OAKLAND -- Three women are challenging the Alameda County sheriff's policy of mandatory pregnancy tests for female detainees under age 60 in a lawsuit filed this week by the American Civil Liberties Union of Northern California.

The lawsuit, filed in Alameda County Superior Court against Sheriff Gregory Ahern on Monday, alleges the tests are intrusive, in violation of the state constitution and state law, and appear to be unrelated to providing appropriate health care to women in the jails.

Sheriff's spokesman J.D. Nelson said Tuesday that the department had not yet been served with the lawsuit and therefore could not provide comment.

The lawsuit seeks court intervention and a change in policy allowing detainees the option to refuse a pregnancy test. Women being tested now include arrestees in jail for a as little as a couple of hours and women sure they cannot get pregnant, the lawsuit says.

"As a result, female arrestees in Alameda County suffer humiliation and even greater distress, when, for example, they have to take the pregnancy test despite knowing that are not able to become pregnant due to age or infertility; they did not know they were pregnant and have to receive that information from someone other than a trusted health care provider; or they were trying to get pregnant and have to receive the news of negative test results from someone other than a trusted health care provider," the lawsuit reads.

Plaintiff Susan Harman was 69 years old and said she was humiliated to have been forced to take a pregnancy test at the North County Jail after¿ being arrested at a protest related to the Oscar Grant shooting in July 2010.

Plaintiff Nancy Mancias says she tried to refuse a pregnancy test at the jail after being arrested at an Oakland political demonstration in 2012, but an officer threatened to take her to Santa Rita Jail unless she took the test.

A third plaintiff using a Jane Doe pseudonym is a mother of two arrested this year for resisting arrest during a traffic stop who, like the others, wants women to have the right to refuse the test.

"I was intimidated and bullied by the female officer who was processing me. I felt completely violated," said the woman, 44, of San Rafael. "We don't want other women to go through this."

State law says every person, including individuals in police custody, have the right to refuse medical care, says the ACLU. The organization says it hopes to bring Alameda County in line with neighboring counties, like San Francisco, which give women the option to take a pregnancy test as part of a broader health screening.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.