A judge here said Tuesday that a surrogate mother may not relinquish her parental rights under existing laws--even though she may want to.

Jefferson County Circuit Court Judge Jack E. Mudd refused to allow the mother to terminate her rights, even though she and her husband, as well as the prospective parents of her child, were in agreement.

Last night, Mudd said he made his decision to draw attention to the fact that there is "no law in Kentucky dealing with surrogate parenting. Someone had to stop and take a look. We have a case in New Jersey or Michigan where a surrogate mother gave birth and they found that the donor was not the father . . . this thing is mushrooming."

Although Mudd, who is running for reelection this year, said the baby girl still is the legal offspring of the surrogate mother and her husband, the ruling is expected to have no practical effect because the biological father already has the newborn child with him in another state.

The ruling adds to the already murky legal status of surrogate mothering, which has gained popularity in the last few years. It was first undertaken in Kentucky in 1979.

Mudd said the Kentucky law that allows a woman to relinquish her parental rights was designed to transfer custody to a "licensed child-placement agency" rather than an individual.

Presently, Kentucky law requires that adoptions occur only when the state has interviewed the prospective parents and declared them suitable. In this case, which concerns a woman who was artificially inseminated for a couple who live in another state, no such permission was granted.

Although Kentucky has no laws relating specifically to surrogate mothers, in nearly 40 other cases in the state the procedure has been that the surrogate mother relinquishes her parental rights and the father whose sperm was used to impregnate her affirms his paternity. The father then assumes custody with his wife, who adopts the baby.

However, in this case the judge also said that paternity must be determined by blood tests, not just an affidavit from the father acknowledging paternity, as was provided.

"The donor is coming in and seeking to do something that's not provided for under the law," said Mudd.

The surrogate mother's husband also provided an affidavit stating that he had had a vasectomy and was sterile. None of the four parties has been identified, nor were their attorneys, and the records are sealed.

Asked if he was aware of any objections to surrogate parenting among his constituents, Mudd said that he "didn't deal with it on moral grounds," and that he was "forbidding something because it didn't meet law requirements."

"I don't know what it is the judge wants to have happen," said Dr. Richard Levin, whose Surrogate Parenting Associates Inc. arranged the match.