President Reagan's twisting of facts, figures and anecdotes has been variously attributed to misstatement, poor staff work, and any number of other excuses to protect him, and the American public has been remarkably tolerant of it. This time, however, his imagination has soared to eye-opening new heights.

Speaking to a meeting of religion editors about the abortion legislation in Congress, the president said on Tuesday that he believes unborn children are "living human beings." To bolster his argument he said:

"I think the fact that children have been prematurely born even down to the three-month stage and have lived to, the record shows, to grow up and be normal human beings, that ought to be enough for all of us."

Before the day was out, the "record" the president leaned on fell apart beneath the weight of trying to make a fact out of something every American woman who has ever been pregnant knows to be impossible. At three months, most women aren't even in maternity clothes, much less delivering babies capable of independent life. Even at the end of three months, fetuses are only three and a half inches long or less, according to the American College of Obstetricians and Gynecologists.

After the president gave his latest citation from the Reagan Book of World Records, reporters began what is now becoming a routine: They called the White House press office to find out where he got his information, so that they could determine if it was true or not. According to an Associated Press story, a White House spokesman said he would check, and then later said the president was thinking of a single case involving a 4 1/2-month fetus that had survived. "He knew," the AP quoted the spokesman as saying, "but he said three instead of 4 1/2."

The White House would have the public believe that the affable president was once again the victim of a case of "misspeak." But the AP pursued the tangled web and found out that it led to something worse than misspeak. It turns out that this 4 1/2-month-old fetus that survived came to the White House's attention after the president's meeting with religion editors. It came to the White House's attention after reporters started calling the press office and after Morton Blackwell, special assistant to the president for religious groups, called Jack C. Willke, president of the National Right to Life Committee, trying to find out if any three-month fetuses had ever survived. To the credit of Dr. Willke, this was not a case of where one lies and the other swears to it. Willke said no. He then told Blackwell about a Cincinnati boy born in 1972 and weighing one pound, 10 ounces, about 19 weeks and 6 days after the mother's last menstrual period.

The American College of Obstetricians and Gynecologists, in the brief it filed at the Supreme Court in connection with the Akron antiabortion ordinance, states that there is no "unambiguous documentation" proving that an "infant weighing less than 601 grams at a gestational age of 24 weeks or less has ever survived." A spokeswoman for ACOG said the mother's last menstrual period is not always an accurate measure of when she became pregnant, since bleeding or spotting can continue afterwards. She said that doctors there, upon learning the birth weight of the Cincinnati boy, -- 1 pound 10 ounces or 754 grams -- calculated that it had reached a gestational age of 26 to 27 weeks.

President Reagan has played fast and loose with facts ever since entering the White House. But never have American women, who have been going through a sort of mass invasion of their privacy by the right wing, had to hear the president bolster his arguments for banning abortions with something as ludicrous as claiming that fetuses have survived at three months of gestational age. His ignorance of human reproductivity is as breathtaking as his nerve to weigh into a debate involving the welfare of millions of women with a fabrication.

American women have traditionally been entrusted with protecting the morals of their community and teaching the nation's young the kinds of values we hear so much about from the right wing. One of the teachings mothers pass on to their young is the value of education. Another is the value of telling the truth. We could use more of those old-fashioned values in politics now, and the White House is the place to start.