Contrary to conventional wisdom, many women who have had a cesarean section delivery can safely give birth without surgery the second time, according to the leading organization of childbirth physicians.

The American College of Obstetricians and Gynecologists will advise its members early next month of a special set of guidelines for selecting women who need not have a repeat cesarean delivery.

After a detailed review of studies of more than 28,000 women who successfully had vaginal deliveries following cesareans, the college's committee on obstetrics concluded that "under proper conditions, many women who have had a cesarean birth may safely be considered for vaginal delivery," said Dr. Robert Cefalo.

If followed, the new policy could have a major impact not only on women, but also on health care costs. Although the death rate from cesareans is low, it is greater than that for vaginal deliveries and there are additional health risks in any major surgery. A cesarean also involves higher doctors' fees and longer hospital stays.

In 1980, nearly 600,000 babies--16.5 percent of all deliveries--were born by cesarean section, with as many as 150,000 of these repeat operations. Following a physician's 1916 pronouncement of "once a cesarean, always a cesarean," 99 percent of women today continue to have repeat surgeries.

But studies show that over half of women with the now-common horizontal incision in the lower uterus could be candidates for a subsequent normal delivery.

The ACOG policy follows a 1980 National Institutes of Health conference that concluded women should be given the option of vaginal delivery after a cesarean.

The new guidelines suggest that a vaginal attempt should only be made in properly equipped hospitals that could perform an emergency cesarean if necessary. There must be no known medical reason requiring a repeat operation and the patient must be carefully monitored throughout labor. The baby should be presenting head-first and weigh less than 8.8 pounds, ACOG said.