Recent research showed that exposure of women to hairspray during pregnancy doubles the chances of the genital defect in the boys at the time of birth.

The study focused on frequency and the amount of exposure to the hair spray during pregnancy. Researchers from Imperial College London interviewed a total of 471 women whose babies had been born with hypospadias and a similar number of women with unaffected children.

During the study, nearly double the number of women in the "hypospadias" group revealed that they had been exposed to hairspray through their job compared with those with unaffected babies.

Lead researcher, Professor Paul Elliott said that the finding did not prove that hairspray - or any phthalates it contained - was the cause of this.

He added: "Women shouldn't be alarmed. This study adds a bit more evidence to the general picture about these chemicals, but more research will be needed to demonstrate that the link exists."

Prof. Elliott further said: "Pregnant women will need to make their own choices about whether or not to avoid these kind of exposures."