Semen Quality in One Thousand Men of I(nown Fertility and in Eight Hundred Cases of Infertile Marriage. John Macleod, Ph.D.

Transcription

1 Semen Quality in One Thousand Men of I(nown Fertility and in Eight Hundred Cases of Infertile Marriage John Macleod, Ph.D.. THE DATA presented in this paper represent: (1) a study of semen quality in 1000 married men whose wives were pregnant at the time the semen examination was made. Forty-one per cent of the wives were undergoing their first pregnancy, 35 per cent their second, 13 per cent their third, and only 10 per cent had had four or more. The 1000 single semen specimens (in a relatively small group of cases where the original specimens were poor, repeat examinations were made) were obtained over a period of a full year. They were studied concurrently with, (2) 800 semen specimens from individuals who had presented themselves for examination because of infertile marriage. The complete details of the conditions of the study appear in the July, 1950, issue of this JOURNAL, but several of these points are emphasized here: 1. All the motility and morphology examinations were made by one observer. 2. These examinations were made in such fashion that the observer was not aware of whether the specimen under examination was from an individual in the fertile or "infertile" group. 3. The semen specimens were obtained either by masturbation or withdrawal, although the instructions specified "masturbation." From the Departments of Anatomy and Obstetrics and Gynecology, Cornell University Medical College, New York. Presented before the Sixth Annual Conference of the American S?ciety for the Study of Sterility, San Francisco, June 25, I am deeply indebted to Corneli~s Vanderbilt Whitney for the financial aid required in this study. Ruth Z. Gold is responsible for the statistical analysis. I am most grateful to her for her painstaking and arduous work. 115

2 116 MAC leod [Fertility & Sterility The primary aims of this study are: 1. To study the characteristics of semen from fertile men and to compare them with those of semen from men whose wives had difficulty in conceiving. 2. To determine with as much precision as statistical analysis will allow, the lowest semen standards compatible with relative ease of conception. 3. To determine the best conditions which will allow the male to deliver semen of the quality defined in (2) above. RESULTS It would be impossible in such a short time to give a complete analysis of the results obtained to date. In order that this conference receive a com- TABLE 1. Averages by Hundreds of 1000 Fertile Men In Order Volume in cc. G ount / cc. in Millions Total Gaunt in Millions of Arithmetic Standard Arithmetic Standard Arithmetic Standard Observation mean deviation mean deviation mean deviation 1st hundred nd rd th th th th th th th Total Differences among means Not Significant Significant Significant prehensive survey of this study, I propose to present a summary of our findings in regard to all aspects of semen quality.., 1. Volume The mean (average) ejaculate volume for 1000 fertile men is 3.4 cc. as compared to an average volume for the 800 infertile men of 3.6 cc. (Tables 1 and 2, Fig. 1). This is a significant difference and we feel that the difference between the two means is contributed by the poorest semen specimens in the infertile group. Both figures, however, are quite close to figures already quoted in the literature with one exception.

3 '" Vol. 2, No.2, 1951] SEMEN QUALITY 117 Azoospermias have not been included in the "infertile" group-if they are included in any group, the average volume will be lowered considerably since we have found the average volume for 300 azoospermias to be 2.72 cc. TABLE 2. Averages by Hundreds of 8UO Men in Infertile Marriage In Order Volume in cc. Count/cc. in Millions Total Count in Millions of Arithmetic Standard Arithmetic Standard Arithmetic Standard Observation mean deviation mean deviation mean deviation 1st hundred nd rd th th th th th 3, Total Differences among means Not significant Not significant Not significant We have found no significant change in semen volume (Table 3) in the ages between 20 and 45 years in the fertile men, the median semen volume in fertile men under 25 being 3.11 cc. whereas in the age group over 40, the Cumulalive Frequency ( %) Iu.t.ik (1000 Ca.e.) Cumulalive 25% --- Frequency 23% 19% (BOO Ca.es) Cumulalive ~quency ">\' ,6 p=.2 9% , q, (2.4)(14) Volum. in Cubic C.nlimelers FIGURE 1. Relative frequency distributions of ejaculate volume in 1000 men in fertile marriage and 800 men in "infertile" marriage. Q1 and Q2 indicate first and second quartiles.

