Last month, the physicians at Columbia Hospital for Women voted not to extend delivery room privileges to certified midwives. This is the second time in the past two years that physicians at Washington hospitals have voted to keep out midwives, and while the reasons offered vary, there can be no argument that the net result has been to diminish competition to obstetricians and to limit the childbirth choices of prospective parents in the Washington area.

What has happened here is not unique. According to Federal Trade Commissioner Patricia Bailey, the FTC is looking "at a number of cases" in which nurse-midwives have been denied hospital privileges. This is no small matter, either for the obstetricians facing declining birthrates or for parents facing increasing health-care costs. Nurse-midwives spend considerably more time with their patients and charge considerably less than do obstetricians. When physicians deny them hospital privileges, it limits their practice to home births, which many parents are reluctant to risk.

The FTC's interest in midwives is only one example of the agency's increased interest in health care. The FTC has also prohibited the American Medical Association and the American Dental Association from banning advertising by doctors and dentists, and it has challenged physician boycotts of Medicaid and of cost-cutting health maintenance organizations.

The upshot of the FTC's activities has been a well-financed drive in Congress to take away all of its jurisdiction over the commercial activities of the professions. The political action committees of the AMA and the ADA have given almost $2.5 million to members of the House since the last election, according to Congress Watch, a group that monitors campaign contributions. Some 72 percent of that largess went to 219 members who cosponsored the bill to limit the FTC, and 84 percent of those got donations of $10,000 of more. (Rep. Frank Wolfe (R-Va.) has been the biggest recipient, according to Congress Watch, with donations totaling $24,000. Rep. Stan Parris (R-Va.) has received $17,000.)

Rep. Albert Gore (D-Tenn.), who two years ago held hearings on the denial of hospital privileges to nurse-midwives, says the legislation amounts to a congressional sanction of restraint of trade against such groups as midwives. "The issue is whether or not parents who wish to employ a certified nurse-midwife can utilize her services within a hospital environment or whether they will be prevented from doing so by a more powerful profession which resents the competition."

The AMA contends that the FTC has never had jurisdiction over it and that FTC activities in the health field have not been in the public interest. The legislation to strip the FTC of jurisdiction over the professions has been reported out of the Senate Commerce Committee, but an attempt to get it passed before the Senate recessed was defeated.

A bipartisan effort led by ranking members of the House Energy and Commerce Committee has resulted in a compromise bill that makes it clear that the FTC is not in the business of licensing professionals while preserving its jurisdiction in any activities that appear to limit trade.

The compromise is being supported by an extraordinary coalition that includes midwives, the elderly, nurses, chiropractors, psychologists, optical chains and the Washington Business Group on Health, which represents the top half of the "Fortune 500" companies that are concerned, as employers insuring millions of workers, about rising health-care costs. The Reagan administration is also supporting it.

Americans paid $287 billion for health-care costs last year. Rising costs and their enormous impact on American households have made health care a principal target for FTC inquiries. The movement to open up the lucrative medical professions to such competition as provided by midwives can only help consumers. Efforts to limit the FTC can only hurt them.

And when all is said and done, there will be two important lessons for consumers and voters: One is how the elite professions, faced with challenges in the marketplace, fought back by trying to buy protective legislation from Congress. And the other will be how Congress, afloat in political contributions from these professions, reacts.