While a federal judicial panel did not rule on the scientific merits of Mirena IUD lawsuits alleging that it causes intracranial hypertension, the judges have rejected a request to centralize the proceedings.

Last spring, a group of nine separate plaintiffs asked that their Mirena IUD lawsuits be centralized in a multidistrict litigation (MDL), which transfers all cases to one federal judge in all pending civil lawsuits of a similar type filed throughout the United States.

In September, both sides in the Mirena intracranial hypertension lawsuits presented their arguments about a MDL. The plaintiffs had requested that their Mirena lawsuits be centralized in either in the Middle District of Tennessee, the Northern District of Alabama or the Western District of Kentucky.

The federal judicial panel acknowledged in their order that there exists persuasive reasons to centralize the Mirena lawsuits, such as “shared factual issues arising from allegations that the synthetic hormone released by the Mirena IUD (levonorgestrel) causes abnormal elevation of cerebrospinal fluid in the skull, resulting in a neurological condition known as pseudotumor cerebri (PTC) or idiopathic intracranial hypertension, and that Bayer failed to warn consumers of this risk” as well as the fact there is already a multidistrict litigation for the Mirena IUD concerning another type of injury — uterine perforation and migration.

But reasons for not centralizing the Mirena IUD intracranial hypertension lawsuits were more compelling, according to the judges’ order. Namely, all nine plaintiffs are using the same attorney and all nine Mirena lawsuits also list the same defendant, Bayer, which is represented by national counsel.

Bayer has maintained that it “stands ready and willing to share any overlapping discovery upon entry of an appropriate protective order (which already has been entered in two actions).”

“Given the few involved counsel and limited number of actions, informal cooperation among the involved attorneys is both practicable and preferable to centralization,” the judges ruled.

Bayer had previously argued in a written motion opposing the multidistrict litigation that the plaintiffs’ claims had no scientific basis and instead were attempting to manufacture the litigation.

Intracranial hypertension, also known as pseudotumor cerebri (PTC), puts pressure on the optic nerve, resulting in blurred vision or temporary black-outs. Migraine-like headaches are also hallmarks of the condition.

There are currently about 600 Mirena lawsuits already centralized in the Southern District of New York, however that litigation is limited to claims where women suffered internal injuries after Mirena moved out of place, puncturing the uterus and migrating to other areas of the body, causing internal injuries, infections and leaving women unprotected against unwanted pregnancy.

The Mirena brain pressure lawsuits allege that Bayer knew of the link between levonorgestrel and intracranial hypertension but failing to warn of it. Other countries including South Africa and Hong Kong, the warning labels on Mirena disclose information about the risk.

The Mirena IUD is implanted into the uterus to provide protection against pregnancy for up to five years. It contains a steroid reservoir that release levonorgestrel, a second generation progestin used in many forms of birth control.

More than 15 million women worldwide use the Mirena for birth control. It received U.S. Food and Drug Administration (FDA) approval in December 2000 as a long-term contraceptive device.