THE FIRST TIME it happened was in a restaurant in Florida this winter when we were having dinner with a former editor and his wife. We had not seen them in a couple of years and you might think that would diminish the familiarity, but it did not. We sat, ordered a round of drinks, and then he popped the question: "You won't mind if I ask you this," he said, flashing a warm smile, "but was this child planned or unplanned?"

In the old days, the days Before the Pill, no one would have dared ask that question. It was considered rude. It was personal. It was what these days we might even call an invasion of privacy. Before the Pill and before the sexual revolution, what people did in the privacy of their bedroom, and when they did it, and how and why, were issues that stayed within the privacy of the bedroom. Now, of course, no one thinks twice about asking people about their sex life, their methods of contraception, or what they think about the latest sex manual on the bestseller list. Now we are ever so open and frank about sex. We don't have hangups about sex anymore. Now, we are enlightened.

There were, of course, often practical reasons that contributed to our past hangups. In the days before the Pill, you didn't dare ask people if a child was planned or not because there was every chance the child was not. Expectant mothers frequently led secret lives back then, smiling and radiant on the outside, while carrying an unplanned, inconvenient child on the inside.

There were exceptions. There was that whole exotic group of Catholic women who used a birth control method known as Vatican roulette. But there was the tacit understanding that Catholic women planned their children, all 12 of them, the day they joined the church. So you never asked Catholic women whether their babies were planned. You knew the answer.

And there were other expectant mothers who were simply curiosities. There were mothers who had six children, not because their birth control had failed them, but because they wanted a large family and had intentionally set out to have five or six children. And if they had a couple of extra, well that was okay, they always wanted a large family. And there were older women, women in their early 40's who got pregnant. They weren't having babies, though. They were having little surprises. Everyone likes surprises.

The point is that before the Pill and before the sexual revolution of the '60s, babies just came. Now, couples make decisions and no one seems to think there is the slightest thing wrong with asking women whether a baby is planned or not. And that's only the beginning of it.

If you say your baby is planned, the next question you can anticipate is: "How many more do you intend to have?" or: "When do you intend to have the next one?" Don't make the mistake of thinking people are merely engaging in polite conversation and showing a little interest in your family. Not at all. The questionnaire is laying the groundwork for the important question, which is when are you going to get your act together and remember Zero Population Growth?

That's if you're not working. If you are a working mother, there is another set of questions. What are you going to do about child care; how are you going to juggle family and your job, and don't you already have two children?The implication is that either your career or your children are going to suffer and in planning to have another baby you might well have taken leave of your senses.

And what happens if by some chance you are pregnant, and heaven forbid, the baby was not planned. Can you say that these days? Of course not. Say the baby is a surprise and people ask if you (a) can't use the Pill (b) wore an IUD that betrayed you, (c) are Catholic or (d) all of the above. The assumption is that anyone not trying desperately to have a child is desperately trying not to, and this means that an unplanned child is an unwanted child. And you can't possibly tell your friends or family that the child you are carrying is unwanted. That not only diminishes the child in the eyes of your family and friends, it diminishes you. It means you don't know how to plan your family, how to control your destiny. It means you don't know how to control your Reproductive Life. You are in the same league with the poor and the teen-agers and the illiterate.

It used to be that having children was something women simply did. We didn't have the option to choose, but then we didn't find ourselves forced to defend the choice. Now, a woman who decides not to have children will be asked about it at cocktail parties and dinners and she will be featured in women's magazines. It's not only terribly In o do, it's terribly In to discuss.

What's not In right now is having a large family. It used to be that having a lot of children was fun. If you wanted a large family you simply said, "I like children and I want a large family," and people believed you and left you alone. That was your business. Now, of course, having a large family is expensive and socially unacceptable. A woman who bears more than 1.8 children is going to raise eyebrows, particularly if she works outside the home.

And it used to be that having children was a private matter, something you discussed with your spouse and not your entire social set. Friends and colleagues understood that there were questions one simply didn't ask, some things that were personal, some aspects of human activity that should not be publicly examined, analyzed and discussed.

It used to be that people understood there are some things that are simply none of their business.