An Indiana diocese asked a federal court on Monday to reject a lawsuit by a former parochial school teacher who claims she was fired for violating Roman Catholic doctrine by using in vitro fertilization to try to get pregnant.

The Diocese of Fort Wayne-South Bend and St. Vincent de Paul school in Fort Wayne argued in court documents that Emily Herx's lawsuit should be barred by a federal law that prevents religious workers from suing their employers for job discrimination. That so-called "ministerial exception" law was upheld by the U.S. Supreme Court in January.

Further, diocese attorneys say any court review of church teachings or employment practices would violate the constitutional separation of church and state and guarantees of religious freedom.

The Roman Catholic Church shuns in vitro fertilization, or IVF, which involves mixing egg and sperm in a laboratory dish and transferring a resulting embryo into the womb.