Adam Smith may be noted for borrowing the ideas of other people, for his story-telling and myth-making, but on one matter at least he fails abysmally. That is the question of sex. All I have been able to find is this:
Poverty, though it no doubt discourages, does not always prevent marriage. It seems even to be favourable to generation. A half-starved Highland woman frequently bears more than twenty children, while a pampered fine lady is often incapable of bearing any, and is generally exhausted by two or three. Barrenness, so frequent among women of fashion, is very rare among those of inferior station. Luxury in the fair sex, while it enflames perhaps the passion for enjoyment, seems always to weaken, and frequently to destroy altogether, the powers of generation (Wealth of Nations, I.8.37).