__________________
Its been a long time, how have you been? You know, when you MURDERED me.
Ahh..well let us put that behind us....for science....you monster....
Basically, he choked her enough to make her pass out, but that was it. Afterwards, she was okay(recovering from a choke isn't really difficult), but she knew that the one person she loved, had just tried to kill her, she had no reason to keep going. So she kinda...willed herself to die, and giving birth to Luke and Leia did it.
It was a homage to Vader's force chokes in the original trilogy, except here Vader is younger and without the suit, and rather than doing it to imperial soldiers/officers, he did it to padme, who had luke and leia.
Padme losing the will to live was the lamest thing about the prequels.
__________________ "Your Lord knows very well what is in your heart. Your soul suffices this day as a reckoner against you. I need no witnesses. You do not listen to your soul, but listen instead to your anger and your rage."