Lawsuits filed on behalf of seven children and their parents allege that the children were born without arms or legs or with other grave limb deformities because their mothers took Bendectin, the only government-approved drug for the "morning sickness" of early pregnancy.

Lawyers have been retained on behalf of seven more similarly deformed children and their parents.

The 14 cases of severe malformations open a new chapter in a continuing controversy about whether Bendectin taken in the first several weeks after conception has a cause-effect link to any of several birth defects, ranging from cleft palates to potentially fatal hernias.

The Food and Drug Administration is examining the cases but said late last week that no evidence to date establishes causal connections. The FDA's most relentless critic, the Public Citizen Health Research Group (HRG), and the manufacturer, Merrell Dow Pharmaceuticals Inc., took the same position.

"Because Bendectin is widely used in pregnancy about 20 percent of pregnant women have used it in the past , many abnormalities will occur in babies exposed to the drug, whether or not the drug caused them," the FDA said.

The FDA also renewed advice that Bendectin "should be used only when more conservative treatment of nausea and vomiting has failed."

In Cincinnati, a Merrell Dow spokesman said that each of the 14 cases "must be looked at individually. There are variations from case to case, and no two are alike. Such things as the type of defect, when Bendectin was taken, other drugs that may have been ingested, and genetic factors are among those that must be examined . . . . We still contend that the drug is the most tested drug for pregnant women, and the accumulated human studies continue to show a lack of association between use of Bendectin and an increase in birth defects."

Similarly, the FDA said that "two dozen studies involving exposures to Bendectin during pregnancy have not shown a link between it and limb-reduction defects."

The chief plaintiffs' lawyer, James G. Butler of Los Angeles, pointed out that the human studies have been faulted by the FDA's own medical officers. He urged FDA Commissioner Arthur Hull Hayes Jr. to halt sales of Bendectin.

Butler also cited a two-month-old federally funded study indicating that women in early pregnancy who swallowed the original Bendectin tablets may have quadrupled the risk of pyloric stenosis, a birth defect of the stomach that restricts an infant's ability to eat.

Butler is a long-time legal adversary of the company, having won a $2.75 million jury award against it in 1972 for a legless child whose mother had taken thalidomide, a sedative/tranquilizer that caused thousands of such severe injuries worldwide in the 1960s. Thalidomide was "tested" but not sold here.

Over the last two years, Butler said in an interview, lawyers around the country who knew of his thalidomide victory referred most of the 14 cases. He said he intends to seek compensatory and punitive damages for all of the children.

In addition, the U.S. District Court in Cincinnati is conducting pretrial proceedings in about 150 Bendectin cases in which various diverse birth defects are alleged.

Last week, the parents of the 14 children--nine boys and five girls ranging in age from 3 to 20--released photos showing the deformities and statements about their cases to the FDA and to The Washington Post. At the time, Butler was preparing for trial of one of the lawsuits, which may begin this week in U.S. District Court here.

The plaintiff, Anne E. Koller, 3, has no arms, no right leg and a severely deformed left leg. She was born at Walter Reed Army Medical Center here but now lives in Broken Arrow, Okla.

The company, formerly a unit of Richardson-Merrell, Inc., contends that "Bendectin has been used safely in over 31 million pregnancies," that "there has been no proof of any increase in the incidence of birth defects associated with its use," and that "there is no evidence that it caused Anne Koller's birth defects." In addition, a company spokesman said "there is a serious question when Mrs. Koller may have taken Bendectin."

The 14 children include a girl who is missing major portions of all four limbs. Six are armless: Anne Koller; a boy with shortened thigh bones; a boy with a severely deformed left leg, and Tawana Herring, 19, of Washington.

Matthew DeMeritt, 13, of Inglewood, Calif., born without legs, played "E.T." in the drunk scene in the movie of the same name, Butler said. Pauline Sand, 7, of Fairfield, Calif., has stubs for arms and no right leg. The company spokesman said there is "no record" that Pauline's mother took the drug.

For 20 years after Bendectin went on sale in 1956, it contained a now-abandoned anti-spasm compound, a vitamin, and an antihistamine called doxylamine succinate. Abroad, the company continues to sell the three-part mixture as Debendox, Lenotan and Meribental.

Two 1981 animal studies, called "preliminary and unconfirmed" in the current official Bendectin labeling, are cited in court papers filed by Butler. One showed a possible link between doxylamine and a potentially fatal hernia in rats; another found a hole in the heart wall of seven fetuses of monkeys given the current version of the drug, which combines doxylamine with a vitamin.

Butler also has filed animal studies indicating that doxylamine, as well as many other antihistamines and potent drugs, can damage the nerve which controls the development of an embryo's brain and spinal cord and can upset normal limb development. The studies go back to one published in 1950 by a famed University of California biologist.

"The damage increases with the size of the dose and can result in either injury or death to the nerve," Butler said. The evidence on doxylamine "points very strongly to the conclusion" that it causes birth defects in humans, he asserted.

The FDA rated Bendectin "effective" in 1976 after the anti-spasm compound was dropped, but had rated it "ineffective" at an earlier point. In 1981, HRG director Sidney M. Wolfe asked the government to halt sales of Bendectin on the ground that the vitamin ingredient decreases the effectiveness of the antihistamine. He also has charged that FDA files contain not a single study showing Bendectin to be effective as required by law.