Fertility is a multifaceted trait; the degree to which a woman is fertile is dependent on a multitude of other traits and characteristics. It seems pretty clear that a desire to have children was not really necessary in the past in order to end up with lots of children. Having children was just something you did, so most couples had children and, consequently, fertility was driven by other traits. Perhaps desire to have sex, ability to earn income, etc. But things have changed. Now it seems pretty clear that the most important factors in fertility are A) whether or not the woman pursues college and a white collar career path, and B) whether or not both parents have an innate drive to have children (those two traits are probably related).
So yes, fertility has always been positively selected for. But the traits that drive fertility have changed as a result of our changing environment. So evolution is selecting for different traits at the moment.
they will in combination with economic incentives. In a world where skilled labour is rewarded and the cost of raising a child is higher and higher, whose going to pay for your large family? When people in developed economies today date, do you think they favour high social status and intelligence or sperm count?
Fertility and some other biological traits have always been positively selected for. Is the world overrun by virile, promiscuous musclemen and women with wide hips?