4 118 MAC LEOD [Fertility & Sterility median volume is 3.19 cc. We have not completed our analysis of the "infertile" group by age so that we cannot compare both groups at this time. It is pertinent to inquire what relationship there is between semen volume and the date of the previous emission, and, of course, what should be the minimal period of continence to give a representative volume. In the fertile group, the median semen volume ranges from 3.0 cc. in the "3 days or under" group to 3.2 cc. in the "14+ days" group, with a peak level of 3.4 cc. in the 5-6 day group. These differences, however, are not significant. However, in the "infertile group" the median volume shows a gradual increase from 3.0 cc. in the "3 days or under" classification to 3.9 cc. in the "14 days +" group. We are not prepared to state now that this represents a definite difference between the "fertile" and "infertile" men because we do not have the same reliance on the veracity of the "fertile" group. In every case, the wife brought the specimen and gave the information on the last emission whereas in virtually every case in the "infertile" group the husband brought the specimen and gave the information. 2. Sperm Counts The grand means for counts/cc. and total counts for the fertile men are 107 and 350 million respectively (Table 1). Taken in groups of 100 as the specimens were received in the laboratory the averages per 100 range all the way from 130 million/ cc. with a total of 432 million to 88 million/ cc. and a total of 290 million. There is thus a considerable swing to and from in these means which is statistically significant, but we have not been able to pin this significance to any known factor. There is no seasonal variation. In the "infertile group" (Table 2) the grand means for 800 men are 87 million/ cc. with a total count of 293 million, considerably lower, as one could expect, than the fertile men. Taking the infertile group by hundreds, the means are considerably more homogeneous than the fertile men, ranging from 66 to 95 million/ cc. and from 221 to 356 million. There is no significant difference between these means. The means, however, hide rather than show the essential differences between the two groups. For example, the fifth and seventh averages of the fertile men virtually are the same as most of the averages of the "infertile" men. If these two means were selected deliberately it would be easy to say that there is no difference between the two groups. It is only when one..

5 Vol. 2, No.2, SEMEN QUALITY 119 examines the relative frequency distributions (Fig. 2) of the sperm counts in the two groups that the pronounced differences become apparent. Taking the fertile group, 25 per cent fall below the 54 million/ cc. count level, with 5 per cent (50 individuals) having counts between 1 and 20 million/ cc. We shall show below that it makes little difference whether one considers the count! cc. or total count. These are striking facts in themselves inasmuch as most of the present semen standards would place such specimens in the "poor category" although it should be remembered that Hotch- Cumulative Frequency (%) Fertile ( rllio(;;;es) Infertile (.ooc.;;.) X2= n=1i P<.oor 10 Count Per (( in Millions FIGURE 2. Relative frequency distributions of sperm counts per cc. in 1000 cases of fertile marriage and 800 "infertile" marriages. Q1 and Q2 indicate first and second quartiles. kiss found 25 per cent of his fertile men with counts less than 60 million/ cc. (29 per cent of our fertile men fall in this range). When these figures are compared with those of the "infertile marriage" group, the differences are definite and striking. Where the first quartile of the fertile group are below 54 million/ cc. and 5 per cent fall between 1 and 20 million, the first quartile of the "infertile" group is under 30 million / cc. and 17 per cent (136 individuals) fall between 1 and 20 million. In fact, the modal group in the "infertile" men lies between 1 and 20 million whereas the similar group in the fertile men lies between million. The total sperm counts (Fig. 3) show the same sort of distribution picture for the fertile group lying under 152 million in contrast to that for the "infertile" group which is under 91 million. The modal group for the fertile

