My son has recently begun running around with some tough kids who have introduced him to marijuana. He doesn’t deny what he is doing because he says it is harmless. Can you give me the facts?

Your son has been given some very bad information that is being passed around by those who are promoting the legalization of marijuana. It is a lie. Dr. Harold Voth, the senior psychiatrist for the Menninger Foundation in Topeka, has set the record straight.

He said, first, that five marijuana cigarettes have the same cancer-causing capacity as 112 conventional cigarettes. Second, the part of the brain that allows a person to focus, concentrate, create, learn and conceptualize at an advanced level is still growing during the teen-age years. Continuous use of marijuana over a period of time will retard the normal growth of those brain cells.

Third, a study conducted at Columbia University revealed that female marijuana smokers suffer a sharp increase in damage to DNA, the genetic code. It also was found that reproductive eggs are especially vulnerable to damage by marijuana. Fourth, a second Columbia University study found that people who smoked a single marijuana cigarette every other day for one year had a white blood cell count that was 39 percent lower than normal, thus damaging the immune system and making the user far more susceptible to infection and sickness. Smoking marijuana is a dangerous hobby.

I doubt if your son will be satisfied with this answer, even though you should share it with him. His motivation is probably related more to peer pressure than to his belief in the harmlessness of marijuana. The danger is that he will “graduate” from pot to something harder and more addictive. If I were you, I would bring all my energies to bear on getting my son away from the gang he is now running with, even if it required us to move. He is apparently at a critical juncture in his life.

I just found out that I’m pregnant. When the doctor told me, he warned me not to drink anything with alcohol in it until the child is born. I’m used to having a few beers after work and I like a cocktail several times a week. Is it really necessary for me to give up all alcohol until my baby arrives?

I urge you to heed the advice of your physician. That precious baby inside of you could be severely damaged if you continue to drink in the next few months. Your child could have what is known as fetal alcohol syndrome, which can cause heart anomalies, central nervous system dysfunction, head and facial abnormalities and lifelong behavior problems.

Fetal alcohol syndrome also is thought to be the leading cause of mental retardation. It is a terrible thing to inflict on a child. Babies can be harmed by alcohol in the blood of the mother at any time throughout gestation, but they are especially vulnerable during the first trimester. That’s why you should not drink during the remaining seven months of your pregnancy, but by all means, don’t swallow a drop of alcohol right now.

You may remember the story of Samson in the Old Testament who terrorized his enemies, the Philistines. Before he was born, an angel told his mother that her child was destined for greatness, and that she must not weaken him by imbibing strong drink while she was pregnant. Medical science has now verified the wisdom of that advice. That’s why a similar warning to pregnant women is posted by law wherever liquor, beer or wine is sold.

For you, and for all pregnant women and those who anticipate becoming pregnant: Don’t take chances with your baby’s future. There is no level of alcohol that is known to be safe. Abstain for the entire nine months. You and your baby will be glad you did.

James Dobson is president of the nonprofit organization Focus on the Family, P.O. Box 444, Colorado Springs, Colo. 80903; or www.family.org. Questions and answers are excerpted from “The Complete Marriage and Family Home Reference Guide,” published by Tyndale House.