Please realize that we have had only 2 or 3 generations of Christianity in this part of the world. The difference in the position of women in society is huge when compared with the results of 1700 years of Christianity in the West.
Again with the hazy location! Africa is a giant continent! Please specify, localize, and/or characterize the type of human habitation (squalid Lagos slum; bushman settlement on edge of desert) you are talking about!
And you are wrong to make this about "Christianity." In Muslim societies, too - even where polygyny is actively practiced - loose women are not tolerated, and societal resources are not squandered on helping them raise their broods.
Same applies to 19th-century Japan, ancient Judea, and a variety of other civs.
Has nothing to do with Christianity or "the position of women in society." For most of human history, in the majority of societies, bastardy was reviled, and loose women were consistently punished.
Regards,