For the first time in the emotion-charged mine field of the abortion rights controversy, representatives of both sides met yesterday in a five-hour session they described as "productive and amicable."

The results were narrow and tentative. All they really agreed on was that there is a need for more education on the reproductive process and that they should meet again April 19. They also agreed not to discuss the issue that has divided them bitterly -- abortion itself.

But the fact that about 60 represent-atives from 30 groups -- 10 "pro-life" and 20 "pro-choice" -- met to "begin a dialogue" was termed "a giant step forward" by Eleanor Smeal, president of the National Organization for Women.

As she and other leaders of each side were describing the dialogue at a news conference, three members of a pro-life group came up behind them and displayed two female fetuses that they said were "killed Monday morning by abortion."

Nancy Hackle of Cleveland, who spoke for a group called PEACE, People Expressing a Concern for Everyone, said the group had planned the disruption, even though some of its members had taken part in the fivehour meeting, because "the vital issue is life. We can't talk about anything else until the time comes when no babies are killed."

She said the fetuses, one of 18 weeks and the other of 5 1/2 months, were "young and poor and black."

As they were held in a large, blue handkerchief, several pro-life participants in the meeting began to cry.

Some pro-life participants went to where the leaders of the session were seated to denounce the disruption.

One pro-lifer, Mary B. Stout of St. Louis, president of an anti-abortion group called Life and Equality, said, "We came to this meeting because we wanted a constructive dialogue. We totally reject the use of violent and disrespectful methods of confrontation such as we have just witnessed here."

Julie Loesch of PAX Center, in Erie, Pa., called the display of the fetuses "inappropriate" and "an offense against the spirit of dialogue, which we intend to carry back to our neighborhoods in the spirit of common humanity."

Another pro-life advocate, Elizabeth Moore of Feminists for Life of America, said with reddened eyes and faltering voice, "We made a commitment to get to know each other. This has been a very fair, impartial and honest meeting.

"I am very much ashamed of any tactics which tend to disrupt the mutual respect we have for each other."

After the PEACE disruption, the news conference continued and Smeal said the incident was "not in the mainstream of our meeting. This happened because it was a way to get your attention. The bottom line is that the purpose of the meeting was to look for ways to reduce incidents of unwanted pregnancies and to reduce polarization of the issues."

Afterward she said she was not discouraged and that the "dialogue" would continue to see if the two sides could reach a "commonality on such things as reproductive health, fertility and family planning."

Participants acknowledged that two of the largest pro-life groups, the National Right to Life Committee and March for Life, declined to take part.

After Smeal issued the invitation to both sides Jan. 22, Nellie Gray, who heads March for Life, commented acidly, "I do not negotiate with baby-killers."