Riding the momentum of the Irish referendum and US supreme court ruling legalising same-sex marriage, there are expectations Australian legislators will change the Marriage Act. A cross-party bill to legalise same-sex marriage is expected to be introduced in the Federal Parliament. But passage of the bill is not guaranteed, and many MPs are against the change.

An argument often used against legalising same-sex marriage by groups like the Australian Christian Lobby, and even a group of 40 religious leaders from multiple faiths, is that gay marriage will have a negative impact on children's wellbeing. Opponents of same-sex marriage, including groups like Family Voice Australia claim that studies show a man and a woman are best placed to raise children.

ABC Fact Check took a look at the research on the effects of gender on parenting and found most studies from the US and from Australia saw no difference between families headed by homosexual or heterosexual couples. Read More