我这方面研究不多，只能说我知道的，都是实例，并非耸人听闻。Of course, I think the probability that a woman has some side effects due to taking birth control pills is low, otherwise those drug won't be approved by the FDA. If you search on medline, you should be able to find some articles published on medical journals focusing on this issume. As to what is the best way for birth control, I don't know.