence indicates that exposure to microplastics and plastic-associated chemicals can begin before birth, with maternal exposure occurring through multiple routes. Microplastics have been found in the placenta, amniotic fluid and cord blood, supporting biological access to the fetoplacental unit and the possibility of transplacental passage. Available human studies have explored potential associations between prenatal micro plastic exposure and adverse pregnancy and fetal outcomes, including impaired growth and altered cord-blood endocrine profiles, but the evidence is preliminary and limited by predominantly cross-sectional designs and substantial heterogeneity in analytical methods, such as differences in particle-size detection thresholds and polymers assessed. Evidence for plastic-associated chemicals, particularly phthalates, is more extensive and suggests associations with preterm birth, endocrinological alterations, and neurodevelopmental outcomes, although residual confounding, exposure misclassification, and co-exposure to complex chemical mixtures remain important limitations. Further prospective studies using repeated measurements, rigorous contamination- control procedures, and long-term follow-up are needed to better characterize these associations and their po tential consequences for offspring health. The ubiquitous nature of plastic exposure, coupled with the growing body of evidence on its potential con sequences, warrants urgent action. Effectively tackling the perinatal plastic exposome requires coordinated multidisciplinary efforts within a One Health framework, integrating environmental, clinical, and regulatory strategies to reduce exposure and protect early-life health.