Microplastics (MPs) have become a pervasive environmental contaminant, with increasing evidence of their accumulation in human tissues (Li et al., 2024). A recent study by Montano et al. (2025) provides the first direct evidence of MPs in human ovarian follicular fluid, revealing potential risks to female reproductive health. The study detected microplastics in 14 out of 18 follicular fluid samples, with a significant correlation between MP concentration and follicle-stimulating hormone (FSH) levels.
This discovery raises concerns about the impact of MPs on ovarian function, fertility, and overall reproductive health. By employing a patented extraction and detection methodology, the study establishes a new standard for MP research in human tissues. Given the relentless rise in plastic production and its potential consequences on reproductive health (UNEP, 2021), these findings underscore the urgent need for further research and regulatory measures to mitigate the risks posed by MPs.
1. First evidence of microplastics in human ovarian follicular fluid
The Italian study by Montano et al. (2025) represents a significant breakthrough in reproductive and environmental health by providing the first-ever evidence that microplastics are present in human ovarian follicular fluid. Prior research on MPs in reproductive tissues was limited to animal models (Wang et al., 2023), making this discovery a crucial step in understanding human exposure. The study analyzed follicular fluid samples from 18 women undergoing assisted reproductive treatments and found MPs in 14 of them. The identified MPs were smaller than 10 micrometers, with an average concentration of 2,191 particles per milliliter and a mean diameter of 4.48 micrometers.
The presence of MPs in this biological environment, which plays a critical role in oocyte maturation (Gosden et al., 1988), raises serious concerns about their potential to interfere with female reproductive function. Given that follicular fluid provides essential nutrients and biochemical signals for developing oocytes, the contamination of this medium may have implications for fertility, hormonal balance, and overall ovarian health.
2. A technological breakthrough in MP detection
The study’s findings were made possible by an advanced patented methodology specifically designed for the extraction and quantification of microplastics in biological fluids. This technique represents a significant improvement over conventional filtration-based methods, which often fail to recover smaller MPs, leading to underestimation of contamination levels (Montano et al., 2023). The methodology demonstrated a high recovery rate of 83–103% for 3-micrometer polystyrene particles and a detection limit as low as 0.1 micrometers, allowing researchers to identify even nanoplastics.
To ensure accuracy, the study employed scanning electron microscopy (SEM) combined with energy-dispersive X-ray (EDX) spectroscopy, enabling high-resolution imaging and precise chemical composition analysis. Rigorous contamination control measures were also implemented, including the exclusive use of glassware, dust-free gloves, and a cleanroom environment. This meticulous approach ensures the reliability of the results and sets a new standard for future research on MPs in human tissues.
3. Correlation between MPs and ovarian dysfunction
One of the study’s most significant findings was the observed correlation between MP concentration in follicular fluid and elevated follicle-stimulating hormone (FSH) levels. Higher MP presence was associated with increased FSH, a hormone that regulates ovarian function and is commonly used as a biomarker for ovarian reserve (Petro et al., 2012). Elevated FSH levels are typically indicative of diminished ovarian reserve, suggesting that MPs may contribute to premature ovarian aging and impaired fertility.
Although weaker associations were noted with other factors such as body mass index (BMI), age, and estradiol levels, the significant correlation with FSH points to a possible role of MPs in disrupting ovarian function. This finding aligns with previous research on environmental pollutants affecting female fertility (Oliveri Conti et al., 2020) and raises concerns about how MP accumulation in reproductive tissues might influence hormonal regulation and ovarian aging.
4. Mechanisms of teproductive toxicity
The reproductive toxicity of MPs is an emerging concern, with previous animal studies highlighting several potential mechanisms through which they may impair ovarian function. Research has shown that MPs, particularly polystyrene microplastics, can induce oxidative stress in ovarian tissues, triggering granulosa cell apoptosis and fibrosis (An et al., 2021). These processes can compromise follicular development and overall ovarian health.
