A top executive for the Child Mind Institute says the charitable organization wasn’t too child-friendly when she became pregnant. Lisa Hernandez Gioia, the institute’s director of development, is suing the nonprofit, claiming president and founder Dr. Harold Koplewicz, a respected child psychiatrist, made the workplace so uncomfortable, she had to take short-term leave. In a complaint filed Friday in Manhattan Supreme Court, Gioia claims “Koplewicz’s treatment of her completely changed” after she revealed she was pregnant in March and she was marginalized. The suit alleges that Koplewicz created an “overtly sexualized and deeply hostile atmosphere.” Gioia also claims she didn’t receive a yearly bonus owed her, and had to take short-term leave due to complications brought on by “workplace stress.” “This is a clear example of antiquated stereotypical thinking on the part of someone who should know better,” Gioia’s lawyer, Andrew G. Celli Jr., said about Koplewicz. But other sources close to the institute claim that concerns about Gioia’s role fund-raising for the organization grew well before she revealed she was pregnant — a claim which Gioia’s rep denies. CMI’s lawyer declined to comment, but a source said: “There are 100 people who work here, 80 percent are females. There hasn’t been a single complaint.” Koplewicz has treated the children of many New York boldfacers, and the CMI annual gala — which will be held tomorrow — last year brought out Matt Lauer, Robert De Niro, Chuck Close and Jimmy Buffett. “Fortunately, in her absence, contributions are up 20 percent and around 900 will be attending to support CMI and its groundbreaking work,” our source said. Gioia’s still employed by CMI, sources say, and her name is still listed on the company’s Web site.