I frequently get emails asking "How can I have twins?" In fact, one of the most popular articles on this site is my listing of Top Ten Ways to Increase Your Chances of Having Twins. In that article, I ask readers to tell me why (they think) they had twins. I've compiled those into a new feature: How to Have Twins: Reader Stories. From family history to birth control pills, parents offer their theories about conceiving twins or mulitples.