title: Incidence of the luteinized unruptured follicle phenomenon in cycling women.
abstract: A prospective study is presented in order to determine the frequency of the luteinized unruptured follicle (LUF) in a population of 66 regularly cycling women. They were monitored by daily ultrasound for a total of 183 cycles, and the LUF was detected in 9 cycles, giving an incidence of 4.9%. The results of daily changes of luteinizing hormone, estradiol, and progesterone provide support for the thesis that the LUF behaves steroidogenically as a corpus luteum and that the luteal phase duration is normal. Continued monitoring in 35 cycles revealed a recurrence in only one case during a fourth subsequent cycle. Thus, the findings indicate that the LUF is a sporadic and infrequent phenomenon. It is therefore an uncommon cause of infertile cycles in potentially fertile women and represents a biologic variable rather than a syndrome. Based on ultrasonic and endocrine observations, a mechanism is proposed for the resolution of the LUF.
mesh_terms: D000328:Adult; D003338:Corpus Luteum / Q000502:physiology; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000209:etiology; D007986:Luteinizing Hormone / Q000097:blood; D008598:Menstruation; D006080:Ovarian Follicle / Q000033:anatomy & histology / Q000502:physiology*; D010060:Ovulation; D011446:Prospective Studies; D013997:Time Factors; D014463:Ultrasonography
chemical_list: D007986:Luteinizing Hormone