Under White House pressure not to weaken the legal underpinnings of the so-called "Baby Doe" rule, the Justice Department has perfunctorily reiterated its argument that a Dallas hospital that receives Medicare and Medicaid funds should be investigated for allegedly violating a deaf patient's civil rights.

But on another point, William Bradford Reynolds, assistant attorney general, aligned himself with attorneys for Baylor University Medical Center, arguing that the investigation should be limited to the specific hospital programs that receive the $30 million in funds.

In a brief filed late Tuesday in U.S. District Court in Dallas, Reynolds was forced to take a position that runs counter to his efforts to restrict the reach of a variety of civil rights laws designed to protect minorities, women and the disabled.

The opposite position would have undermined the government's arguments in support of the controversial "Baby Doe" rule, which President Reagan strongly endorses. That rule and the Baylor investigation had the same legal justification: that hospitals' receipt of Medicare and Medicaid assistance forces them to follow the federal law prohibiting discrimination against the handicapped.

The "Baby Doe" rule, before it was overturned by a U.S. District Court judge on procedural grounds, required hospitals to give care and medical treatment to disabled infants. To encourage reporting of alleged violations, hospitals had to post notice of a "hotline" number for anonymous complaints to the Health and Human Services Department.

Justice entered the Baylor case in 1982, when HHS asked it to force Baylor to allow HHS officials to investigate the deaf patient's discrimination complaint. The patient, according to Justice, said she was denied access to a sign language interpreter hired at her expense.

HHS asked, and Justice agreed, to sue the medical center to gain access to records and other information about the complaint.

Baylor attorneys argued the hospital didn't have to cooperate with HHS, since Medicaid and Medicare payments represent "contracts of insurance," not direct financial assistance. If Baylor receives no direct assistance, it argued, it cannot be investigated for the alleged rights violation.

Baylor lawyers dispute Justice's version of events, but would not be specific yesterday. Earlier this year, Baylor asked the court to rule on its behalf without a trial. It was this motion that Justice opposed Tuesday.

Internal Justice Department documents show that Reynolds asked his staff earlier this year to find a legal rationale to back off Justice's original position and redefine Medicare and Medicaid as something other than "federal financial assistance."

However, when Reynolds took his arguments to a White House meeting attended by presidential counselor Edwin Meese III, he was rebuffed. Others present argued that bailing out of the Baylor case would endanger attempts to draft a new "Baby Doe" rule, according to a source who was at the meeting.