A new law is being considered in New South Wales which could change the state of reproductive rights based largely on outcry from a recent event.

The proposed 'Zoe’s Law' is intended to specify a foetus as a separate living being from its mother after 20 weeks or when it is heavier than 400 grams. Supporters say the law will create a clear definition for crimes against unborn children; opponents say it only confuses already vague legislation.

Moves to enact the new laws stem from events in 2010, when an unborn child was killed but her mother survived after a car crash with a drug-affected driver. The bill has been carried along by long-term anti-abortion activists, though proponents claim it will not affect the current ruling on women’s rights to terminate pregnancies.

Reproductive rights lawyer Julia Hamblin said in an article for a News Ltd press: “Contrary to popular belief, abortion is still an offence in NSW for the woman undergoing an abortion and the doctor performing it... it would be foolhardy to believe that Zoe's Law would have no impact on the legal status of abortion in NSW.”

“Once Parliament has declared a foetus to be a living person in one context, the overwhelming tendency would be for judges to take this into account – not conclusively, but perceptibly – whenever other issues involving the legal status of a foetus arise. Zoe's Law would add a new weapon to the armoury of those seeking to secure a conviction for unlawful abortion,” Ms Hamblin wrote.

Brodie Donegan, after whose daughter Zoe’s Law is named, says: “I believe women should be supported in which ever direction they head with their pregnancy. If they want or need a termination it should be available to them in a safe and legal environment. In the same instance if a pregnancy is cut short due to a violent and/or serious indictable crime then that should also be recognised and supported. I can’t see why we can’t do both.”

The New South Wales Bar Association and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists have voiced opposition of the bill.

NSW Parliament is expected to exercise a conscience vote in the lower house today.