"But contraception is against their (religion/morals/ beliefs/culture/heritage/whatever)."

I think it's more that contraception aids are not readily available and there is no education about contraception. I don't think the mother who offered one of her five kids to the NY Times reporters sat down one day and said, "Hey, I know. I think I'll raise a bunch of kids to die of starvation because contraception is against my moral beliefs." I think she just had no choice.