Most birth control pills contain the hormone estrogen, which is suspected to encourage the growth of fibroids, but most pills contain such a low level of this hormone that they are unlikely to affect fibroids. If you decide to begin taking birth control pills, you should be sure that your doctor knows that you have fibroids so he or she can choose the appropriate pill for you. You should also watch for fibroid symptoms, and have a followup appointment three to six months after beginning the pill to check for any changes in your fibroids.