A Los Angeles dockworker says she was penalized on the job for having a child — and attorneys with the American Civil Liberties Union are now seeking workplace policy changes and monetary compensation for pregnant workers at 29 ports along the West Coast.

Los Angeles port worker Tracy Plummer filed pregnancy discrimination charges Thursday with the U.S. Equal Employment Opportunity Commission. She brought the charges against the Pacific Maritime Association — which represents West Coast port companies — and the International Longshore Workers Union (ILWU).

In the charging documents, Plummer says she has worked at the ports of Los Angeles and Long Beach since 2007. She had a child in 2015, and says her pregnancy put her at a disadvantage when it comes to accruing hours. Building up hours can help workers low on the totem pole — known as "casuals" — gain admission into the well-paying ILWU.

Plummer says she was not allowed to rack up hours while she was off the job due to pregnancy. But, she alleges, other workers get to keep accruing hours when they're out for other reasons, like work-related injuries or illnesses.

"I have been disadvantaged, as compared to my non-pregnant peers who are similar in their ability or inability to work, in accruing the seniority needed to receive raises and qualify for promotion from 'casual' status to full-time," Plummer writes in the charges.

Southern California ACLU attorney Melissa Goodman said Plummer's experience is shared by female dockworkers up and down the West Coast.

"What happens to many women who we've spoken to is that they're penalized for having children, essentially," Goodman said.

In a statement, ILWU spokeswoman Jennifer Sargent Bokaie said, "There is no policy or practice of granting hours credit for absences of any kind, except for military veterans as required by federal law."

The Pacific Maritime Association declined to comment.

The ACLU estimates there are about 5,000 "casuals" working at the Los Angeles and Long Beach ports, and says roughly 800 of them are women.