A former assistant professor at a Christian university has accused the school of firing her "for becoming pregnant out of wedlock", according to allegations in a lawsuit.

The dean of Northwest Christian University, Dennis Lindsay, allegedly told the former assistant professor, Coty Richardson that "having a child out of wedlock while still continuing a relationship with the father was inconsistent with the university's core values and mission and set a 'bad example' for the students".

Lindsay gave Richardson two choices, according to the lawsuit: She could either marry the father and provide proof of their union, or she could claim the pregnancy was a mistake and disassociate with the father.

"When Ms Richardson refused the university's demands and requested privacy in her personal life, she was locked out of the university and her employment was terminated," the suit alleges.

Northwest Christian University declined to comment, and said "we don't feel that's in the best interest of anyone involved in the case."

Richardson is seeking $650,000 in damages and attorney's fees.

There is a petition calling for her reinstatement which has drawn 671 signatures in under a month.

The university offered her a $15,000 severance package, which she refused. She told Oregonian that "the opportunity was there, but in my heart, I feel that the whole situation was handled completely wrong and I wouldn't feel good about [accepting a separation package] on the terms it was given."