Tiny pieces of debris from plastic have been found to be present in over two-thirds of follicular fluids and in more than half of semen fluids, according to a study of 51 fertility patients (1).
The data presented at ESHRE and published simultaneously in Human Reproduction was described as ‘promising’ by lead author Emilio Gomez-Sanchez. However, Dr Gomez-Sanchez, from the University of Murcia, stressed the findings were not a cause for alarm, and should be interpreted with caution because of the small sample size.
Moreover, the analysis did not report fertility outcomes so it is unknown if the presence of microplastics may impact reproductive health.
Defined as particles measuring 5mm and below, microplastics are already known to be present in human organs. Many papers, on both animals and humans, have been published in the last couple of years suggesting a link between microplastics and reproduction. Recent human studies have linked the presence of microplastics in ovaries to lower fertilisation rates (2), poorer sperm quality in semen, and possible reduced cell viability in placenta.
The majority of those found in this new study were polytetrafluoroethylene (PTFE), a polymer used in non-stick cooking equipment, textiles and many other products used daily by people.
The aim of the research was to detect and characterise microplastics in follicular fluid from women undergoing ovarian stimulation and follicular puncture, and to assess the presence and composition of microplastics in semen from patients undergoing fertility evaluation. between March 2024 and February 2025
Researchers recruited 29 women and 22 men from whom they collected samples which were then frozen in glass containers. Chemicals were used to break down the samples to make them easier to analyse. Dr Gomez-Sanchez and his team then used laser direct infrared imaging to detect the presence of microplastic particles.
Findings showed microplastics present in 69% of the follicular fluid samples analysed. PTFE was found in 31% of the samples followed by polypropylene (PP) (28%), polyethylene terephthalate (PET) (17%), polyamide (PA) (14%), polyethylene (10%), polyurethane (PU) (10%), and polystyrene (PS) (7%). In male seminal fluid samples, microplastics were present in 55% of those analysed. PTFE again emerged as the most prevalent polymer, identified in 41% of the samples. Other polymers detected included PS (14%), PET (9%), PA (5%), and PU (5%), though in lower concentrations.
Dr Gomez-Sanchez said it remains to be seen whether the microplastics detected in semen come from the seminal glans, the epididymis or the testicles. Enhanced vascularisation during ovarian stimulation could explain, he said, the higher concentration of microplastics found in the ovary (compared to semen).
Despite the small sample size, the study demonstrates just how commonly microplastics enter reproductive fluids and the need to explore possible implications for human reproductive health.
In his presentation, Dr Gomez-Sanchez said that additional studies with larger cohorts are now needed to validate preliminary observations, assess the potential associations between patient parameters and microplastics, and determine if microplastics influence reproductive health.
On this basis, the research team plans to expand their analysis to a larger cohort, alongside detailed lifestyle and environmental exposure questionnaires. Further phases of the project will also explore the potential relationship between the presence of microplastics and oocyte and sperm quality.
In a question-and-answer session, Dr Gomez-Sanchez said that it was unclear which patients may be more at risk of having higher amounts of microplastics in reproductive fluids. The effect of accumulation may make it easier to find plastic in older women, he suggested, but the picture is less clear in oocyte donors etc.
Dr Gomez-Sanchez was also asked if the plastic equipment used to extract follicular fluid accounted for the higher amount of microplastics in women. This was a concern for the research team, he said. As such, they were careful to use water blanks to rule out any potential contamination.
Microplastics are just one of many elements that play a role in fertility, according to Dr Gomez-Sanchez. But simple steps can minimise exposure such as reducing the amount of water consumed from plastic bottles.
References:
1 Gomez-Sanchez E, Peñalver-Soler R M, Almunia N, Pérez-Álvarez M C, Luque M D et al. O-280 Unveiling the hidden danger: detection and characterisation of microplastics in human follicular and seminal fluids. Hum Reprod Vol 40, Issue Supplement_1, June 2025, deaf097.280; https://doi.org/10.1093/humrep/deaf097.280
2 Wang W, Chi F, Liu Y, Chang Q, Chen S et al. Polyethylene microplastic exposure adversely affects oocyte quality in human and mouse. Environment International Volume 195, 2025, 109236, ISSN 0160-4120; https://doi.org/10.1016/j.envint.2024.109236.
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