Plastic Particles and Female Fertility: Pathways, Toxicity, and Analytical Challenges

Microplastics (MPs) and nanoplastics (NPs) are widespread environmental contaminants with documented impacts on human health, particularly on the female reproductive system. Defined as polymeric fragments smaller than 5 mm, MPs (typically ranging from 1 µm to 5 mm) and NPs (smaller than 1 µm, often <100 nm) originate either from primary sources—intentionally manufactured for specific industrial applications—or from secondary sources through physical, chemical, or biological degradation of macroplastics. Human exposure occurs via multiple routes, including ingestion, inhalation, dermal absorption, and iatrogenic introduction, with growing evidence that these particles can accumulate in the ovaries, oocytes, and placental tissue. Experimental studies in rodents demonstrate that MPs and NPs induce oxidative stress, trigger inflammatory responses, and promote granulosa cell apoptosis, ultimately diminishing ovarian reserve and impairing folliculogenesis. Clinical and pilot human studies have confirmed the presence of MPs in placentas, umbilical cord blood, and meconium, indicating exposure from the earliest stages of development. Moreover, MPs and NPs may disrupt the hypothalamic–pituitary–ovarian axis, contributing to endocrine dysregulation and hormonal imbalance. Analytical methods such as Fourier-transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy enable detection of these particles in biological samples, although methodological standardization remains insufficient. This paper summarizes current evidence on the exposure pathways, toxicological effects, and reproductive consequences of MPs and NPs in women. It further highlights existing research gaps and evaluates available analytical approaches to support future studies and develop strategies aimed at mitigating their detrimental impact on women’s reproductive health and fertility.