Phthalates may affect fertility in women, according to study
A new study led by researchers from Massachusetts General Hospital and Harvard Medical School in Boston, USA, suggests that phthalates, chemicals found in plastics and cosmetics, may be a cause of low fertility in women undergoing in vitro fertilization. Phthalates effects on fertility have been highlighted by several studies in the past as these compounds have been identified as potential environmental factors of infertility; this is why they are called “endocrine disruptors”.
Phthalates are esters of phthalic acid and are found in a wide range of products: plastics, pharmaceuticals, paints, textiles, detergents, etc.. There are two types of phthalates: phthalates are used to manufacture plastic products (high molecular weight phthalates) and phthalates that are used to manufacture cosmetics (low molecular weight phthalates). Although there have been many studies that have shown the effects of phthalates on male fertility (it looks like it drops the quality and quantity of semen), there is very little information on low-level, daily exposures to phthalates on the female reproductive system.
Dr. Souter, from Massachusetts General Hospital and Harvard Medical School in Boston, USA, believes that exposure to phthalates can lead to specific adverse effects on female reproductive system. To verify this hypothesis, the researchers conducted a study on 231 women undergoing IVF at the Massachusetts General Hospital between 2004 and 2012. The researchers wanted to identify the effects of exposure to phthalates, therefore they took urine samples at the beginning and end of treatment to identify metabolites derived from phthalates.
To assess the relationship between the levels of urinary metabolites and the effects on female reproductive system, researchers analyzed three markers of response to IVF: the number of eggs produced after hormonal treatment for IVF, embryo development and implantation failure. The results showed that exposure to phthalates was widespread as urinary metabolites were detected in almost all the women who took part in the study. Results showed that implantation failure rate was directly proportional to the level of urinary phthalate metabolites. It was also found that the number of oocytes retrieved was lower as the level of urinary phthalate metabolites was higher. However, the researchers found no association between urinary levels of phthalates and rates of fertilization or embryo development.
Dr Souter believes that these results confirm the hypothesis that phthalates are widespread in the environment and can have adverse effects on female fertility. “We are all primarily exposed to phthalates through inhalation and ingestion. “It is extremely difficult if not impossible to avoid exposure to phthalates, since they are in so many products”, Dr. Souter said.