title: Absence of circulating chorionic gonadotropin in wearers of intrauterine contraceptive devices.
abstract: Daily measurements of human chorionic gonadotropin (HCG) beta subunit, luteinizing hormone (LH), and progesterone were carried out in 24 subjects wearing intrauterine contraceptive devices. Detectable HCG was not found in any subject, but in four subjects delayed LH pulses resulted in apparent low levels of HCG because of cross-reactivity in the HCG beta subunit radioimmunoassay.
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood* / Q000378:metabolism; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007435:Intrauterine Devices, Copper; D008183:Luteal Phase; D007986:Luteinizing Hormone / Q000097:blood; D011247:Pregnancy; D011863:Radioimmunoassay
chemical_list: D006063:Chorionic Gonadotropin; D007986:Luteinizing Hormone