MPs have also been found to interfere with key ovarian regulatory pathways, such as the Wnt/β-catenin pathway, which plays a role in fibrosis (Li et al., 2022), and the PERK-eIF2α-ATF4-CHOP pathway, associated with oxidative and endoplasmic reticulum stress (Wang et al., 2023).
Furthermore, MPs act as carriers for endocrine-disrupting chemicals (EDCs) like bisphenols, phthalates, and polycyclic aromatic hydrocarbons, amplifying their toxic effects (Ullah et al., 2023). This ‘Trojan hors’ effect suggests that MPs could not only accumulate in reproductive tissues but also introduce additional harmful compounds, further exacerbating their impact on fertility (Schell et al., 2022).
5. Implications for female fertility
The discovery of MPs in follicular fluid raises serious concerns about their impact on female fertility. Oocyte quality is crucial for successful fertilization and embryo development, and any disruption in the follicular environment could compromise reproductive outcomes (Ferrante et al., 2022). The presence of MPs in follicular fluid suggests that they might interfere with oocyte maturation, reducing fertilization potential and embryo viability.
Additionally, the correlation between MPs and elevated FSH levels indicates that MP exposure could contribute to hormonal imbalances, potentially accelerating ovarian aging. Given that the human body cannot efficiently eliminate MPs, their accumulation over time may have long-term consequences for reproductive health. Chronic exposure to MPs could lead to cumulative damage, increasing the risk of infertility and damage to other reproductive disorders (Pironti et al., 2021).
6. Interim conclusions: a call for urgent action
This landmark study provides compelling evidence that MPs have infiltrated the human reproductive system, with potentially serious consequences for female fertility. The detection of microplastics in ovarian follicular fluid confirms their ability to accumulate in reproductive tissues, raising concerns about their long-term effects. The observed correlation between MPs and FSH levels suggests that MP exposure may disrupt ovarian function and contribute to premature ovarian aging.
Beyond its findings, the study’s patented methodology establishes a new benchmark for MP detection in human biological samples, paving the way for future research. The mechanisms of reproductive toxicity identified in animal models, including oxidative stress, apoptosis (i.e., cellular death) and endocrine disruption, appear to be relevant in human tissues as well. Given that follicular fluid plays a crucial role in oocyte development, MP contamination could significantly impact fertility, emphasizing the need for further investigations into their long-term effects.
7. Public health and policy implications
The presence of MPs in human reproductive tissues is a pressing public health issue that demands immediate attention. Stricter regulations on plastic production and waste management are necessary to reduce environmental contamination and minimize human exposure (UNEP, 2021). Public awareness campaigns should be launched to educate individuals on ways to limit MP exposure, particularly through food packaging, cosmetics, and household products (Ferrante et al., 2022).
Further research is also essential to determine the full extent of MP-related reproductive toxicity. Larger studies are needed to assess the long-term effects of MP accumulation in the female reproductive system and to standardize methodologies for MP detection. Additionally, international collaboration is crucial to address plastic pollution as a global health concern, requiring coordinated efforts from governments, industries, and the scientific community.
