Asklemmy

"Now this, bhikkhus, is the noble truth of suffering: birth is suffering, aging is suffering, illness is suffering, death is suffering; union with what is displeasing is suffering; separation from what is pleasing is suffering; not to get what one wants is suffering; in brief, the five aggregates subject to clinging are suffering."

He didn't say anything specifically about the ethics of human reproduction. He taught that craving sense pleasures leads to suffering. The monks that followed him were celibate. But he knew few would follow that path. So he taught a simplified code of ethics for householders (don't kill, don't lie, etc.) and assumed that there would always be people who want to make more people. Rebirth was an important part of his doctrine. The volitional actions you perform in life create karma which then, after your death, produces another birth. Escaping the cycle of karma and rebirth by letting go of the concept of self, of the idea of me and mine, was the ultimate goal of his path. And it's only possible to get there in a human body. So in that sense he was not an anti-natalist.

I never checked and actually fear to dig into this matter, given how much time has passed and how people have been twisting everything. But I do recall him having monk go take a shelter in a house of a prostitute, and a bunch of monks learning from prostitutes (definitely did happen in Japan). So no, he definitely didn't have an issue with sex or procreation