A resident of Michigan has filed a Yaz lawsuit that will join the multidistrict litigation (MDL) that is currently underway in the U.S. District Court for the Southern District of Illinois concerning Yaz side effects.

Karen Mathies’ lawsuit was filed on July 5, 2012. Mathies started taking Yaz on February 24, 2009. After using the pills for two months, she developed a pulmonary embolism which threatened her life and resulted in permanent injuries. Pulmonary embolisms are caused by blood clots that block the artery in the lungs. Sometimes those blood clots can start in the legs and cause deep vein thrombosis.

Mathies’ lawsuit joins thousands of other similar lawsuits that have been filed against Bayer over the company’s controversial birth control pills. Research has linked the synthetic progestin drospirenone (a primary active ingredient in Yaz and its sister drug, Yasmin) to various side effects, including heart attacks, strokes and gallbladder disease. The FDA even held a panel advisory meeting on the fate of Yaz after it was found to cause blood clots. Unfortunately, the panel opted to keep Yaz on the market and only add a stronger warning about the blood clots.

Now, newer studies are showing that Yaz and Yasmin may also cause irritable bowel syndrome and kidney stones. These thousands of lawsuits — not to mention claims about the newest side effects that may be opening the door to thousands of more lawsuits — may be why Bayer has decided to settle almost 1,500 cases. The amount of the settlement hasn’t been disclosed yet, but with so many lawsuits being a part of the settlement, it could be record-breaking. This is particularly interesting considering the $110 million that was a part of a separate settlement agreement in only 500 cases.

It seems that the Illinois MDL just keeps growing every day, with more and more plaintiffs joining in. Even with these settlement agreements taking place, Bayer is in for a lengthy fight. For now it looks as if Bayer is going to try to walk away with the least amount lost as possible, but this could still mean more than a billion dollars in payouts.