6 120 MAC LEOD [Fertility & Sterility Cumulative Frequency ("!o) Fertile (1000 Cases) 27% Infertile (BOO Casu) liiii"':ljf:i"!!il~ 40 I!iHli'it ie n :9 P<.OOI Total Sperm Count in Millions FIGURE 3. Relative frequency distributions of total sperm counts in 1000 cases of fertile marriage and 800 "infertile" marriages. Q1 and Q2 indicate first and second quartiles. men lies between million though this is rather deceiving inasmuch as a second modal group lies between million and there is little to choose between the two groups. To summarize the data on counts it may be said that tabulation of counts on fertile men shows that more men fall in the 60 to 79 million group than * TABLE 3. Average Volume, Count/cc. and Total Count by Age Number of Cases Average Volume Average Count/ee. Average Total Count Age Fertile "Infertile" Fertile "Infertile" Fertile "Infertile" Fertile "Infertile" Under III Total in any other 20-million group. By contrast more "infertile" men fall in the 1 to 19 million group than any other. In examining the count/ cc. and total counts by age groups in the fertile men (Table 3), there is a definite tendency for the count/ cc. to increase with increasing age up to approximately 45 years (the median count in the

7 Vol. 2, No. 2,1951] SEMEN QUALITY 121 "under 25" age group being 84 million and 100 million in the "40+" age group). However, the total counts reach their peak between 25 and 35 years, being low in the "under 25" and in the "35 to 40+" age groups. This discrepancy may be accounted for by the greater frequency of intercourse in the "under 25" age group and by the slight decrease in volume in the "40+" age group. Broadly speaking, however, the ejaculate volume and sperm counts remain remarkably constant throughout the reproductive years in fertile and infertile men. In regard to age, one Significant factor is emerging: in the infertile group, a longer period between emissions is reported by the older age groups, a factor which does not seem to hold true in the fertile men. There are several reasons why this might be so, the main one being that the marital lives of the fertile men are probably normally adjusted whereas those in the "infertile group," particularly in the higher age brackets, have undergone a considerable amount of psychologic strain because of their infertility. One other factor is, of course, the reliability of information given by both groups. Lastly, the compulsion to provide semen specimens is different in each group. This may lead to the "infertile" men consciously providing specimens after a longer period of continence in order that the specimen they provide may be "better" as a result of the continence. A final consideration in regard to factors influencing the sperm counts is the relation of the counts to the time of the previous emission. In the fertile group, there is a definite rise (but only a mildly significant one) in the median count/ cc. as the time of the previous emission ascends from "3 days or under" to "14 days +." There is an indication that a period of continence between 5-6 days should be the minimal time necessary for best semen quality but it would be just as true to say that, for the infertile group at least, it would be better to wait at least two weeks. Subjecting the "infertile group" to the same analysis, the peak median count/cc. is reached at 7-13 days since the last emission, a rather lower median count being apparent in the 3 days or under group (52 million/cc. and a total count of 156 million in the "3 days or under" group as compared to 85 million/ cc. and a total count of 306 million in the "7-13 day" group). Though these differences in the sperm counts in relation to the time of the last emission are only mildly Significant the evidence indicates that in the cases of "infertility" a period of continence of at least one week would provide maximal quality in the semen specimen insofar as sperm counts are concerned.

8 122 MAC LEOD [Fertility & Sterility SPERM COUNTS IN A GROUP OF "INFERTILE" MEN WHO DID OR DID NOT EVENTUAllY CAUSE CONCEPTION It goes without saying that all the males in any "infertile marriage" group are not "infertile" insofar as semen quality is concerned. It is equally true to say that while in this study we are concerned only with the male, we must eventually complete the picture by correlating the histories of both partners in the marriage. In a large percentage of cases of "infertile" marriage, conception eventually results. In such cases, it is pertinent to study semen quality in the male who eventually produces conception, irrespective.. Fonow up CaslS Cumulative Frequency (%) io 70 Conceptions (DO Ctlses) No (onceptions 1316 Case.) X=I2.3S n=s P=.03 Relative frequency distributions of sperm counts per cc. in 666 cases of "infertile" marriage of which 350 eventually produced conception and 316 failed. FIGURE 4. of his wife's history. Before passing on to a discussion of motile activity, we will present data on sperm counts in 666 cases of "infertile marriage" followed for one to four years to determine if conception eventually resulted. The 666 replies we received from various clinics and doctors report that more than 50 per cent of the wives eventually conceived. An analysis of the data on the semen specimens of the husbands shows that if one takes only average counts, the group eventually producing conception ("conception group") had about the same average counts/cc. as the "no conception group" (100 million/cc. for the first and 92 million/cc. for the second). It is

