Fertility prognosis for infertile men: results of follow-up study of semen analysis in infertile men from two different populations evaluated by the Cox regression model.
Using the Cox proportional hazard regression model on one material (group I = 765, 1950 to 1951) we have identified four variables of semen analysis with significant prognostic information about fertility. The four variables were combined into a model for establishing the probability of the individual male to achieve pregnancy as a function of time. This model is tested first on another material (group II = 321, 1977 to 1985). A Goodness-of-fit test indicates excellent agreement between the expectations from the model and the observed number of pregnancies in group II. Second, the two groups are pooled (= 1,086). Then only three variables give significant prognostic information about the time until pregnancy: (1) the man's age at semen analysis (years); (2) the percentage of morphologically normal spermatozoa (ln %); and (3) the degree of motility (good/poor). These three important variables enter into a new and better prognostic model.
Bostofte
E
E
Sperm Analysis Laboratory, Health Service Physicians Organization, Pilestraede, Denmark.
Bagger
P
P
Michael
A
A
Stakemann
G
G
D005260:Female; D005298:Fertility; D005500:Follow-Up Studies; D006801:Humans; D007248:Infertility, Male / Q000503:physiopathology*; D008297:Male; D008954:Models, Biological; D010331:Paternal Age; D011247:Pregnancy; D011379:Prognosis; D012044:Regression Analysis; D012661:Semen / Q000502:physiology*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000473:pathology