Dario Dongo
References
1. Li Y. et al. (2024). Microplastics in the human body: A comprehensive review of exposure, distribution, migration mechanisms, and toxicity. Science of the Total Environment 946:174215 https://doi.org/10.1016/j.scitotenv.2024.17421
2. Montano, L., Raimondo, S., Piscopo, M., Ricciardi, M., Guglielmino, A., Chamayou, S., Gentile, R., Gentile, M., Rapisarda, P., Oliveri Conti, G., Ferrante, M., and Motta, O. (2025). First evidence of microplastics in human ovarian follicular fluid: An emerging threat to female fertility. Ecotoxicology and Environmental Safety, 291, 117868. https://doi.org/10.1016/j.ecoenv.2025.117868
3. An, R., Wang, X., Yang, L., Zhang, J., Wang, N., Xu, F., Hou, Y., Zhang, H., and Zhang, L. (2021). Polystyrene microplastics cause granulosa cell apoptosis and fibrosis in ovary through oxidative stress in rats. Toxicology, 449, 152665. https://doi.org/10.1016/j.tox.2020.152665
4. Ferrante, M., Pietro, Z., Allegui, C., Maria, F., Antonio, C., Pulvirenti, E., Favara, C., Chiara, C., Grasso, A., Omayma, M., Gea, O.C., and Banni, M. (2022). Microplastics in fillets of Mediterranean seafood: A risk assessment study. Environmental Research, 204, 112247. https://doi.org/10.1016/j.envres.2021.112247
5. Gosden, R.G., Hunter, R.H., Telfer, E., Torrance, C., and Brown, N. (1988). Physiological factors underlying the formation of ovarian follicular fluid. Journal of Reproduction and Fertility, 82, 813–835. https://doi.org/10.1530/jrf.0.0820813
6. Leslie, H.A., van Velzen, M.J.M., Brandsma, S.H., Vethaak, A.D., Garcia-Vallejo, J.J., and Lamoree, M.H. (2022). Discovery and quantification of plastic particle pollution in human blood. Environment International, 163, 107199. https://doi.org/10.1016/j.envint.2022.107199
7. Li, X., Zhang, T., Lv, W., Wang, H., Chen, H., Xu, Q., Cai, H., and Dai, J. (2022). Intratracheal administration of polystyrene microplastics induces pulmonary fibrosis by activating oxidative stress and Wnt/β-catenin signaling pathway in mice. Ecotoxicology and Environmental Safety, 232, 113238. https://doi.org/10.1016/j.ecoenv.2022.113238
8. Montano, L., Giorgini, E., Notarstefano, V., Notari, T., Ricciardi, M., Piscopo, M., and Motta, O. (2023). Raman Microspectroscopy evidence of microplastics in human semen. Science of the Total Environment, 901, 165922. https://doi.org/10.1016/j.scitotenv.2023.165922
9. Oliveri Conti, G., Ferrante, M., Banni, M., Favara, C., Nicolosi, I., Cristaldi, A., Fiore, M., and Zuccarello, P. (2020). Micro- and nano-plastics in edible fruit and vegetables. The first diet risks assessment for the general population. Environmental Research, 187, 109677. https://doi.org/10.1016/j.envres.2020.109677
10. Petro, E.M.L., Leroy, J.L.M.R., Covaci, A., Fransen, E., De Neubourg, D., Dirtu, A.C., De Pauw, I., and Bols, P.E.J. (2012). Endocrine-disrupting chemicals in human follicular fluid impair in vitro oocyte developmental competence. Human Reproduction, 27, 1025–1033. https://doi.org/10.1093/humrep/der448
11. Pironti, C., Ricciardi, M., Motta, O., Miele, Y., Proto, A., and Montano, L. (2021). Microplastics in the Environment: Intake through the Food Web, Human Exposure and Toxicological Effects. Toxics, 9, 224. https://doi.org/10.3390/toxics9090224
12. Schell, T., Rico, A., Cherta, L., Nozal, L., Dafouz, R., Giacchini, R., and Vighi, M. (2022). Influence of microplastics on the bioconcentration of organic contaminants in fish: Is the “Trojan horse” effect a matter of concern? Environmental Pollution, 306, 119473. https://doi.org/10.1016/j.envpol.2022.119473
13. Ullah, S., Ahmad, S., Guo, X., Ullah, S., Nabi, G., and Wanghe, K. (2023). A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals. Frontiers in Endocrinology, 13. https://doi.org/10.3389/fendo.2022.1084236
14. UNEP (2021). Drowning in Plastics – Marine Litter and Plastic Waste Vital Graphics. United Nations Environment Programme. https://tinyurl.com/2dakwm7u
15. Wang, W., Guan, J., Feng, Y., Liu, S., Zhao, Y., Xu, Y., Xu, H., and Fu, F. (2023). Polystyrene Microplastics Induced Ovarian Toxicity in Juvenile Rats Associated with Oxidative Stress and Activation of the PERK-eIF2α-ATF4-CHOP Signaling Pathway. Toxics, 11, 225. https://doi.org/10.3390/toxics11030225
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
 in human ovarian follicular fluid, posing risks to female reproductive health.){kind=link}