The result was the plastic double “S” loop—a trapezoidal-shaped IUD that closely fit the contours of the uterine cavity, thereby reducing the incidence of expulsion. First distributed in 1962, the ...

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 ...