See, this is where extreme opinions meet. There have been countless incidents where our feeble language has failed miserably to describe reality, and this is one of them. Basing your actions, or paradigm on ideas built out of words, instead of reality its self is an enormous mistake, and leads to millions of hours of human life wasted, squabbling over definitions. In reality. It's like mistaking a single painting of a mountainside for having depth. The only way you can really have any amount of faith in your own ideas is if you take a look from as many standpoints as possible.

From the most objective, non-human standpoint, it does not matter what we do, we will all die eventually, no matter how many babies we do, or do not abort. The only thing left of us will be crumbling ruins on one, or more, dry, dead planets.

From an environmental standpoint, having inadequate children can both cause increased irresponsibility of our population, and an increased population overall.

From a societal standpoint, inadequate, fatherless, or children from wrecked families are more likely to be unproductive, or produce more inadequate, fatherless, and psychologically unhealthy people. This is a dangerous pattern, which can threaten almost anything made out of family units.

From an individual standpoint, a baby that you're not ready for could easily ruin your life, bring incredible gratification, or do both, depending on the circumstances. This is standpoint is rather neutral, but leans towards the negative.

From an objective, close-up standpoint, the destruction of this thoughtless, non self-aware blob of flesh with human DNA would not matter to it whatsoever. It is not capable of understanding anything until much later after birth, so its destruction would mean nothing to it, there is almost no distance between its oblivion, and total oblivion. It does not hold any invested work belonging to people other than the parents, so it is the choice of, and only the choice of the parents whether or not it gets to live.

From the standpoint most people take, there is value in its potential, and the child could be a great person in the future. For slightly more pessimistic, or realistic people, the value is also tainted with required investment, and work, and that the taint may exceed the greatness. "Said child could become a great man if he grows up, or he could become a dangerous, or mediocre one. Regardless of the possible outcome, to raise this potential human would take thousands of hours of work."

From the most common religious standpoint (christianity, or catholicism), the more extreme you get, the earlier a fetus becomes human. Starting with the least extreme; birth, to the most extreme, before conception. Other variations include things carrying human DNA, or DNA whatsoever.

From my personal standpoint, you are not human until the day you become self-aware. Personally, that memory is very vivid. I was four, I looked up, and realized that I was alive. There is no warping in that statement, either. I went to my father, and argued that I was born four years old. However, things are a little more complex than that, and must be different for every person. I recognize several levels of intelligence, built into each other in an emulative fashion, and this is where my opinion is derived from. The first level of intelligence is the processing power of the universe its self, calculating between plank-time units where every single particle in the universe will be next. The next is the level of intelligence between atoms, or molecules, where several stable things are automatically found, and propagated. The very existence of a stable, two-way chemical reaction is due to the calculations of those atoms, so-to-speak.

The next level is a lot closer to us, and in fact branches off from other levels of intelligence. This is the level of bio-chemicals. The intelligence in this level has a specific name, or several names, actually. It is known as natural selection, or evolution, and it is the tendency for a large number of organic chemicals to, over time, perfect themselves. Finding the most efficient possible systems through sheer trial, and error.

The next level is intelligence by neurons. Or brains. You've been living around these all of your life. This is the only kind of intelligence with the human kind of "consciousness". No other intelligence's have this.

The next level is societal intelligence, or intra-personal intelligence. Intra-personal intelligence deals with the flow of information its self, and can get extremely complex at times, and often participates in the higher tier.

The next is super-societal, which is the interactions between societies, or intra-personal clusters. This level is the level in which things like war happen.

Whatever, you get the picture. My point is that non self-aware beings lack the neural form of intelligence, and are incapable of actively participating in the intelligence's above, which is what I measure as value. Fetuses especially lack this even moreso than animals, because they have never received stimulation that correlates with the outside world. They certainly have the potential to, in the future, but they require a ton of effort to be sacrificed so that they may fulfill this potential.

This is just my opinion, and I was not spoon-fed it by any religious nutter, so feel free to suggest a change. I will not be offended. Just remember that I don't take emotionally warped, or insipid answers as relevant.