Phthalates, plastics and fertility

Plastics have become part of our day to day. They are convenient, light weight, cheap to produce and can be used for a multitude of purposes. If you look around you, you will notice the number of plastic items in your environment. From food containers, to beauty product bottles, to decorative art around the house. The truth is that plastic is entering our bodies, and healthcare professionals are becoming increasingly aware of the impact of those chemicals in our overall health, and particularly in fertility.

What are phthalates?

Phthalates were developed in the 1920s to make plastics more flexible. They are synthetic chemicals that are added to plastics, and have widespread use in many plastic items like flooring, furniture, toys, shower curtains, pipes, and more. Phthalates stabilize artificial scents and are added to many scented products like perfume, cosmetics, shampoos, lotions, candles, nail polish, and hair spray.

Since phthalates are not chemically bound to the plastics and products in which they are used, they can leach into the environment easily, and then enter our bodies.

Impact of phthalates on fertility

Once in the body, phthalates are endocrine disruptors, which means they bind to hormonal receptors and interfere with the function of reproductive hormones like oestrogen and testosterone. Higher levels of phthalates have been associated with disruption in menstruation, ovulation dysfunction, increased risk of endometriosis, longer times to conception, poor egg quality, poor sperm quality.

Endometriosis

Endometriosis is an oestrogen-dependent disease. The central role of oestrogens in the pathophysiology of endometriosis has led several investigators to postulate a potential relationship between phthalate exposure and endometriosis; however, the results have been ambiguous. Some evidence suggests that endocrine disrupting chemicals may be involved in the development and severity of disease.

Time-to-pregnancy and pregnancy loss

In a cohort study involving 6302 women, increased time to pregnancy after probable occupational exposure to phthalates was observed. Phthalate exposure has also been associated with increased risk of early pregnancy loss.

Pregnancy outcomes

Phthalates may impair early IVF outcomes, specifically egg parameters: fewer total eggs, mature eggs, and fertilized eggs.

Limiting exposure to phthalates

Whilst it’s practically impossible to remove all plastic and phthalates from our lives, we can take some actions to limit exposure:

• Prefer food containers that are plastic-free: phthalates can leak from plastic containers (like water bottles and food containers) exposed to heat and detergent (dishwashers, microwaves). Swap plastic for glass food containers.
• Exchange your phthalate-containing beauty products for safer ones: fragrance free is a good start since fragrance is considered a trade secret and companies do not have to list ingredients that are used for scent in cosmetic products. Choose beauty products that are scented with essential oils.
• Choose phthalate-free nail polish.
• Choose cleaning products and detergents that are fragrance free or scented with essential oils. 
• Avoid synthetic air fresheners and candles.

References

1. https://www.fertstert.org/article/S0015-0282(19)30070-6/fulltext
2. https://www.fertstert.org/article/S0015-0282(17)31471-1/fulltext
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3604737/
4. https://pubmed.ncbi.nlm.nih.gov/7940536/
5. https://pubmed.ncbi.nlm.nih.gov/27424048/
6. https://pubmed.ncbi.nlm.nih.gov/27852689/