New research has revealed that chemicals found in shampoos used by pregnant women can lead to behavioural problems for their children in later life.

The report, which was published in the Environmental Health Perspectives journal revealed that prenatal exposure to a group of chemicals known as phthalates could increase the risk of mental and psychomotor problems for children when they reach their toddler years.

Women concerned about the findings may be encouraged to switch to herbal shampoo and natural organic beauty products, which are free from harmful additives.

The research was conducted by scientists at Columbia University's Mailman School of Public Health and involved scrutinising the urine samples of a group of 319 women during their third trimester.

Scientists analysed the urine samples for four types of phthalates during pregnancy and subsequently tested each women's child at the age of three using the Bayley Scales of Infant Development II to measure their behavioural, mental and motor development.

The results revealed that a higher exposure to two of the phthalates, which are also found in lotions, cosmetics, flooring and cars, significantly increased the likelihood of the child developing motor delays, while one of the phthalates was found to be associated with considerable delays in mental development among three-year-old girls.

Furthermore, prenatal exposure to three of the phthalates was found to be linked to an increase in behavioural problems in three-year-olds, including anxiety, depression, withdrawn behaviour, somatic complaints and emotionally reactive behaviour.

Phthalates are also common in nail polish, adhesives, hair spray, plastic toys and detergents and are reported to interfere with the endocrine system and have been shown to have an adverse effect on the male reproductive system such as lowering sperm counts and causing testicular atrophy.

Researchers found that the concentrations of the phthalate metabolites measured in the women were 1.3 to 2.7 times higher than in the sample of pregnant women taken in 2003-2004.

Posted by Laura Andrews