An American study has found that fathers' exposure to phthalates could affect their chances of reproductive success. Studying 50 couples undergoing in vitro fertilization (IVF), the scientists found that fathers showing signs of phthalate exposure were less likely to have high-quality embryos.

Researchers at the University of Massachusetts, USA, studied the impact of fathers' exposure to phthalates on reproductive success. Phthalates are endocrine-disrupting compounds found in certain plastics, foods and personal care products.

The scientists tested for the presence of phthalates in the urine of men undergoing IVF on the same day as they collected sperm and oocytes (egg cells that are fertilized to become embryos) for the procedure.

Of the 761 oocytes collected, 423 progressed to the cleavage stage (day three), 261 were high-quality cleavage stage embryos, 137 were transferable quality blastocysts, and only 47 were high-quality blastocysts, a stage of embryonic development at around five to seven days.

Based on their results, the scientists found that exposure to phthalates was associated with "a pronounced decrease in blastocyst quality."

The study suggests that environmental factors can affect reproductive success. Further research is now required to study the behavior of these "damaged" embryos and investigate the mechanisms by which phthalates affect their quality.

Produced in large quantities in the plastics industry, phthalates are used to manufacture everyday products such as adhesives, vinyl floor coverings, detergents, pharmaceuticals, electrical cables and lubricant oils.

A 2012 report from France's national institute of health and medical research (Inserm) previously found that phthalates reduced testosterone production by 30 per cent, in turn reducing fertility.