I'm a total non-biologist, but I'm just putting this idea out there.
My understanding is that a woman's sense of smell allows her to figure out who is a good immune match --- men who smell good to her have complementary immune function and she would have healthier children with them. Oral contraceptives (OCs) interfere with this function so that a woman on OCs might marry someone who isn't genetically complementary and doesn't smell good to her after she goes off them. The number of women who chose their husbands while taking oral contraceptives has increased enormously since their invention. I wonder whether this has any social or medical implications: are the children of women who met their husbands while taking OCs less healthy in some way? Are these couples more likely to get divorced?
Anyone know any research on this idea?