Experience with polyethylene ring: 1955-1965. 1.
D000022:Abortion, Spontaneous / Q000209:etiology; D000293:Adolescent; D000328:Adult; D003273:Contraceptive Devices / Q000009:adverse effects; D005260:Female; D005831:Genital Diseases, Female / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy