Sorry if I was being overly pedantic, but you used the term "adultery" [as distinct from "fornication", "living in sin", or any other such terms]. Words mean things, and adultery specifically means someone who is married having relations with someone outside that marriage.
BTW, I understand that gestation periods for first children used to often be rather shorter than for subsequent ones. Whether or not pre-marital relations were ever considered "acceptable", they certainly happened; provided the people involved were married before the baby came along the child would be considered legitimate and not have any stigma attached to its rapid gestation.
Of course, one thing that was very different 150 years ago is that many more people married before becoming independent of their parents (and even after being married, they still stayed close to Mom and Dad). I suspect this did a lot to help marriages work, since the husband and wife would grow together instead of joining only after each was fully grown, mature, and independent.
Errr... I didn't do that, and I was agreeing with you. Sarcasm. I was tweaking the 'I think I'm holier than thou, but I'm really not holier than a cheese sandwich' posters.