Q. Would you please explain the connection between pregnant women, cats and toxoplasmosis? A. Toxoplasma, a germ spread by cats, causes the disease toxoplasmosis. About one third of Americans have been infected with this parasite, but its chief danger occurs during pregnancy, when it can cause serious harm to the developing fetus.

About 3,300 babies with toxoplasmosis are born each year. Between one in 1,000 and one in 4,000 pregnant women develop this infection.

In adults, infection with toxoplasma usually doesn't produce any symptoms, and most people don't know they've had it. Occasionally, it causes swollen glands, sometimes with fever, headache and fatigue. Very rarely, toxoplasmosis leads to infection of the brain, inner eye or heart. Serious infections like those usually develop only in people with weakened immunity.

You get toxoplasmosis by eating toxoplasma eggs, called cysts, in either raw or undercooked meat, or by exposure to cat feces. Between 30 and 80 percent of domestic cats have been infected at one time or another. They pick it up by eating raw meat or infected prey.

If a woman develops toxoplasmosis while pregnant, she can pass it on to her unborn baby. Fortunately, this happens less than half the time. Most infected fetuses don't have any immediate problems, but about one in 10 are born with severe disease, including brain and inner eye infection, which can lead to mental retardation, seizures and blindness. Even though an infected newborn may appear normal, many will later develop brain and eye disorders.

To reduce your risk of getting toxoplasmosis while pregnant:

*Avoid contact with cats, especially those allowed to roam outdoors, or eat raw meat or wild prey, including mice.

*Avoid contact with cat feces and cat litter. If you have a cat at home, have someone else change the cat litter daily. This prevents toxoplasma eggs, if present, from ripening to an infectious stage, which takes two to three days.

*Wear gloves when working in soil or areas that may be contaminated with cat feces.

*Thoroughly cook meat until it changes color. The meat should reach about 150 degrees or hotter.

*Wash your hands after handling raw meat, soil or cats, and wash before eating.

*Q. My son had a seizure when he was 4 years old. He was treated first with phenobarbital and then Tegretol and has had no seizures since. When he was 14 a CAT scan showed he had an AV malformation in the brain. He had an operation to remove it and our neurologist said he was cured. That was three years ago. He's still taking Tegretol, and I'd like to know if he'll ever be able to stop taking it.

*A. There's a reasonable chance your son wouldn't have seizures off his medication, so I'd recommend discussing this with your neurologist.

Most of the research about stopping antiseizure medicine has been in children with epilepsy. Based on these studies, it's reasonable to make some educated guesses about your son's situation.

One researcher found that about 95 percent of certain children who hadn't had a seizure in four years remained seizure-free off medication. These children's seizures had been easy to contol initially, and the children had a relatively normal electroencephalogram (EEG, or brain wave test) at the time they stopped their medicine. Another researcher found that more than 75 percent of children who hadn't had a seizure in two years could safely stop taking medication.

In some instances, seizures may be more likely to come back. People who are mentally retarded or have other brain impairment, and those with difficult-to-control seizures, certain types of abnormal EEGs and certain types of seizures are in this category.

Because your son probably has some scar tissue on the brain, he may be more likely than children with epilepsy to have a seizure after stopping medication. But because he's done so well until now, chances are probably in his favor that he won't have a seizure. And now that he's of driving age, this might be a good time to see how he'll do.

Bear in mind that local motor vehicle departments require a medical report filled out by you and your physician stating your condition and medications. In Virginia, you generally need to be seizure free, with or without medication, for one year before being issued a license. In Maryland it's three months, and in the District one year.

You and your son will need to weigh the risks of having another seizure off medication (while driving, for example) against the risks of long-term therapy.

Follow-Up

At the end of my discussion about fibromyalgia [Nov. 27], a condition of painful muscles with tender "trigger" points, I referred interested readers to an article about the topic and listed an address for reprints. To my surprise, and that of the physician who wrote the article, the response was overwhelming. He's received more than 600 requests so far, with more letters still coming in.

Because he can't keep up with the demand, let me suggest another way to get hold of the article, and that's by looking it up at a local medical school library. There are three open to the public in Washington, at Georgetown, George Washington and Howard universities. I suggest you call to check their hours for public use.

The article is titled "Primary Fibromyalgia," by Dr. John L. Coulehan. It's in the September 1985 issue of American Family Physician, pages 170-177.