宫内避孕器是控制生育简便而有效的方法,各国应用者逐年增加,估计目前全世界带环者有千万人以上。根据Tietze和Lewit(1970)随访6年的报道,有将近50％的妇女经6年的应用仍在继续,其受孕率、脱环率、和因症状中止者随应用年限的增加,逐年下降,较其它避孕法为优。环的避孕 Intrauterine device is a simple and effective method of birth control, increasing the number of users from all over the world, it is estimated there are more than 10 million people around the world ring. According to a 6-year follow-up by Tietze and Lewit (1970), nearly 50% of women continue their use for 6 years, with conception rates, withdrawal rates, and those with symptoms discontinued as years of use decline, Better than other contraceptive methods. Ring contraception