Socialism deals with money, primarily. A nanny-state is Authoritarianism.
Ok, well this is semantics, splitting hairs, etc. It's the actions and what's done (or not done) that actually matters.
Think of it this way; Child restraint seats in automobiles. People don't need a law to protect their children, but they demand a law to protect other people's children. What they fail to understand is that they are giving the state yet another way to intrude into their lives, and that these demands have repercussions...such as having another reason to be stopped by cops. "Scared" cops, as admitted by Fivezeroes.
Well, I can't speak for anyone in the law enforcement business, but in general when someone chooses to go into the law enforcement business they ought to be getting training on the risks involved (I can't imagine that they don't); if a person doesn't want to deal with those risks then they should look for a different career, look for ways to better handle those risks (invent something, come up with better procedures, etc.), or find ways to reduce or eliminate most or all of those risks.
I'm not saying that I approve or condone of the existence of those risks. In fact, you could basically say that I fall under the category of someone who wants to find ways to reduce or eliminate most or all of those risks & that's why I'm also a participant on the Zeitgeist Movement forum. My interest is essentially to try to eliminate the dependency on money and trade to in turn phase out crime, corruption, war, poverty, pollution, etc. by advocating the use of automation and advancements in technology, persuading people to study robotics, engineering, etc. The idea is that society's problems are technical, not political, and the idea is to reduce or eliminate the need for the state or law enforcement.
Developing a special kind of incubator, or coming up with techniques for transferring a fetus to a surrogate mother, are solutions that would benefit a mother that either doesn't want to continue a pregnancy, has a medical problem or complications that pose a problem to the pregnancy, a mother or father that wants to keep the child, the child itself, and a society that doesn't condone killing unborn children or considers it immoral.
Regarding laws to protect children or other people, instead of having laws mandating procedures, design and build technology so accidents won't happen anymore (or at least to significantly reduce them). For example, this could be achieved with the use of air bags, sensors, communication between each vehicle and intersection systems, driverless cars, etc. (in fact, some of these ideas have or are starting to be implemented). Imagine no more need for traffic lights, traffic jams being a thing of the past, cars alternately criss-crossing each other through intersections (like internet packets through routers), etc.
The "real politik" of Rights is that they are backed by violence. We only have those Rights that we can defend. This is why the 2nd amendment is so vital. As you've pointed out, the unborn are defenseless....so no, my statement cannot be inverted. Even in a "gestalt" mother/unborn situation, the mother alone would have to advocate for their combined Rights.
The idea behind having a state is specifically to preserve rights regardless of an individual's ability to defend them; otherwise, we have anarchy.