It was a tantalizing job opportunity for Nikki Columbus: a chance to direct the performance program at MoMA PS1, the Queens museum known partly for its robust and inventive live art, music and dance series. After months of meetings and conversations with two of the museum’s leaders, Ms. Columbus was formally offered a position as curator of performance in August 2017. But just a few weeks later, after Ms. Columbus mentioned to the museum’s chief curator that she had just had a baby, Ms. Columbus says, the offer was rescinded.

Now Ms. Columbus, 43, has filed a complaint with the New York City Commission on Human Rights, asserting the museum discriminated against her in violation of the city’s laws on caregivers, pregnancy and women’s rights.

“This is a blatant violation of the law,” said Elizabeth S. Saylor, one of Ms. Columbus’s attorneys. “This type of discrimination, like sexual harassment, stymies women’s advancement in the workplace.”

In her complaint, Ms. Columbus said the museum tried to assert, inaccurately, that she had turned down its job offer. But the museum on Friday would not discuss the matter, citing its respect for privacy in personnel matters.