Study links synthetic chemicals to infertility

A study of Danish women has found the first evidence that synthetic chemicals widely used in consumer products cause infertility.

In a study to be published on Thursday in the medical journal Human Reproduction, American scientists say that women with higher levels of perfluorinated chemicals (PFCs) in their blood took longer to become pregnant.

Since the 1950s PFCs have been incorporated in everyday items, including food packaging, textiles, upholstery, carpets and personal products. They are under suspicion for damaging human health – and particularly for causing infertility – by disrupting hormones.

But scientists at the University of California, Los Angeles, who carried out the study with the Danish National Birth Cohort, say they are the first to provide statistical evidence PFCs have an effect on people.

Chunyuan Fei of UCLA said: “Recently, animal studies have shown that these chemicals may have a variety of toxic effects on the liver, immune system and developmental and reproductive organs. Very few human studies have been done.”

The UCLA researchers analysed levels of two commonly used PFCs, known as PFOS and PFOA, in the blood of 1,240 Danes during early pregnancy.

These levels were correlated with interviews in which the women were asked whether the pregnancy was planned and how long it had taken them to become pregnant.

The results showed a very strong statistical relationship between PFC levels and time to pregnancy. Women who had large amounts of PFC in their blood were more than twice as likely to have taken more than a year to fall pregnant (or to have needed infertility treatment) than those with low levels.

“This is an important finding and certainly warrants further detailed research, particularly in those trying for a family,” said Tony Rutherford, chair of the British Fertility Society.

UCLA researchers measured PFCs after pregnancy was established, but said levels were unlikely to have changed significantly from before conception. Men’s sperm might also be affected by PFCs – and this damage might contribute to the findings, since most couples would tend to share lifestyles and have similar exposures.