title: Diurnal variation of semen quality in human males.
abstract: The possibility of a diurnal variation in semen quality was tested in 54 human males attending our infertility clinic. Of the enrolled subjects, 24 were normozoospermic and 30 were suffering from oligo- and/or asthenozoospermia. Seminal fluid was collected by masturbation twice by each subject, once in the morning (7:00-7:30 a.m.) and once in the afternoon (5:00-5:30 p.m.). Abstinence from sexual intercourse for 3-4 days before each of the two collections was requested. Semen parameters were evaluated independently by two biologists before and after pellet swim-up. Beside similar macroscopic parameters, specimens collected in the afternoon showed a higher number (P < 0.01) and concentration (P < 0.01) of spermatozoa. Also, immediately (P < 0.05), and at 1 h (P < 0.02) and 2 h (P < 0.01) after pellet swim-up, the number of spermatozoa with progressive linear motility was higher in the afternoon than in the morning. These data are the first documenting a diurnal rhythm in sperm quality which may contribute to the reported variability in semen parameters, and may prove useful for spontaneous and assisted conceptions.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Modena, Italy. cagnacci@unimo.it
authors.forename: A
authors.initials: A
authors.lastname: Cagnacci
authors.forename: N
authors.initials: N
authors.lastname: Maxia
authors.forename: A
authors.initials: A
authors.lastname: Volpe
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D007248:Infertility, Male / Q000503:physiopathology; D008297:Male; D009845:Oligospermia / Q000503:physiopathology; D012016:Reference Values; D012661:Semen / Q000502:physiology*; D013076:Sperm Count; D013081:Sperm Motility / Q000502:physiology