9 Vol. 2, No.2, 1951] SEMEN QUALITY 123 in the relative frequency distributions that the differences really appear (Fig. 4). The modal group in the "conception" class lies between 40 and 60 million/ cc. as compared to the modal group of million/ cc. for the fertile men. But the modal class for the "no conception" group is between 1 and 20 million, exactly the same as that for the "infertile" group. These differences between the four groups are shown quite strikingly if one takes Follow.up Cases 29% Cumulati.e frequency (%J I 24% Conceptions (ISO Ca ) No Conceptions (316 Ca ) ~O X n: 7 P<.001 Total Sperm Count in Millions FIGURE 5. Relative frequency distributions of total sperm counts in 666 cases of "infertile" marriage of which 350 eventually produced conception and 316 failed. the first quartile of the four groups and plots them on the same graph (Fig. 6). In this fashion it is shown that in both counts and total counts, the men who produced conception eventually in the "follow-up" group had poorer semen quality than the fertile men but much better than the "infertile men" and the "no conception" group, the latter two being virtually the same. This analysis is incomplete because the wife's history has not been taken into account but we believe that we are presenting the best possible picture for the "infertile" group, the "goodness" of the sperm counts being exaggerated. It should be pointed out that in the "no conception" group there remains a relatively large number of men whose semen quality is good by all our standards and whose wives could never conceive because of some

10 124 MAC LEOD [Fertility & Sterility gynecologic disorder such as closed tubes. If these men were removed from the "no conception" group, the remaining relative frequency distributions would be quite different. Motility In determining motile activity we have continued to follow the criteria used by us for years and which have, in our hands, proved the most useful. SPERM COUNT I ~ Fertile 710 Cases Infertile 680 \J Conceptions 309 ii":i:i;:: No Conceptions SO Count per Cubic Centimeter Total Count % Active Cells Motility Index FIGURE 6. Comparison of first quartiles of sperm counts per cc., total sperm counts, and "motility index" of 1000 fertile men, 800 "infertile" men, 350 "infertile" cases in which conception eventually resulted, and 316 "infertile" cases who failed to produce conception. The percentage of active cells is estimated by the scanning of several high power elds and the quality of progressive movement is designated arbitrarily as 4, 3, 2, 1, 4 being the best quality of motility and any quality below 3 being considered subnormal. The "percentage of active cells" means the number progressing at the quality designated. For example, "3+ 50 per cent" means that 50 per cent of the cells are travelling at the quality of 3+ even though another 20 per cent of the cells may show relatively feeble

11 Vol. 2, No.2, 1951] SEMEN QUALITY 125 activity. In this study we have gone further and weighted the motility in terms of the combined percentage active and quality by multiplying the two figures. The result is the "motility index." For example "3+ 50 per TABLE 4. Averages by Hundreds of 1000 Fertile Men Morphology (% normal cells) Motility (at 5 hrs. or less after e;aculation) In Order % active cells Motility index of No. of Arith. Stand. No. of Arith. Stand. Arith. Stand. Observation cases mean dev. cases mean dev. mean dev. 1st hundred nd rd II th th th th th th loth Total Differences among means Significant Not significant Significant Morphologies included for specimens with count/ cc. of at least 30 million. TABLE 5. Averages by Hundreds of 800 Men in Infertile Marriage Morphology (% normal cells) Motility (at 5 hrs. or less after e;aculation) In Order % active cells Motility index of No. of Arith. Stand. No. of Arith. Stand. Arith. Stand. Observation cases mean dev. cases mean dev. mean dev. 1st hundred nd rd th th th II th th Total Differences among means Significant Significant Significant cent would be classified as 3.5 X 50, giving a " motility index" of 175. We have found this index most useful in statistical analysis, as we shall show presently.

