They were a busy couple - two jobs, a house in the suburbs. Nancy and Edward Hart wanted a baby, but the conversations usually ended with "later, later," until suddenly there was no more later. Edward Hart died of cancer on June 14, 1990.

But the couple's dream of having a child did not die with him.This week, Nancy Hart, 40, filed a first-of-its-kind lawsuit against the U.S. Department of Health and Human Services and the state of Louisiana on behalf of her 3-year-old daughter, Judith. She's asking for $710 a month from her husband's Social Security for Judith.

The problem: Louisiana and the Social Security Administration don't recognize Judith as Edward Hart's "natural child." The reason? She was conceived after he died.

"Under Louisiana law, Judith has no father," said Nancy Hart's lawyer, Kathryn Kolbert of the Center for Reproductive Law and Policy.

It is a legal and medical tangle: Doctors warned Edward Hart that chemotherapy could render him sterile if he survived. So, before undergoing treatment, he donated sperm to a New Orleans sperm bank. Three months after his death, his widow was artificially inseminated with her husband's sperm. Judith was born on June 4, 1991.

Nancy Hart, an Episcopal school music teacher, wrote to 54 members of Congress for Social Security help. But Social Security administrators ruled that Judith was not a "natural child" of Edward Hart because Louisiana law dictates that conception must occur before death to determine heirship.

"It appears Louisiana never contemplated this situation, nor did any other state in the nation," Kolbert said. "The law has got to catch up with the medical science."

Ellen Moskowitz, a medical ethics lawyer with the nonprofit Hastings Institute, said, "There's a great deal of legal confusion in respect to new reproductive technologies, because they are so new."

Nancy Hart said her husband encouraged her to have a child even if he died. Judith, meanwhile, knows only that her father died before she was born. The Social Security money would supplement Nancy Hart's modest teacher salary and the money she makes as a church organist.

But "the larger issue is I want my daughter to be recognized as her father's child," she said. "I want her to have a daddy."