Many American teaching hospitals were continuing to sterilize underaged Medicaid patients this year even though the government declared a moratorium on the practice in 1973, according to a survey released yesterday by Ralph Nader's Health Research Group.

A survey of the nation's 350 hospitals with approved obstetrics-gynecology teaching programs revealed that at least 52 of them continued through this year to sterilize indigent women under the age of 21.

The Department of Health Education and Welfare forbade Medicaid reimbursal for such sterilizations in August 1973, following publicity about sterilizations of young indigent women without informed consent.

Other violations found to be occurring in the 23 hospitals that responded to the survey included the obtaining of consent for sterilization from women in labor and the failure to inform patients orally that they would not lose their right to welfare benefits if they refused to be sterilized.

Among hospitals in the Washington area, only one of the eight surveyed responded to the Health Research Group questionaire. That hospital, Prince George's General Hospital in Cheverly, was one of those performing Medicaid-funded sterilizations on patients under 21.

A stricter set of guidelines governing Medicaid-funded sterilizations was released in February 1979 and area hospitals contacted yesterday - including Prince George's - said they now observe the age limit of 21 for Medicaid patients, though some still perform sterilizations on private patients under 21 for the purposes of family planning.

Prince George's General Hospital stopped sterilizations of Medicaid patients under 21 in May this year, according to Raleigh Cline, the hospital's chief executive officer. However, a private patient over 18 who says she wants no more children may be sterilized, provided she and her physician complete informed consent forms, Cline said.

The age limit for Medicaid patients was labeled "restrictive and unfair" by Dr. Allen B. Weingold, chairman of the department of obstetrics and gynecology at George Washington University Hospital. Weingold said the age limit is being observed at George Washington, but that it caused health risks for some Medicaid patients, who would be forced to use contraceptive methods that might be dangerous to them because they could not be steri-sterilized. Weingold said he might favor sterilization for "a 19-year-old who has has four children and would like to retire from the field" rather than use contraception, though he would be uncomfortable sterilizing a woman of the same age who had had no children.

Some states have continued to use U.S. Medicaid funds to pay for sterilization of women under 21, though federal officials only recently have begun to compile statistics of how many such sterilizations have been funded, according to Pat Schoeni, director of public affairs for the Health Care Financing Administration, which administers Medicaid.

Schoeni said it is up to the states to inform hospitals of regulations, but that if a hospital wrongly receives federal funds for sterilizations, the error can only be corrected through government audits, which may take a year or more.

Reacting to the Health Research Group's findings, HEW Secretary Josph Califano said he was "deeply disturbed" by the allegation that major teaching hospitals that perform sterilizations on Medicaid patients have failed to adopt HEW requirements for informed consent.

Noting that compliance may have improved since release of the 1979 regulations, Califano said he would urge rapid completion of an audit, begun last month' of states that account for over 50 percent of federally funded sterilizations.