On a recent rainy weekday night, nine strange -- Six women and three men -- gathered in the recreation room of a Silver Spring home to discuss an irreversible personal decision that could be the single most significant and difficult choice of their lives.

"I never thought I wanted kids," began a 31-year-old editor. "But recently I've been haunted by baby hunger."

"Everyone says it changes your life," said a 38-year-old personnel officer. "My wife and I are very happy, and part of me wants to keep things as they are. But part of me hates to miss out on a major life experience."

"Frankly, I'm scared," confessed a 35-year-old single biologist. "I want to have a family, but time is running out. I've met very few single men who want children. Some of my single girlfriends have been talking about having kids without marriage, and it's an idea I want to explore."

"I just got married," said a 37-year-old Virginia school administrator. "Financially we can afford either a sailboat or a kid. Right now, I'd prefer the boat."

At any other time or place in history, a group like this "Thinking About a Baby?" workshop would be unheard of. Even ludicrous. Pregnancy was a given, and children were considered essential for their social, emotional and labor contributions to the family.

But today, technology has made children a choice, and the economic structure has made them a financial drain, transforming the once taken-for-granted fact of life into a more deliberate and conscious decision.

"These days the question is not how many children to have," says California psychologist Diane Elvenstar, "but whether or not to have any at all."

Over the last few years Elvenstar has helped more than 400 couples make the parenthood decision--for $175 per couple -- through her "Children: To Have or Have Not" workshops. She authored a recent book by the same title, which she calls "a guide to making and living with the decision."

Elvenstar's is one of many "baby-maybe" books and courses designed to help couples grappling with the parenthood option. Over the last decade, books like Why Children? and Up Against the Clock have become commonplace, and classes for child-pondering couples have sprung up around the country.

Elvenstar's book includes instructions on how to set up a decision-making workshop in the community. Editorial consultant Leslie Braunstein, 31, created her own "Thinking About a Baby?" workshop last year -- offered through Washington's Open University -- because she and her husband "would have liked more information when we were trying to decide about children." The most popular course at New York's "Network for Learning" is "Pregnancy After 30," which company administrators say always draws 250 or more.

One reason for the wide-spread interest is that the baby boomers have come of age as potential baby makers, notes Patricia Ionides, director of social services at Columbia Hospital for Women. "You've got an awful lot of soul-searching couples who grew up in the '50s, living in a time when the family system has changed dramatically. People are very mobile and tend not to live near their extended families, which traditionally were a great support.

"The majority of women are employed and have to decide whether they can afford--financially or careerwise -- to take time off work. There are so many options today. Can the father take time off, do they want their child raised by a caretaker? It can complicate the decision."

The reason many couples are reading books and taking courses to help them make their decision, says Ionides, "is that it gives them a sense of control. There are lots of unknowns about having a child. It's a risk. For more educated couples, the idea of losing control can be very upsetting."

Adding to the complexity of the decision are medical advances such as amniocentesis -- a test to detect Down's Syndrome, more prevalent in mothers 35 and over, and some other birth defects -- which have reassured women that they can wait until after they reach age 30 to have children. Since 1970, the proportion of first births to women aged 30 to 34 has doubled, according to Planned Parenthood. The Bureau of Census estimates that between 1980 and 1990 the number of women over 35 having children will increase by 46 percent.

Nearly 17 percent of all first births in the Washington Metropolitan area in 1980 were to mothers over 30. Montgomery County led the area with 23 percent, followed by Northern Virginia with 19 percent, the District with 14 percent and Prince George's County with 12 percent.

Men are also delaying fatherhood, according to an American Psychological Association report which says, "Fathers are taking on an increased share of the daily duties and responsibilities of child care. The likelihood that their perceived roles will be sharply altered has prompted growing numbers of men to delay fatherhood, many until their early thirties."

[Recently, many couples who were deliberately planning to have children after 30 pushed the panic button when a February issue of the New England Journal of Medicine reported on a French study that found a sharp decline in female fertility between the ages of 31 to 35. Since then, the report has come under attack from several sources, largely because it failed to stress that the study was of women who were being artificially inseminated -- a procedure that is less successful than natural insemination in achieving conception.]

Although "everyone faces a unique set of circumstances," says 31-year-old psychologist Elvenstar (who has decided "for now" not to have a child), couples fall typically into three categories: "now-or-never couples" who hear the biological time clock and feel pressure to decide soon; "conflicted couples," where one partner wants a child and one doesn't; and "planners" who "know in their heart of hearts what they really want to do" but want reassurance that they're making the right choice.

But for those couples trying to make the parenthood decision, Braunstein (who has a 17-month old son) offered this advice to participants in her workshop: "If you're looking for rational reasons to have a child, it's hard. Who wouldn't want $200,000? People have children for irrational reasons. Like love."