The basis for Catholic teaching on sex and reproduction stems from the divine and natural law and are completely unrelated to "an era when lots of children were needed to assist with the family's economy".

Gaudium et spes [87]: "But there are many today who maintain that the increase in world population, or at least the population increase in some countries, must be radically curbed by every means possible and by any kind of intervention on the part of public authority. In view of this contention, the council urges everyone to guard against solutions, whether publicly or privately supported, or at times even imposed, which are contrary to the moral law. ... Men should discreetly be informed, furthermore, of scientific advances in exploring methods whereby spouses can be helped in regulating the number of their children and whose safeness has been well proven and whose harmony with the moral order has been ascertained."