A new study by the University of Rochester found that young boys exposed to high levels of phthalates during their mother’s pregnancy may be less likely to play with male-typical toys such as trucks and toy guns.
The study divided pregnant women in their 28th week into four groups by the concentration level of phthalate metabolites in their urine. Once children reached ages 3 to 6, researchers assessed their play behavior by asking parents to describe their favorite type of toys and play. Each child was then given a score reflecting masculine-typical play or feminine-typical play.
Mothers in the highest concentration group were five times more likely to have a boy with a less-masculine score than mothers in the lowest concentration group. The study is published in the International Journal of Andrology.