The coil is a device intra-uterine Abortif (DIU) invented in 1928 by Ernst Gräfenberg. It is about the reversible method of birth control most largely used.

The device is installed in the uterus (or withdrawn) by a doctor or a qualified medical personnel and, remains in place as long as contraception is desired.

There exist two types of coil:

• the traditional coils (called coils with copper) contain copper which has a spermicide effect and causes a light ignition of the mucous membrane which makes it unsuitable to nidation.
• hormonal coils diffusing of the Progestatif S.

The women can choose the coil because once this device set up, they can forget it during years, contrary to other forms of Contraception (in fact, the coil itself concerns the Contragestion rather). The women who wish to avoid the use of artificial hormones and their undesirable effects with short or long run can choose the coils with copper. Nevertheless, those can make the Menstruation S more abundant or more painful among certain women, in particular during the first months after insertion. But the modern types as the GyneFix were conceived not to disturb the menstruations.

The coils do not protect from the STI and if an infection is declared by using a coil, it is likely to be propagated with the Utérus.

The coils remained unpopular in the United States since the lawsuit Dalkon Shield: the coils were prohibited after having caused several indirect deaths (by increasing the risk to contract uterine infections which can be fatal) and that was dramatized by the press. The modern coils on the other hand are much surer and the rare complications.

The intra-uterine devices can be used like emergency Contraception to prevent the pregnancy up to 7 days after sexual relations without protection. It is a very effective alternative to the Pilule of the following day.

Effectiveness

According to the type, the coils remain usually effective during 2,5 or 10 years. The hormonal coils are as effective as the contraceptive pills while the effectiveness of the coils to copper ranges between 98 and 99% according to the mark.

• See also the detailed article Effectiveness of the methods of birth control.