In his criticism of President Reagan's proposal to eliminate government funding of abortions in the District of Columbia, Courtland Milloy {Metro, Aug. 4} states that banning abortion cannot teach young single people what families, schools and churches have failed to teach (not to have sexual relations).

Thirty years ago, when abortion was illegal, many teen-age girls would not engage in intercourse because they did not want to become pregnant. Regardless of morality, they knew that if they became pregnant, they would have to bring a new life into the world and care for it. Their boyfriends were also aware that there was "no way out."

I certainly am not suggesting that stopping government funding of abortions will eliminate unwanted pregnancies among the poor. But, as a public school administrator, I know that poor teen-age girls, like their more affluent peers, are able to make judgments of the obvious practical consequences of their actions. Denying public funding of abortion, in my opinion, would serve as a motivating factor for at least some of our young, single people to refrain from sexual relations. FRANK E. BARTOS Upper Marlboro Courtland Milloy's attack on President Reagan because of his stand on abortion funding in Washington points out one of the main reasons little babies are dying at the rate of 4,000 per day in the United States: ignorance.

One of the reasons ''boys and girls are hot to trot'' is because they know that, if they get in ''trouble," one of the ways they can get out of it is abortion. In other words: no accountability for your actions. Take that option away and the pregnancy rate will go down.

Instead of giving boys and girls the easy way out, why not make them think twice by taking away the abortion option? And while you're at it, just watch the pregnancy rate drop when states pass and enforce laws making the man financially responsible for his actions. ''All play and no pay'' seems to be the watchword among today's men. If Courtland Milloy and others would write about ''paying the piper'' instead of ''freedom of choice,'' we would all be better off.

WILLIAM J. SCHUHL President, Bowie/Crofton Right to Life Bowie