My first thought was birth control pills. Before anybody freaks out, I'm NOT against birth control pills but as I understand it over the long term I hear they do add certain health risks to some women including an increased risk of cancer and blot clots that could lead to heart attacks and strokes. I'm not a doctor so this should not be construed to imply any medical advice other than to seek the advice of one's own doctor but I've heard its best in some cases not to be on birth control pills forever but rather alternate between pills and other methods then consider his or her surgical options once all the bedrooms are filled with all the kids you want.
Birth Control The Pill & Breast Cancer Risk - WebMD
Study: Newer Birth Control Pills May Double Blood Clot Risk
My second thought was more stressful lives including being more likely to work outside of the home while still doing a good deal of domestic stuff often as single moms. I don't mean to sound sexist but the stereotype of men not being able to multitask well and with women its a breeze, I don't know who came up with that one . My observations of the women I know is they'll will push themselves to do what they must but they do have a breaking point and are on the verge of a meltdown if too much is on their plates. I think men can handle stress a lot better.
PS. This is why if you care you should never let a woman have the remote control.