Microplastics and Fertility: What We Know and What It Means

Fertility researchers have been monitoring environmental chemical exposure for decades — endocrine-disrupting chemicals including pesticides, PCBs, and phthalates have measurable effects on reproductive hormones and outcomes. Microplastics introduce a new concern: particles that can cross the placenta, accumulate in foetal tissue, and carry a cargo of other chemical pollutants to sites where they would not otherwise reach.

This article covers what is currently known about microplastics and reproduction, what it means practically for people trying to conceive or currently pregnant, and what changes are worth making.

The short answer

Microplastics have been detected in human placentas, amniotic fluid, and breast milk, confirming foetal and infant exposure occurs. A 2024 study found an inverse correlation between microplastic concentration in testicular tissue and sperm count. The additives carried on microplastic surfaces — phthalates, bisphenols, styrenes — are documented endocrine disruptors with effects on oestrogen, testosterone, and thyroid hormones. Causation in humans is not yet proven; association evidence is accumulating. During pregnancy, where the precautionary principle applies most strongly, reducing exposure from synthetic clothing, plastic food contact, and synthetic bedding is practical and low-cost.

What the research has found

Microplastics in the placenta

A landmark 2021 Italian study by Ragusa and colleagues examined six human placentas obtained after normal deliveries. Microplastic particles were detected in all six placentas — on both the foetal-facing side and the maternal-facing side. The particles included polypropylene, polyethylene, and synthetic fibres. The placenta is a highly selective filter; the finding that plastic particles cross it challenged previously held assumptions about barriers to foetal exposure.

Microplastics in amniotic fluid

A follow-up study by the same Italian group in 2022 detected microplastics in amniotic fluid samples from women with uncomplicated pregnancies. This confirmed that foetal exposure is not limited to the placenta — microplastics are present in the fluid environment surrounding the developing foetus.

Microplastics in breast milk

A 2022 Italian study (Ragusa et al.) also detected microplastics in human breast milk samples. All 34 samples tested contained at least one type of microplastic particle. This establishes that infant exposure continues after birth through feeding.

Microplastics and sperm

The 2024 study by Zhao and colleagues (Science of the Total Environment) analysed testicular tissue from 23 men. Microplastics were detected in all samples. Statistical analysis found a significant inverse correlation between total microplastic concentration in testicular tissue and sperm count — men with higher microplastic concentrations tended to have lower sperm counts. Polyethylene was the most commonly detected type. This is an association study; it cannot establish that microplastics caused the lower sperm counts. But it adds to the biological plausibility of the concern.

The chemical cargo problem

Microplastic particles do not travel through the body as clean, inert plastic. In the environment, plastic surfaces adsorb organic pollutants from surrounding water and soil — pesticides, PCBs, flame retardants, and plasticisers including phthalates and bisphenols. When microplastics are absorbed into tissue, they carry this chemical cargo with them.

Phthalates and bisphenols are well-documented endocrine disruptors. Phthalates interfere with testosterone production and have been associated with male reproductive outcomes in epidemiological studies. Bisphenol A (BPA) mimics oestrogen. These are not new concerns — they have been regulated in baby products and food contact materials for years. The microplastic pathway introduces a route for these compounds to reach tissue via a vector that is not captured by current food safety regulations.

Practical steps for reducing exposure during pregnancy and preconception

Clothing and bedding

Synthetic clothing worn against the skin during pregnancy, and synthetic bedding in which you sleep for eight hours, are ongoing sources of dermal contact and airborne synthetic fibre exposure. Switching to natural fibre clothing — particularly for sleepwear, underwear, and bedding — reduces this exposure meaningfully. See the natural fibre clothing collection for wool and cotton options.

Laundry

Every time you wash synthetic clothing, fibres are released into the household water and potentially into indoor air. Using a Guppyfriend bag or laundry drain filter reduces the fibres entering your domestic water system. See How to Reduce Microplastics from Laundry.

Food and water contact

Microplastics from food packaging, bottled water, and plastic food containers are a significant ingestion pathway. Switching to glass and stainless food storage, filtering tap water, and reducing plastic-packaged food reduces ingestion exposure. This is outside the scope of this guide but connects to the broader low-tox approach.

Indoor air

Synthetic textiles in the home — carpets, upholstery, curtains — shed fibres into indoor air continuously, not just during washing. This is a lower-magnitude source than laundering but contributes to background inhalation exposure. Vacuuming with a HEPA filter and prioritising natural fibre soft furnishings over synthetic reduces this.

What is not worth worrying about

Complete elimination of microplastic exposure is not currently possible. Microplastics are in drinking water, the food supply, and outdoor air. The goal of precautionary action is reduction, not perfection. Focus on the highest-volume, highest-frequency exposure sources: frequently washed synthetic clothing, plastic food and water containers, and synthetic bedding in close contact during sleep.

Related guides

• Microplastics in Clothing: The Complete Guide
• Microplastics in the Human Body: What Current Research Shows
• Low-Tox Nursery: What to Prioritise When Setting Up for a Baby
• How to Reduce Microplastics from Laundry: Filters, Bags, and Habits