Medical School to Test New IUD Contraceptive.

2001 JAN 18 - (NewsRx.com) -- Eastern Virginia Medical School (EVMS) scientists are studying a new contraceptive that combines an intrauterine devices (RID) with one of the chemicals found in birth control pills.

Researchers don't expect the product, Mirena, to become wildly popular. Intrauterine devices are some of the least-used methods of family planning in the country, chosen by less than 1% of women who use birth control. But Dr. Susan Ballagh, an assistant professor of obstetrics and gynecology who's leading the study, said the new system, which lasts up to five years, provides convenience and protection not found elsewhere.

Mirena was approved by the U.S. Food and Drug Administration (FDA) in December 2000. Norfolk doctors plan to test it with 20 local women to see whether they like it, Ballagh said.

Mirena has been sold in Europe for 10 years. It has been used by two million women worldwide, according to its manufacturer, New Jersey-based Berlex Laboratories Inc., which is sponsoring the EVMS study.

The device prevents pregnancy by releasing tiny amounts of the hormone levonorgestrel into the uterine lining, Ballagh said. That hormone, which belongs to a class of chemicals called progestins, is one of the two types of hormones typically found in the pill. Mirena has several advantages over oral contraceptives, Ballagh said, as well as different risks.

Whereas the hormones in birth control pills circulate through the bloodstream, the progestin in Mirena is delivered directly to the uterus, Ballagh said. That means that the new device needs much less hormone, one-eighth the amount found in the pill. Although Mirena is only about the size of a quarter, it contains enough chemicals to be effective for five years.

"It's more potent, so you can pack more drug in this tiny little system," said Ballagh. "Once it's in place, you don't have to think about birth control again for five years."