The estate of an Omaha woman who died while using the NuvaRing contraceptive is suing its makers, claiming the device caused a deadly blood clot.

The lawsuit filed Monday in U.S. District Court in Omaha says 43-year-old Ann Tompkins of Omaha died on Feb. 23, 2009, about five months after she began using NuvaRing.

The lawsuit seeks damages from various pharmaceutical companies that currently or at one time manufactured and sold the contraceptive, a flexible ring that is inserted in the vagina and releases hormones to block conception.

About 500 such lawsuits have been filed since 2007, but this is believed to be the first NuvaRing lawsuit filed out of Nebraska.