The death of Padme Amidala Skywalker

One of the most tragic moments of the entire saga. From the scene on the landing platform at Mustafar through to the end of the film, there is a sense of melancholy that can't be shaken. The sense that events have overtaken the players involved and that the outcome, even though we as an audience have known it for almost 30 years, is beyond salvaging, even for the characters of the piece.

Padme lies in state, her beautiful face framed forever in a swathe of flowers, her state funeral trailing solemnly through Theed towards her final resting place. But look closely and you will see that Padme appears pregant.
Despite the birth of the twins on Polis Massa, she appears to have perished while still with child.
Gruesome though this image may be, there is every chance that this action may well have saved the galaxy from tyranny far lengthier than the twenty years it took for Luke to come into play.

Both Anakin and Palpatine knew Padme was pregnant, but with her death the Emperor could relax, knowing that any offspring of Skywalkers could not grow and be trained to challenge him in the coming years. And Anakin, believing that he had not only murdered his wife but his unborn child too, would fall even deeper into despair and hopelessness, and therefore become even more susceptible to the dark side.
In short, Palpatine had completely won.
But the truth was very different. As we know, Padme not only had one but two children, twins who were separated and sent to live with very different foster parents. But, vitally, they were thought dead. After all, as far as Anakin knew, Padme had died on Mustafar. And the Emperor, despite not knowing the actions of her final hours, knew of her funeral on his homeworld of Naboo.
The Jedi were no more, the galaxy belonged to the Empire.

If either Vader of the Emperor had known of a childs survival they would have been hunted down and likely found. As it was, there was no reason for Vader to scour the galaxy for any child. His wife and unborn child were dead.

Yoda's idea to bury Padme like this was genius:

Page 412 Revenge of the Sith novel - "Pregnant she must still appear. Hidden, safe, the children must be kept."
This masterstroke gave the galaxy a chance...