Nae-Née – Birth Control: Infallible, With Nanites and Convenience for All - Nae-Née, #1

Nae-Née posits a world not unlike our own, as it confronts the major taboo of our time: the conflict between human overpopulation and the human desire to pass on one's DNA and one's culture. Our planet's ecosystem is being stressed past capacity to the brink of collapse due to biodiversity loss, rising sea levels, floods, droughts, overdependence on fossil fuels, and the climate changes that drive all that.
In short, the human species is in dire trouble due to overpopulation - its own. No one seems remotely inclined to sacrifice any comfort or control over their habits in order to save the environment and ultimately their own future existence, happiness, or sense of purpose. But there is a significant difference: nanite technology has advanced sufficiently to be of actual, practical use to physicians and scientists.
Nae-Née is a safe, reliable, user-friendly form of birth control. It is a microscopic nanite - a little robot. It contains a life-time supply of super-concentrated RU486, which the device releases whenever it detects a rise in hormones that indicates a fertilized embryo is about to implant itself. All that the inventors - a husband-and-wife team - wanted was a convenient form of birth control that would reliably prevent pregnancy without pumping a woman's body full of artificial hormones.
Its name literally translates as "not born" and was chosen by Avril, the wife, to reflect her husband's Scottish background and her own French ancestry. The story is told from Avril's point of view, a woman with Asperger's and a professor of women's medical history. The world's leaders have decided to make it the duty of every human being to participate in a bold new world policy, so they have drafted a treaty at the United Nations, and every nation has agreed to sign onto it.
This is done on a date that doom-sayers have anticipated with predictions of various - and often unrelated - dire consequences: December 21, 2012. Under the terms of the treaty, all women must have a government-registered Nae-Née device. Henceforth, every birth of any new human being must be licensed, and not everyone who wants a license to reproduce shall be granted one.