宫内节育器的最初发现与治疗痛经有关,痛经的主要原因是经血淤滞于宫腔内,不能经颈管流出,为此,人们采用在宫内放置撑开式子宫托将颈管撑开使淤积的经血流出,明显改善了痛经症状。不久还发现,宫内持续放置撑开式子宫托可以防止怀孕,其避孕作用一方面是由于子宫托在局部会引起异物反应,更主要的是在放置子宫托的过程中破坏了宫颈的防护因子,造成生殖系统感染所致。 The first discovery of intrauterine device is related to the treatment of dysmenorrhea. The main cause of dysmenorrhea is menstrual blood stasis in the uterine cavity, which can not flow out through the cervical canal. Therefore, people use distraction pessary to place the cervical canal open in the uterus Stained menstrual flow out, significantly improved the symptoms of dysmenorrhea. Soon also found that intrauterine sustained open distraction pessary can prevent pregnancy, the contraceptive effect on the one hand due to the pessary in the local cause foreign body reaction, more importantly, in the process of placing the pessary destroyed the protective factor of the cervix , Resulting in reproductive system infection.