Phthalates and Fertility: What You Need to Know 

Phthalates are chemicals used widely in plastics, cosmetics, and many everyday products. Over recent years, a growing body of research has raised concerns about how these substances may affect fertility.  

In this article, we’ll help you understand their potential impact on fertility so you can make informed choices on your path to parenthood. 

What Are Phthalates? 

Phthalates are industrial chemicals added to plastics to make them more flexible and durable.

They are also found in fragranced personal care items, medical tubing, household products, and even food packaging.  

Because they are not tightly bound to the materials they’re added to, phthalates can leach into food, water, and the air, creating widespread exposure in humans.

Phthalates belong to a group of endocrine-disrupting chemicals (EDCs). These compounds interfere with hormonal systems.

Hormones play a central role in reproduction, which makes phthalates of particular concern when it comes to fertility.

How Phthalates Affect Female Fertility 

Research shows that phthalates may impact several aspects of ovarian and uterine health: 

• Ovarian disruption: Studies show that phthalates can increase oxidative stress in ovarian tissue, disrupt follicle growth, and even lead to follicle death, all of which can compromise fertility.

• Impaired egg development: Phthalates can interfere with the normal cycle of egg growth in the ovaries. Normally, the body carefully regulates how eggs develop and mature, but phthalates may speed up the process of “recruiting” eggs before they’re ready, prevent eggs from fully maturing, and even block ovulation (the release of an egg). They can also cause eggs or follicles (the small sacs that contain the eggs) to break down and die off earlier than they should.

• Pregnancy outcomes: Some studies in humans suggest that higher phthalate exposure may make it take longer to get pregnant and could increase the risk of early pregnancy loss.

How Phthalates Affect Male Fertility 

Men are also at risk of phthalates impacting their fertility. Several studies link phthalate exposure to reduced sperm quality and hormonal disruption: 

• Sperm function: For fertilization to occur, sperm must undergo processes called capacitation and the acrosome reaction. These prepare the sperm to penetrate the egg’s outer layer. Animal studies show that phthalates can impair these steps, which could reduce the chances of successful fertilization.

• Sperm quality: Human studies have found associations between phthalate exposure and reduced sperm motility (movement), abnormal morphology (shape), and lower sperm counts. These changes affect how efficiently sperm can reach and fertilize an egg.

• DNA integrity: Some evidence suggests that phthalates increase oxidative stress in sperm, leading to DNA fragmentation. Damaged DNA can compromise embryo development, even if fertilization occurs.

In short, phthalates may reduce both the quality and function of sperm, potentially lowering fertility and affecting pregnancy outcomes. 

The Research on Phthalates and IVF

Emerging research shows that exposure to phthalates can directly reduce the chances of success in in vitro fertilization (IVF) in the following ways. 

Reduced Pregnancy Chances

A 2021 study found that women with higher levels of mono-n-butyl phthalate (MBP) in their urine had a 68% lower likelihood of achieving pregnancy during IVF. In other words, even small increases in exposure to this type of phthalate significantly reduced the chances of becoming pregnant.

Lower Odds of Live Birth

Higher levels of another phthalate metabolite called mono-(2-ethyl-5-hydroxyhexyl) phthalate (MHxP), were linked to a 92% lower chance of live birth. This shows that phthalates don’t just affect early conception, but also the ability to carry a pregnancy to a successful outcome.  

Increased Risk of IVF Failure

A 2025 systematic review and meta-analysis found that exposure to DEHP metabolites (such as MEHP) is associated with : 

• 35% higher risk of biochemical pregnancy loss (very early miscarriage) 

• 56% higher risk of failed clinical pregnancy 

• 54% higher risk of live birth failure  

Additionally, a 2024 systematic review found that exposure to phthalates may negatively influence ART outcomes, though the evidence is not yet fully consistent.

An umbrella review drawing from hundreds of studies further concluded that plastic-related chemicals, including phthalates, are associated with infertility and spontaneous pregnancy loss.

What This Means for IVF Patients 

Put simply, phthalates can make it harder to get pregnant, increase the risk of early miscarriage, and reduce the likelihood of delivering a healthy baby through IVF.  

5 Practical Ways to Reduce Phthalates Exposure 

It is impossible to eliminate phthalates entirely, but small lifestyle changes can significantly reduce exposure: 

1. Choose whole foods over processed foods to minimize contact with plastic packaging. 

1. Store and heat food in glass, ceramic, or stainless steel rather than plastic containers. 

1. Select fragrance-free or phthalate-free cosmetics and personal care products, since phthalates are often hidden under the term “fragrance.” 

1. Avoid plastics labeled #3, #6, and #7, which are more likely to contain harmful additives. 

1. Replace products, starting with those you use daily, such as water bottles, food containers, and skincare items. 

Phthalates and Fertility: The Takeaway 

The science on phthalates and fertility is growing, and the evidence so far suggests that these chemicals can interfere with reproductive health in both women and men.  

From ovarian disruption and altered sperm function to potential effects on IVF outcomes, phthalates are an environmental factor that can have serious negative effects on fertility. 

While exposure is difficult to avoid completely, being mindful about food storage, product choices, and personal care items can help reduce risk and support reproductive health.