All intrauterine devices, not just the discredited Dalkon Shield, can cause infection and infertility in a substantial number of the 2 million or more American women who use them, the Journal of the American Medical Association will report today.
The IUD is one of the most popular contraceptive methods among women who want continuous protection but want to avoid the potential problems associated with birth control pills.
However, the risk of pelvic inflammatory disease is nine times greater among current IUD users than among women who rely on other contraceptives, the AMA Journal article states.
Pelvic disease is a common cause of infertility in women. Doctors have reported a sharp increase in infertility during the years of IUD use, although sexually transmitted diseases, not IUDs, are the leading cause of pelvic disease.
The risk of the disease is greatest among users of the Dalkon Shield, an IUD whose manufacture was halted in 1974 because of many complaints by users and doctors of ill effects. What has not been clear in the past, however, is the risk in using other IUDs, the article says.
The report was written by a group of eight statisticians and doctors from Boston University, Harvard University and the University of Pennsylvania, headed by Dr. David Kaufman of Boston University's Drug Epidemiology Unit.
They studied 460 women under 45, of whom 155 had suffered pelvic disease and 305 had not. They found that nine of the 11 women who had used the Dalkon Shield had developed severe pelvic disease.
But 12 out of 40 women, or 30 percent of those who had used one of the popular copper IUDs, had also contracted severe forms of the disease. So had nine out of 32 women, or 28 percent, of those who had used another popular IUD called the Lippes Loop.
These figures may be overestimates because of the nature of the statistical sample, said Dr. Peter Layde of the federal Centers for Disease Control. Still, he added in an AMA Journal editorial, the study confirms the increased risk of pelvic disease for all IUD users. He estimated in an interview that IUD users have "roughly double" the risk of developing the disease compared with women who use no contraception.
The risk would be somewhat less for those who do not use the Dalkon Shield, he said, but somewhat greater compared with users of oral contraceptives or so-called barrier contraceptives such as condoms and diaphragms. Both birth control pills and barrier contraceptives seem to provide a degree of protection against pelvic disease.
Ten to 20 percent of all cases of pelvic disease may be caused by IUDs, compared with the 50 to 75 percent related to sexually transmitted diseases, he estimated.
Somewhere between 10,000 and 100,000 women still use the Dalkon Shield despite repeated warnings, he added. He said they should replace it with another IUD or use another birth control method.
The American College of Obstetricians and Gynecologists has called IUDs "acceptable" for many women. But Dr. Prabodh Gupta, a Johns Hopkins University pathologist who has studied IUD use, said last year that "there is no safe IUD."
At most, IUDs should be used only by women who have already delivered the children they want and may be planning eventual sterilization, Gupta said yesterday. Most doctors, said Layde of the CDC, now avoid prescribing the IUD for the women facing the highest risk of pelvic disease--"younger women and women who are sexually active with more than one partner."
Any woman using an IUD should have a pelvic examination yearly, Gupta said, and be alert for signs of pelvic disease: pain or tenderness in the pelvis or lower abdomen, vaginal discharge or fever, "although fever usually means quite a serious, late stage of infection."