The semen of fertile men. II. Semen characteristics of 100 fertile men

Abstract

From a population of men applying for voluntary sterilization, 100 consecutive cases were selected according to the following criteria: (1) each man had fathered at least two children; (2) at the time of the request for a vasectomy the man's wife was pregnant; and (3) a complete prevasectomy semen analysis, including sperm morphology, was available. The usual parameters of human semen evaluation are reported: the mean volume of the ejaculates was 3.3 ml +/- 0.84 SD (range, 0.5 to 11 ml); the mean sperm density was 81 million/ml +/- 57 SD (range, 4 to 318); while the geometric mean, which according to the sample distribution is more representative, was 68. The mean percentage of motile sperm was 63% +/- 16 SD (range, 10 to 95%); the grade of forward progression was 3 +/- 0.55 SD (range, 2 to 4); and for sperm morphology the mean number of sperm with oval heads was 75% +/- 6 SD (range, 21 to 90%). Statistical comparison of these findings with those of our previous study of the semen of 1300 fertile men revealed complete agreement; minor statistical differences, on single parameters, with three similar studies are indicated. A positive relationship between the different variables, sperm density and sperm motility (in percentage of motile sperm and degree of forward motion), as well as between the two variables of sperm motility and sperm morphology to the other variables was confirmed.

PIP: In a previous report the characteristics of 1300 consecutive prevasectomy semen specimens of men who had fathered 2 or more children were analyzed. From the same population a group of subjects was selected whose wives were pregnant at the time of the semen analysis. From the files of the Vasectomy Service at the Margaret Sanger Research Bureau, Inc. in New York City, 100 consecutive men whose prevasectomy semen analysis reports fulfilled the following criteria were selected: the man had fathered 2 or more children and his wife was again pregnant at the time of the prevasectomy semen analysis; and the prevasectomy semen analysis was complete, including the evaluation of morphology. Each prevasectomy semen specimen was collected by masturbation. The analyses were made within 90 minutes-3 hours postejaculation. Study results are reported in terms of volume, sperm density, motility, sperm morphology, and semen quality and age. The volume of the ejaculate in the population studied ranged from 0.6-11 ml. The mean volume for these 100 fertile men was 3.31 ml +or- 1.84 SD. The sperm density, or count per milliliter, ranged from 4-318 million. The mean value for these 100 men was 81 million +or- 57 SD. The geometric mean, which is considered to be more accurate, was 68 million. The percentage of active sperm cells ranged from 10-95. The mean number of active cells was 63% +or- 16 SD, with the greatest proportion (70%) in the group having 40-80% motility. The quality of sperm motility was graded according to MacLeod's system of estimating grade of activity and forward motion from 0, or total immobility, to 4. In the 100 semen specimens the quality of sperm motility ranged from grade 2-4. In these 100 specimens the percentage of sperm with oval heads ranged from 21-29; the mean was 73% +or- 6 SD. There was no sound basis for stating whether any difference between different groups was due to the difference in age or whether it merely reflected individual situations, as is most likely the case. The findings are compared to the investigations of MacLeod, MacLeod and Gold, and Falk and Kaufman. A positive relationship between the different variables, sperm density, and sperm mobility, as well as between the 2 variables of sperm motility and sperm morphology to the other variables was confirmed.