Intrauterine Devices: Separating Fact From Fallacy

, Magee-Womens Hospital, University of Pittsburgh School of Medicine

In This Article

Currently Available IUDs

Currently, 2 IUDs are available in the US: the copper T 380A(ParaGard, produced by Ortho Pharmaceutical Corporation) and the progesterone T (Progestasert, from ALZA Pharmaceuticals). Both provide effective and safe contraception, and both contain barium sulfate to make them radio-opaque.

The ParaGard, a T-shaped device (Fig. 1) with a polyethylene frame with 380mm^2 of exposed surface area of copper, was introduced in the US in 1988. The copper wound around the stem is similar in design to the T-shaped copper-containing devices that preceded the ParaGard. However, the ParaGard also has 2 copper sleeves on the horizontal arms, and this combination of solid and tubular copper increases the effectiveness and life span of the ParaGard compared with older copper-containing IUDs. ParaGard is categorized by the FDA as a drug rather than a device since its effectiveness is dependent on the presence of the copper. The frame is polyethylene, the same substance as used in nonmedicated IUDs (eg, the Lippes' loop). The size of the ParaGard does not affect its contraceptive action as it does with nonmedicated IUDs. The Progestasert (Fig. 2) was introduced in the US in 1976. This IUD is a T-shaped device composed of ethylene/vinyl acetate copolymer containing titanium dioxide. The 36-mm tubular vertical stem contains 38mg of progesterone dispersed with barium sulfate in a silicone fluid. Progesterone is released at a rate of 65ug daily with mostly local effects.

Figure 1. The ParaGard IUD is a polyethylene T-shaped frame holding 380mm 2 of exposed surface area of copper in 2 copper sleeves on arms and tubular copper wrapper around stem. Photo courtesy of Ortho Pharmaceutical Corporation.
Figure 2. The 36-mm stem of T-shaped Progestasert IUD contains 38mg of progesterone that is released at rate of 65ug daily. It must be replaced annually as progesterone is depleted. Photo courtesy of ALZA Pharmaceuticals.


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