Kyriaki Mitta
MD, MSc, PHD(c), Gynecologist in Assisted Reproduction
Scientists call them microplastics (smaller than a grain of rice) and nanoplastics (invisible to the eye). These particles are everywhere around us. They are found in the air we breathe, the water we drink, the food we eat, and even in household dust and come from the breakdown of larger plastic waste, synthetic clothing fibers, personal care products, packaging, and medical supplies. Because plastic is so widely used and slow to degrade, these particles have spread into every part of our environment and unfortunately, into our bodies too [1,2].
Researchers have now detected microplastics in human blood, lungs, placenta, and even in semen, ovaries and breast milk. This means that plastic particles can cross important body barriers and reach organs that are vital for reproduction. Although research is still developing, growing evidence suggests that these particles can harm fertility in both women and men and may also affect unborn babies [2,3].
For men, studies have shown that microplastics can build up in the testes and semen, reducing sperm number, movement, and quality. Animal studies have found that these particles can damage the structure of the testicles and disrupt hormone balance by causing inflammation and oxidative stress [1,2]. Researchers in China found microplastics in every semen sample they studied, with clear links between higher exposure and poorer sperm health [4].
For women, microplastics have been found in ovarian tissue, uterus, follicular fluid (the fluid around eggs), and the placenta. These particles may cause inflammation, hormonal imbalance, and changes in the cells that help eggs mature and the uterus stay healthy [5,6,7]. Some studies linked microplastics in the placenta with smaller birth weights and lower Apgar scores in newborns, suggesting possible effects on fetal development. Animal research shows that when mothers are exposed to microplastics, the particles can cross the placenta, reaching the developing baby and leading to developmental and metabolic problems later in life [8,9].
These findings are worrying because infertility is already a growing global problem, affecting about one in six couples. If environmental pollution, especially from plastics, contributes to this trend, we need urgent action. However, many people, including healthcare professionals, are still unaware of this hidden risk.
That is why awareness and education are essential. The public should know simple ways to reduce exposure, like choosing glass or stainless steel containers, avoiding heating food in plastic, cutting down on bottled water, and supporting recycling initiatives. Healthcare workers also need to be informed so they can educate patients, especially those planning pregnancy, and encourage research and policies to monitor and limit microplastic exposure.
Although scientists are still learning exactly how microplastics affect fertility and pregnancy, what is already known is enough to call for caution. Reducing plastic pollution and understanding its effects on our bodies are important steps to protect not only the environment but also the health of future generations.
References
1. Hong Y, Wu S, Wei G. Adverse effects of microplastics and nanoplastics on the reproductive system: A comprehensive review of fertility and potential harmful interactions. Sci Total Environ. 2023;903:166258.
2. Doroftei B, Savuca A, Cretu AM, et al. Microplastics and human fertility: A comprehensive review of their presence in human samples and reproductive implication. Ecotoxicol Environ Saf. 2025;303:118939.
3. Hunt K, Davies A, Fraser A, et al. Exposure to microplastics and human reproductive outcomes:A systematic review. BJOG. 2024;131(5):675–683.
4. Zhang C, Zhang G, Sun K, et al. Association of mixed exposure to microplastics with sperm dysfunction: a multi-site study in China. EBioMedicine. 2024;108:105369.
5. Geng Y, Liu Z, Hu R, et al. Toxicity of microplastics and nanoplastics: invisible killers of female fertility and offspring health. Front Physiol. 2023;14:1254886.
6. Qin X, Cao M, Peng T, et al. Features, Potential Invasion Pathways, and Reproductive Health Risks of Microplastics Detected in Human Uterus. Environ Sci Technol. 2024;58(24):10482–10493.
7. Montano L, Raimondo S, Piscopo M, et al. First evidence of microplastics in human ovarian follicular fluid: An emerging threat to female fertility. Ecotoxicol Environ Saf. 2025;291:117868.
8. Tian J, Liang L, Li Q, Li N, Zhu X, Zhang L. Association between microplastics in human amniotic fluid and pregnancy outcomes. J Hazard Mater. 2025;482:136637.
9. He Y, Yin R. The reproductive and transgenerational toxicity of microplastics and nanoplastics: A threat to mammalian fertility in both sexes. J Appl Toxicol. 2024;44(1):66–85.
