Girls exposed in the womb to high levels of bisphenol A (BPA), a chemical commonly used in household products, are more likely to suffer behavioural problems.
A study revealed daughters whose mother had recorded higher BPA levels during pregnancy were more likely to be anxious, depressed, aggressive, hyperactive and unable to control their emotions.
There was no such link found among boys, leading researchers to believe that girls hormones make them more sensitive to the effects of BPA.
The research carried out at the Harvard University School of Public Health, compared levels of the chemical in the urine of 244 women three times during their pregnancy and at birth.
Researchers later measured BPA levels in the children each year and at age three, parents completed a survey about their child's behaviour, from which scientists were able to see a link between BPA and toddler behavioural issues.
BPA is used to harden plastics and can be found in bottles as well as knife and fork handles. Known as the gender-bending chemical, previous studies have found that it can interfere with the way hormones are processed in the body.
The EU has banned the chemical's use in baby bottles since June and campaigners are now calling for a Europe-wide ban.