It is a documented fact that every time I find myself pregnant, the streets suddenly fill with women in the same condition. I always expect to hear that the population has increased enormously the moment one of my children arrives.

I offer the above by way of explanation . Somehow, now that I'm not pregnant, magazines, newspapers, and books are teeming with articles on why not to have kids, why you should raise an only child, and why various legal and civic organizations should contribute to the zero-ing of our population.

And there are certainly a number of good reasons to follow their advice. Many of these, working under the guise of zero-population growth, flaunt a king of international idealism, claiming that by cutting back or out on the number of children produced in your very home, you can somehow contribute to decrease (if that is possible) in worldwide population, thereby alleviating the plight of those crowded, starving masses in Inida and Africa and California.

Here is a bandwagon on which anyone can jump, for seldom is a justification so . . . well . . justified . We all know there are too many people in this world, the great bulk of whom are ahead of us in line at the grocery store and the movies. People, it is easy to see, are the root of every human problem, and an extra does of humanity seems no cure for society's ills.

Another good reason for not having kids is money, everyone's favorite woe. It turns out that children, taken in any amount, cost a lot of money to raise. i

Amounts vary, but it is doubtful that you can get away for under $20,000 a head, and if the kid should unthinkably decide to become a doctor, $100,000 becomes a plausible figure.

And what do you get in return for this astounding ivestment? Well, you get a grownup kid, commonly known as an adult.

Is he any good? Maybe.

Will he support you in your old age? Probably not: That is what retirement benefits are for.

Will he help out with the chores around the farm, and eventually run it for you? Again, maybe, but first you have to get a farm, which costs another $100,000 and is a lot of work for the money.

Will he confer honor and status on the family by becoming a big success or at least by marrying one? Don't hold your breath on this one: Few people are big successes any more, and those the world applauds, you probably wouldn't want in your family.

Zero-population growth and cost are just the surface reasons, though. I think it is time we exposed the real reason people have had against having children since time immemorial: Kids are a pain in the neck.

Kids are messey. Kids are noisy. Kids put toothpaste on your rug and ink on your tie. Kids wreck your car and run around with other kids who wreck other parents' cars.

Kids make a rotten first impression as babies. They cry an enormous amount of the time for obscure reasons. They have a faulty concept of time which does not include a decent night's sleep. Babies do all manner of natural acts which are neither beautiful nor charming, but wet. Babies, as well as kids, not to mention teen-agers, are destructive.

Kids rearrange your life style. People with kids have vinyl furniture and plastic drinking cups and toys in the bathtub and covers on their electric outlets. People with kids rarely go out alone because either they cannot find a babysitter or they cannot afford to pay him after paying for the evening out.

People with kids cannot be themselves, because kids -- an observant species -- repeat with amazing exactness every flaw of their parents. I'll never forget the day my 2-year-old daughter broke the non-plastic drinking glass I'd stupidly poured her fruit punch (not Hawaiina, possibly New Jersey) in, and said, cutely, "Oh, dammit!" Cut my conversation down by a third for the rest of the day.

So Why oh Why do we have them? What is there that would induce a fairly rational couple to set themselves up for all this?

Well, there's Mother Nature, a parent herself who apprently approves of the process. And there are various religions and philosophies that do not believe it is nice to fool Ms. Nature. Also, there are ignorance and stupidity -- qualities that are more creative than you would think.

But surely all of these do not account for all those people filling up all those highways in rush hour. What does, then? Now that science has proven what common sense has told us all along -- that children are no longer a sound investment, though they continue t be a hassle -- why does anyone bother?

I would hope we're not so progressive here that we cannot get away from Freud and his biological urges to talk openly and frankly about that world only the Recently Reborn dare to use And use and use and use) -- love. wDon't turn away; I promise not to use the term "meaningful relationship."p."

The reason people have children is to be able to love someone completely and unselfishly. They need it.

We all have formed loving attachment to various individuals, many of whom are now or once have been related to us by marriage or blood, and these attachments are based almost entirely on the give-and-take method. They start with the assumption that something is owed and something is owing from both parties involved -- a perfectly valid assumption. To love a man, a wife, a brother, a friend, you must be able to give love and you must be able to receive it. If not, it is a lopsided relationship, and good only for a folk ballad.

But a child, your child, owes you nothing, and you owe him everything -- his life, and all that goes with it. Having a child, then, is a lifetime lesson in giving, in reaching into you innermost recesses for all your talents, abilities, knowledge, patience, calmness, justice, humor and joy, and sharing these, using them to mold and buffer and bolster and protect and project your little human into society.

The point of having a child is no longer merely economic, or even cosmetic. The end product is no longer the ultimate reward, and occasionally is not a reward at all.

It is the process of being a parent which justifies the bearing of these individuals, and it is a process that can do more for you than sensitivity training or jogging ever claimed to be able to do. It can teach you more about yourself than perhaps you would care to know, force you to face up to any weaknesses that perhaps you would rather not face, develope any latent sense of creativity or responsibility you have managed to hide all these years, and drive you to despair, pride, ecstasy, and a thousand Scout meetings.

It also is a great excuse for baking cookies.