One of the most common criticisms of the prequel trilogy is the explanation behind Padme’s death in Revenge of the Sith. There was little room to keep her alive, due to her absence in the original trilogy, and some see her downfall as a poorly-conceived plot device.
Specifically, shortly after she learns of Anakin’s turn to the Dark Side, Padme is brought to Pollis Massa to give birth to Luke and Leia. There, it is said that, while medically healthy, she is dying because of a “loss of the will to live.”
The terminology here is a bit vague, but some concluded that the cause of her death was a broken heart at learning the news of Anakin’s fall to the dark side. That stems from the fact that prior to this scene when Padme confronts Anakin on Mustafar, she cried that he was breaking her heart in an attempt to bring him back to the Light.
If you want to delve into fan theories, there’s the idea of Palpatine having his hands all over this. However, let’s stick to the canon story, where the actual cause is never officially stated beyond those words, but can be pieced together to something deeper.
First, Anakin had Force choked Padme in that same scene on Mustafar as he believed that she brought Obi-Wan there to kill him. While Anakin was most likely not attempting to kill her, we’ve seen the consequences of Vader’s Force choke before. At the very least, it put Padme in a bit of a dangerous state that was only exasperated during childbirth.
It then becomes feasible that Padme felt she fulfilled her purpose by giving birth to her children, consequently losing the will to live. However, that theory takes a bit of a hit from the fact that she claimed there was still good in Anakin, thus work to be done before her death.
Anakin foresaw and feared Padme’s death in childbirth.
Then there is the second element that Padme had been expected to die in childbirth in the first place. The original spark behind Anakin’s turn was the nightmare that saw his wife dying in childbirth. He thought the Dark Side would grant him the power to prevent that reality from coming true.
Ultimately, though, with their relationship severed, he lost the ability to change that fate, or perhaps never even had it. Padme was always meant to die this way, regardless of whether her heart has broken or not.
Could that be the ultimate reason for her death, though? Perhaps, as the film says, she lost the will to live, and Padme herself says Anakin was breaking her heart. The entire picture, though, has a bit more to it than that.