Euthanasia should legal?

so I have to write an argument why Euthanasia should be legal. I need a little help I have this sentence for one of my arguments but I dont really know how to support it. So if you have an sentences that could support this sentence that would be great.The sentence is.... 'Honestly, if it is legal to kill unborn babies, by having an abortion then it should be legal to be euthanized'.