Report on chemical exposure is criticised for panicking pregnant women

BMJ 2013; 346 doi: (Published 06 June 2013) Cite this as: BMJ 2013;346:f3695
  1. Jacqui Wise
  1. 1London

A report by the Royal College of Obstetrics and Gynaecology that advises pregnant women to avoid exposure to synthetic chemicals in a range of household products has been criticised for causing unnecessary stress and adding nothing to the debate.1

The scientific impact paper, from the college’s scientific advisory committee, said that pregnant women were exposed to hundreds of such chemicals at a low level and that this exposure could operate additively or interactively.

Although it concluded that on the present evidence it was impossible to assess the risk—if any—from this exposure, it said that women should adopt a “safety first” approach and assume that a risk was present even when it may be minimal or eventually shown to be unfounded.

It said that women should eat fresh rather than processed food whenever possible and to reduce consumption of food in cans and plastic containers, because they may contain chemicals such as bisphenol A and phthalates.

It also said that women should minimise the use of personal care products such as moisturisers, cosmetics, shower gels, and fragrances. It recommended that women avoid buying newly produced household furniture, fabrics, non-stick frying pans, and cars while pregnant or breast feeding.

It also said that women should avoid paint fumes and the use of garden and household pesticides and should take drugs bought over the counter only when necessary. It also pointed out that labelling products as herbal or natural did not necessarily indicate that they were safe for use during pregnancy.

The report said that there was no official advice or guidelines on the potential risks of chemical exposure for pregnant or breastfeeding women and that women were often faced with scare stories about chemicals in the media that were inaccurate or exaggerated. The document’s stated purpose was to raise awareness of the issue of exposure to chemicals and allow women to make an informed decision.

However, the report, which received much media publicity, has been widely criticised for being unhelpful and alarmist. David Spiegelhalter, professor of the public understanding of risk at Cambridge University, said, “These precautionary ‘better safe than sorry’ recommendations are not necessarily cost free. They may feed anxiety and detract attention from the known harms of bad diet, smoking, and excessive alcohol. And it is unclear how any benefits can ever be assessed.”

Tracey Brown, from the charity Sense About Science, said that the public needed help to navigate the debate about chemicals and pregnancy and that the royal college’s new report had ducked this. She said, “As the report itself shows, there are many unfounded rumours about links between particular substances and pregnancy outcomes. By contrast, we have plenty of evidence that stress is a major risk factor in pregnancy. Researchers and professional bodies should not be adding to it.”

The report acknowledged that the epidemiological research linking exposure to chemicals to adverse health effects showed associations and did not imply causality. It also pointed out that levels of exposure to chemicals in animal studies were high, so extrapolation of their results to humans was inappropriate.

The report said that nearly all pregnant women were exposed to certain chemicals because they were found in everyday products. For example, bisphenol A is found in drink and food cans, and phthalate esters are found in plastics, carpets, fabrics, personal care products, and glues, so it was difficult to find an unexposed control group. It said that the current risk assessments for endocrine disrupters such as phthalates indicated that levels of exposure of humans to these chemicals were too low to pose a real risk. However, these assessments were of individual chemicals, and there were no methods to assess risks of exposure to complex mixtures of chemicals.

Andy Smith, from the Medical Research Council’s toxicology unit at the University of Leicester, said, “The exposure of unborn babies during pregnancy or of breastfed babies to possibly harmful chemicals—both synthetic and natural—is of increasing concern, although the real risks are uncertain. Current methods for estimating risk are not yet capable of taking into account very low exposures to mixtures of many chemicals from the environment and the mother’s diet, as well as commercial products.”

Warren Foster, from the department of obstetrics and gynaecology at McMaster University, Ontario, said. “While phthalates are indeed in many commercial products, and thus exposure is widespread, the animal studies conducted to date show that adverse outcomes occur only with very high concentrations that are orders of magnitude above human exposure.

“Consequently, although the data suggest that exposure to these chemicals is common, it is highly unlikely that potential adverse health outcomes will occur. However, altering the diet to include more fresh foods is a more healthy alternative that will reduce exposures to these chemicals, if people remain concerned.”

The Royal College of Midwives’ professional policy adviser, Janet Fyle, said, “Pregnant women must take this [the new report’s] advice with caution and use their common sense and judgment and not be unnecessarily alarmed about using personal care products, such as moisturisers, cosmetics, and shower gels. There needs to be more scientific and evidence based research into the issues and concerns raised by this paper.”


Cite this as: BMJ 2013;346:f3695