Compounds found in perfumes, cosmetics, and other chemical products could contribute to infertility in the male offspring of mothers who use them during pregnancy new research suggests.
The study by researchers at Edinburgh University, Scotland provides further evidence that products based on synthetic chemicals such as perfumes and cosmetics are not innocuous fashion accessories or beauty products but are a potential danger to health.
The study led by Professor Richard Sharpe of the Medical Research Council's Human Reproductive Sciences Unit, based in Edinburgh, discovered a period between 8 and 12 weeks of pregnancy was critical to determining future reproductive problems. This is the time in the development of the male foetus when certain hormones are switched on and the reproductive system comes into being.
Professor Sharpe and colleagues say that exposure to certain chemicals during this period is associated with undescended testicles and lower sperm counts in later life. They stressed however that their study was conducted on rats so can not be construed as conclusive proof of the same effects in humans.
It has been widely demonstrated that many of the chemicals found in items such as perfume, cosmetics, household fabrics (e.g. flame retardants) and plastics can disrupt the action of hormones in the body. These chemicals are known as 'endocrine disruptors'. Some of the most common in widespread use are bisphenol A (BPA) and perfluorochemicals (PFCs).
With this in mind the scientists artificially blocked the action of androgens in the rats, which include male sex hormones such as testosterone, for a short period in the womb.
The results clearly showed that if the hormones are blocked, the animals suffered fertility problems. The research also suggested that the potential for other reproductive conditions appearing in later life were also increased, including testicular cancer.
Talking to BBC Scotland's news website Professor Sharpe said: "There are lots of compounds in perfumes that we know in higher concentrations have the potential to have biological effects, so it is just being ultra safe to say that by avoiding using them your baby isn't at risk.
"If you are planning to become pregnant you should change your lifestyle. Those lifestyle things don't necessarily mean that you are going to cause terrible harm to your baby, but by avoiding them you are going to have a positive effect.
"We would recommend you avoid exposure to chemicals that are present in cosmetics, anything that you put on your body that might then get through your body into your developing baby.
"It is not because we have evidence that these chemicals categorically cause harm to babies, it is only based on experimental studies on animals that suggest it is a possibility."
Unfortunately endocrine disrupting chemicals are present in the air and many other products including home furnishings and car interiors i.e. in places where people spend a lot of time. It is therefore a matter of reducing exposure to these chemicals during pregnancy rather than avoiding them completely, which would be impractical.
Professor Sharpe officially unveils his findings this week at the Simpson Symposium in Edinburgh, a gathering of fertility experts organised by Edinburgh University.