Anesthetics and pain-killers given to women during childbirth sometimes have long-lasting and adverse behavioral and muscular effects on children, according to a new federal report.

Doctors and mothers should be more cautious about using such drugs, and doctors should discuss their effects with women before their time of labor, said Dr. Sarah H. Broman of the National Institute of Neurological and Communicative Disorders and Stroke.

In a seven-year study of 3,528 infants, Broman and Dr. Yvonne Brackbill of the University of Florida found that for up to a year after birth, many children of mothers who took drugs were slow to sit up, stand and walk.

Other results, including some not yet published, show that at age 7 some of these children have behavioral problems and lag in language and learning skills such as speech, reading, perception, memory and judgment.

It is commonly believed that fewer drugs currently are being used in childbirth because "natural birth" has become so popular.

However, the use of drugs is increasing during labor and delivery and also increasing during the months of pregnancy, Drs. Brack-bill and Broman reported.

In 1974, anesthesia was used in 95 percent of the deliveries in 18 large teaching hospitals, the two researchers said.

According to their report, pregnant women studied in Houston in 1973 took or were given an average of 10 drugs during pregnancy and childbirth. But in 1977 the average had risen to 15 drugs.

Yet "women have little voice in deciding which if any drugs they will consume." the researchers comment.

They quote favorably a recent report by an American Academy of Pediatrics Committee which said:

"... Until further studies are available, it would be advisable to avoid the use of drugs or drug dosages that are known to produce significant changes in neurobehavior of the infant.

"This statement does not mean that the patient in labor should be denied reasonable relief of pain by analgesic or anesthetic agents, but rather that the minimum effective dose of these agents should be administered when indicated.

"Moreover... the physician [should] discuss with the patient, whenever possible before the onset of labor, the potential benefits and side effects of maternal analgesia and anesthesia on both the mother and the infant."

The Brackhill-Broman report was distributed by the National Institutes of Health yesterday in response to a Freedom of Information Act request by United Press International. Dr. Donald Tower, head of the neurological disease institute, called the release "premature," since "the report has not had a thorough review yet."

But he said the results confirm those of many smaller studies, usually of infants in the first weeks of life. Tower called the American Academy of Pediatrics Committee recommendation "reasonable" in view of current knowledge.

"We did not see any severe motor effects, any severe disability," Broman said yesterday. "The motor effects we saw were generally very subtle. But even subtle effects mean something is going on."

She would not disclose the detailed behavioral effects found in the last examination of the children at age 7. But Brackbill has said that at this age, the affected children showed an average IQ deficit of four points.

Injuected pain-killers had the mildest effects. In some cases, the effects disappeared after four months or 12 months, the psychologists said. Inhaled anesthetics generally had the greatest effects, although some of the most marked effects occurred when the mother received two drugs, a pain-killer in combination with an anesthetic.

All three inhaled anesthetics studied -- nitrous oxide, ether and Trilene -- had similar effects. But among the pain-killers, scopolamine (trade name: Hyoscine) had the greatest effect. Promazine (Sparine) and secobarbital (Seconal) had the next greatest effects and oxytocin, promethazine (Phenergan) and meperidine (Demerol) had the least effects.

If a mother got a drug, more than half the babies studied showed at least one adverse effect, although in many cases a slight one, Broman said. But for any single adverse test result of motor skills like sitting and standing an effect was usually found in no more than one baby in five or 10, depending on the agent.

The researchers urged more study of the drug effects, and just how doctors should go about involving mothers in drug decisions.