IVF patients are a third more likely to develop ovarian cancer, a landmark UK study suggests.
Doctors say the extra risk shows the need for women to be screened for the disease following fertility treatment.
Scientists analysed the records of all the 255,000 Britons who have had IVF over the past two decades.
Initial results revealed yesterday show those who have had help to conceive are 37 per cent more likely than other women to develop ovarian cancer.
The study’s authors say the most probable explanation is that the underlying problems making women infertile also put them at greater risk of cancer.
But they admit there is a small possibility that the treatment itself is to blame. Women were in most danger from ovarian cancer in the three years after starting IVF.
This, along with the fact that the risk was greater among younger women, supports the theory that the treatment itself is linked to disease. Previous research has suggested that IVF drugs may promote cancer growth.
This suggests the danger comes from stimulating the ovaries to produce multiple eggs instead of just one.
Even if this were true though the chance of getting cancer is still very low.
Repromed clinical director Professor Kelton Tremellen said “the bulk of the evidence to date does not support a link between the use of IVF stimulation drugs and ovarian cancer”.
“Even if we accept this UK report to be true, the absolute increase in risk for an individual women is extremely small,” he said.
“If women have had IVF in the past and have concerns that they may be at increased risk of ovarian cancer then they should see there local GP or fertility specialist for assessment.”
Royal Adelaide Hospital Professor Martin Oehler, director of the hospital’s Department of Gynaecological Oncology, said the study revealed ovarian cancer numbers in women who had undergone IVF were low.
“Women really shouldn’t panic about this data,” he said.
“However it is interesting to see there is a link.”
Alastair Sutcliffe, the professor in charge of the University College London study, said he was convinced IVF itself was not at fault.
“This internationally-unique study suggests little for women to worry about regarding the risk of cancers and the drug treatments they undergo to have a baby with IVF,’’ he said.
Dr Stuart Lavery, of Imperial College London, said the study suggests that for women already prone to cancer because of their infertility, IVF treatment may increase that risk.
“Patients are very interested in the long-term impact fertility treatment has,’’ he added.
“Every single woman who comes through our doors wants to know what the long-term consequences will be.’’
The take-up of IVF has hugely increased as more Britons put off starting a family until it is too late to conceive naturally. Around 50,000 have the procedure each year.
The study looked only at the statistical chance of developing ovarian cancer – and did not examine the possible reasons behind this. Only 15 women out of every 10,000 who had IVF developed the disease during the research period. The rate among all other women was little different: 11 in 10,000.