Maureen Sheridan’s search for her biological mother began in the late 1990s, after she had a precancerous mole removed and her doctor suggested she look into her medical history. That research led her to the New York Public Library, where in 2001, sifting through a vast trove of vital records, Ms. Sheridan discovered the name she had been given at birth: Beth Lyons.

She does not know the name of her biological mother, who gave her up for adoption in 1976, because New York State laws dating to the 1930s deny all adoptees access to their original birth certificates. Still, Ms. Sheridan said, at least she learned that her mother had “cared enough to give me a name.”

With two sons of her own now, who have both had medical scares, Ms. Sheridan, 38, an administrator at the New School, said she felt even more compelled to unearth her medical history, even if she never connects with her biological mother.

“My original birth certificate sits in a building in New York City, and I’m not entitled to it,” she said. “I have a big issue with the fact that, as a group, we’re kept by law from accessing our own records.”