Researchers have found a link between drugs used to stimulate the ovaries of women before they undergo treatment for fertility and an increase in the risk of leukaemia in their children.

The initial findings of the new study showed that the use of ovarian stimulation drugs can increase the risk by 2.6 times for children developing the most common form of childhood leukaemia, known as acute lymphoblastic leukaemia (ALL). It found that they had a 2.3 times higher risk of developing acute myeloid leukaemia.

The study also found that children of women who had to wait for than a year to get pregnant and gave birth naturally. The children of these women faced 50% more risk of developing ALL, which indicates that the higher risk might be linked to low fertility among women and not just to the drugs used to stimulate the ovaries of women before they undergo treatment for low fertility.

The researchers said that they did not find any link between fertility procedures and leukaemia. The findings of the study were presented at a conference in London.