Q. "When you're pregnant you look around and it seems like everyone is pregnant and when you have a baby, all you see are babies," writes a mother from Brookland in Northeast Washinton.

"Well, we have a retarded child, and now it seems as if retarded children are everywhere. Our Billy is 5, going on 2, and there are three retarded children -- that I know about -- within a few blocks of our house. The latest was born a few weeks ago with Down's syndorme I can give the mother some comfort and some advice, but I'd like to know if there are any new services and I'd also like to know what is available for my son." A. You're a good lady to be concerned about your neighbor when you have such concerns of your own, but you know the importance of parent-to-parent help. Nothing has been as neglected in the field of retardation as the effect it has on the family. It's hard enough for a group of people to live together, but to live with a handicap, whether it's mental or physical, multiplies every problem many times.

Your friend not only needs any parents' support group she can find, but her baby needs to be in an infant-stimulation program too. They're available at Howard, Georgetown, the D.C. Society for Crippled Children and at D.C. General, which has the excellent Handicapped Infant Program where everyone in the family is taught how to help the child and each other.

Your neighbor also will profit by the book "Teaching Your Down's Syndrome Infant" by Marci J. Hanson (University Park Press, Baltimore).

Retarded or normal, the more stimulation a baby gets, the smarter he's going to be and the easier to care for.

There are two good free workshops this month too, open to all parents in the metropolitan area whose children are handicapped in any way.

There will be experts at both conferences to explain the two fairly new laws that give all handicapped people between 3 and 21 the right to free, appropriate education, including physical education, and in as unrestricted a setting as possible. This is what mainstreaming is all about.

To get this placement, the law calls for the teacher and the parents to meet together once a year for a critical evaluation of the child. Here they examine the tests and records and decide the program that would be best for him for the next 12 months, including such extras as music and movement. The plan must be written in the language the parents speak at home and they must agree to it, too, and in writing.

However, since life is seldom lived the way the law requires, the leaders at both conferences will tell parents how to get an independent hearing if they feel shut out of the evaluation or if their child is denied the testing or placement they want.

The first conference to help parents of the handicapped will be held Saturday, May 10, from 9:30 a.m.-2 p.m. -- at the School of Nursing, Catholic University, 4th Street and Michigan Avenue NE. There will be a free lunch and also free sitters, trained to care for both normal and exceptional children. To reserve space, call 635-5800.

The C.U. conference also will have a workshop to help parents find out their child's strengths, so the mainstreaming teacher can build on them. Other sessions will talk about the way federal and local governments work together and what you can do to make them work better; how to get parents more involved in the school -- whether the principal likes it or not -- and how a handicapped child affects a family, particularly brothers and sisters.

The second conference, sponsored by the Parent Educational Advocacy Training Center, will be held May 16-18 at St. Paul's Episcopal Church, 228 S. Pitt St., Alexandria.

At this meeting leaders will describe the educational, psychological and medical testing a child is given for special placement, as well as the social-cultural evaluation. Parents will be taught how to monitor their child's progress and how to organize this information for the professionals, so any meetings with them will be less emotional.

The PEATC, founded by parents of handicapped children, gives these conferences quite often and they also give individual consultations, for $25 an hour or less, depending on income.

The Information Center Handicapped Individuals, Inc., is another fine source. It is located at 120 C St. NW, and is a nonprofit, area-wide group and the official consumer representative for the handicapped in the District.

This center publishes the definitive Directory of Services for Handicapping Conditions, which every library in the area carries. It also publishes Here Comes the Sun, an annual directory of summer programs for the handicapped (free if you call them at 347-4986).

A third Information Center publication, Access Washington, is a guide to every public building in the area, reporting ramps, elevators and number of steps, size of lavatory stalls and any other information a restricted person needs before he goes there. Access Washington costs $1, plus 48 cents for postage.

You also are sure to get some good advice from MARC -- the Montgomery County Assn. for Retarded Citizens (949-1454) and Closer Look (833-4160), which will send you data about any handicap you specify, whether you want to know about retardation, diabetes, Tay-Sachs, schizophrenia, cancer or dyslexia, and the support groups both nationally and for whatever state you live in.

In your case, Closer Look will send you the best step-by-step instructions we've seen to help District parents of the handicapped deal with the school system: the May 1978 bulletin of the D.C. Citizens for Better Public Education. Inc.