WASHINGTON (AP) -- Federal regulators will take a closer look this week at the safety of newer birth control pills that were heavily promoted as having fewer side effects and the ability to clear up acne and other hormonal bothers.

The Food and Drug Administration will hold a two-day meeting to discuss whether several birth control drugs that gained popularity in the last decade are more likely to cause blood clots than older formulations. The meeting could result in new warning labels on several popular contraceptives, including Bayer's pill Yaz, which was the best-selling birth control pill in the U.S. for 2008 and 2009.

Blood clots can cause heart attacks, strokes and other blockages that can be fatal in rare cases.