Here's an extreme position on childlessness. To be clear, I'm just presenting this idea--not advocating for it. Philosopher David Benatar claims that coming into existence is always a harm to that person, and therefore it is morally wrong to reproduce.
The core of Benatar’s argument lies in the asymmetry between the good and bad things in life: “The absence of bad things, such as pain, is good even if there is nobody to enjoy that good, whereas the absence of good things, such as pleasure, is bad only if there is somebody who is deprived of these good things.” We would not miss the good things if we had never existed. But even those of us with the luckiest and happiest of lives suffer greatly, merely from the fact of existing. We might regret that we never had the chance to experience bearing a child or parenting. But we do not regret that our unborn child never got to experience the good things in life, any more than we regret that nonexistent Martians never get the chance to fall in love, prosper, or have baby Martians of their own. We very well might regret, however, having brought into existence a child with an unhappy or unfortunate life.
For Benatar, our primary moral obligation ought to be toward the unborn person, but we almost never do so. Benatar makes it clear that “one can never have a child for that child’s sake”—it is always done for the sake of the parents, the state, the nation, or done without much thought at all. Prospective parents might hope that their child will join the ranks of the lucky, but there is no guarantee. And even if they should be so happy, they will nevertheless suffer from daily disappointments, the frustration of goals, the loss of their loved ones and their own eventual death. Our state of constant striving, as Arthur Schopenhauer recognized, brings us only discontent. The conclusion, to him, is plain: “If the act of procreation were neither the outcome of a desire nor accompanied by feelings of pleasure, but a matter to be decided on the basis of purely rational considerations, is it likely the human race would still exist? Would each of us not rather have felt so much pity for the coming generation as to prefer to spare it the burden of existence, or at least not wish to take it upon himself to impose that burden upon it in cold blood?”
It’s difficult to take Benatar’s argument seriously if you apply it to yourself, to your children, or to any person who actually exists. Indeed, Benatar recognizes that existing humans have many good reasons to want to keep living—his argument only applies before an individual has come into existence.
Instead, Benatar argues that we are morally obligated not to procreate. Ever. The human race should allow itself to go extinct. We should take all precaution against pregnancy and abort those that accidentally occur. The only possible exception is that we should minimize the suffering of the final generation of humans, so we should implement phased extinction so that the final generation is relatively small. He does not advocate suicide.
For Benatar, we must choose childless not from a place of liberating, higher-order level of self-actualization, but from a deep and clear-eyed pessimism about human existence. The arguments of those who dislike children or who want to pad their own pocketbooks or live unfettered lives have no play here. He prefers to face squarely the sadness and frustrations of life head-on rather than shunt them to the side. He decries the “smug macho tone” of those who admonish him to “grin and bear it” as “an indifference to or inappropriate denial of suffering, whether one’s own or that of others.” Benatar urges a clear-eyed look at our common experience of suffering. He knows that most of us won’t accept it; we tend toward optimism. We adapt, we accommodate, we habituate to the bad. And we are unwilling to think rationally about the harm we are doing to our children simply by bringing them into life. A lack of regret about one’s own suffering and existence makes it easy for people to unthinkingly procreate, to spread the suffering to the next generation. “They may be happier than others,” he stresses, “but that does not make them right.” Those who cheerfully procreate “play Russian roulette with a fully loaded gun—aimed, of course, not at their own heads, but at those of their future offspring.”
 David Benatar, Better Never to Have Been: The Harm of Coming into Existence (Oxford: Oxford University Press / Clarendon Press, 2006)., 14.  Benatar, Better Never, 35.  Benatar, Better Never, 35.  Benatar, Better Never, 2.  Benatar, Better Never, 76-77.  Schopenahuer, “On the Suffering of the World,” Essays and Aphorisms, trans. and with an introduction by R. J. Hollingdale (New York: Penguin, 1970), 47-48.  Benatar, Better Never, 211.  Benatar, Better Never, 64-69.  Benatar, Better Never, 211.  Benatar, Better Never, 92.