Northern Virginia anti-abortion forces jammed a public hearing yesterday that was held to discuss whether Virginia should continue to pay for abortions for Medicaid recipients.

More than 85 speakers on both sides of the issue were heard at the day-long hearing in Alexandria, one of six conducted throughout Virginia by the state Board of Health. The hearings followed a tentative decision by the state board to pay for only those abortions necessary to insure the life of the mother.

Federal funding of most abortions for low-income women came to an end last summer, leaving the states the option of following the federal example or of continuing to pay for abortions solely with state funds.

Those who came to voice support for continuing state aid to low-income women for abortion contended that withdrawal of such funding amounted to discrimination against the poor and said that the economic and emotional burden of unwanted children was a much higher price to pay.

"The issue is inequality," said Margaret Davidson, associate director of Alexandria social services."How can we turn our backs on women because they are poor"

But while the supporters of state-funded abortions came armed with sheafs of statistics, case histories and socialogical studies, they were heavily outnumbered by those who came to bear personal witness to what they saw as the immorality of abortion no matter what the income bracket.

Most of those who came to testify in the bare, brightly lit hearing room were women, and both sides brandished their credentials as wives, mothers and taxpayers in upholding the correctness of their cause.

"I raised five children," said Marian Pape of Falls Church. "I was poor too. My husband was a mail carrier. I worked hard. But everything is free today. I come from a community of hard-working people, not college educated. But I look around and I want to know, where are all the little children? Who is going to help pay the taxes when you grow old?"

Speaking in favor of continued state support for abortion, however, Barbara Guinee, the mother of three children who speak yesterday for Planned Parenthood cited numerous facts about teen-age pregnancies. She cited the case of a 13-year-old who called her up and told her she was pregnant. "She'll probably have to drop out of school," Guinee said. "She would have to go to welfare. Why should anyone force this child to have another child? Because she made one mistake, let us not damn her forever."

To the portrait painted by Ghinee, however, Michelle Chasen, 18, rose in fierce rebuttal. "I am a teen-age unwed mother with two babies," Chasen testified. "How can you tell me what it's like?"

Chasen said she had her first child when she was 15. "They told me I would never amount to a dime," she said. But last March, Chasen said, she graduated from high school through the Arlington adult education program, and now, with a second child who is 8 months old, she is attending Northern Virginia Community College. "I will make it," she said, "with my two kids."

And so it continued on both sides, case histories and true confessions, the end of each five-minute speech greeted by determined applause from the appropriate side.

By midafternoon, however, the field was left for the most part to those opposed to abortion, some of whom had been called the night before by anti-abortion groups and asked to attend.

"There's more of them here because they're the underdog," said Joyce Sherman, who came to the public hearing to speak in favor of state-funded abortions. "But unless our side realizes what's at stake, they won't be for long."