If you look online, translation for 投胎 is 'reincarnation'. It suits phrases like 投胎转世 but often does not feel quite right in other context.
Not sure if anyone would laugh if you translate it into
'What's the hurry, on the way to reincarnate?'
投胎 is one of the steps, an action, of the entire reincarnation process. But I'm short of proper English word or simple phrase here. Also hope it's a fun question.