TORONTO -- Ontario's governing Liberals are expected to unveil a plan to spend $85 million over three years to expand coverage of in vitro fertilization treatments.

Health Minister Deb Matthews is expected to make the pre-budget announcement today, although the government wouldn't confirm it.

But that's the plan according to leaked budget documents released by the Progressive Conservatives last week.

According to those documents, so-called "fiscal offsets" beyond one round of treatment will be determined if needed.

The Liberals made an election promise in 2007 to make fertility monitoring available earlier in life and make treatment "more accessible and affordable."

But the government has maintained that it didn't promise to fund in vitro fertilization treatments.

Advocates for couples struggling with infertility say it can cost tens of thousands of dollars for drugs and treatment.

They say many infertile families turn to less effective and more dangerous alternatives to try to get pregnant, which can significantly increase the risk of multiple, pre-term births and severe medical and developmental problems.

Experts who have studied the issue found that public funding of IVF will improve the health of mothers and babies as well as reduce health-care costs, they say.

The government could establish stringent rules, such as limiting the number of embryos transferred, which could reduce the chances of multiple births.

Quebec became the first jurisdiction in North America to pay for fertility treatments in 2010. Manitoba offers a tax credit to cover part of the costs to a maximum of $8,000 a year.