12 126 MAC LEOD [Fertility & Sterility We have found the averages of percentage of active cells for the fertile and "infertile" marriage groups at five hours or less to be 58 and 51 respectively (Tables 4 and 5). These differences would not seem to be important if averages alone were considered. It is in the relative frequency distributions (Fig. 7) that the real differences appear. Both have the same modal groups (60-70 per cent) but whereas 20 per cent of the "infertile" men had less than 40 per cent active cells, only 9 per cent of the fertile men showed this subnormality. Similarly, 12 per cent of the "infertile" men showed less than 30 per cent active sperm as compared to only 5 per cent in the fertile men. Cumulativ. Frequency 1"10/ 1( Fertile (iioc;;',) Infertile (u;c;;;,) X n.6 P< FIGURE 7. "10 Active Cells (At Five Ho.".r leu) Relative frequency distributions of "per cent active" spermatozoa in semen of 1000 fertile men and of 800 men in "infertile" marriage. Similarly, in examining the figures for "quality of motility" (Figs. 8 and 9), 20 per cent of the fertile men showed subnormal motility by our standards as compared to 32 per cent of the "infertile" men. It is not easy at this stage of the analysis to assign to motility alone a circumscribed responsibility in infertility. We are all aware of its importance but as we all have been equally aware, it cannot be considered apart from the sperm count. What is the relationship between motility and the sperm count? We cannot find this clearly by simply taking the data from the fertile and "infertile" groups. It is only by determining what the "infertile" men eventually accomplish that we can bring the various factors into their true perspectives. If we return to the "follow-up" of the "infertile group" and 'f

13 Vol. 2, No.2, 1951] Cumulative Frequency (%) SEMEN QUALITY Fertile (110 Cases) % o Infertile (610 Cases) o 15% l FIGURE 8. QUALITY OF MOTION (At live Hours or Less) X 2 : n: 3 p =.001 Relative frequency distributions of quality of motility in spermatozoa in semen of 1000 fertile men and of 800 men in "infertile" marriage. Cumulative Frequency (%) Infertile (680 Cases) X 2 :42.30 n=6 P<.OOI FIGURE 9. Motility Index (At five Hours or Less) Relative frequency distributions of "motility index" in spermatozoa in semen of 1000 fertile men and of 800 men in "infertile" marriage.

14 128 MAC LEOD [Fertility & Sterility examine the motility data in those who eventually produced conception and those who did not, we find that the frequency distributions for both groups are essentially the same above the range "30 per cent active" cells (Fig. 10). It is only in the lower ranges that any real difference appears, it being 7 per cent (12-19) in favor of the "conception" group. But if we consider the "motility index" (Fig. 11) which includes quality of motility, the difference between the two groups is accentuated inasmuch as in considering a motility Follow up Cases Cumulative Frequency (%) 24% 24% Conceptions (109 Cases) No Conceptions (266 Cases) ~ (AI Fiv. H rs or Less) Q, 02 (314) (53) FIGURE 10. Relative frequency distributions of "per cent active" spermatozoa in semen of 350 men in "infertile" marriage in which conception resulted eventually, and 316 "infertile" marriage cases who failed to produce conception. index under 50, the ratio increases to 6-15 in favor of the "conception" group. This would indicate the "per cent active" cells is not enough to describe the difference between the two groups but that in addition one must have a "better" quality of motility. This cannot be a new idea to most readers but it is reassuring to have our surmises borne out by analysis. An equally important question is whether poor motile activity is associated with low sperm counts and conversely whether good motility is linked with high sperm counts? Secondly, if either or both of these questions is answered positively, does the same pattern hold true for the fertile men as for the "infertile group"? Let us take arbitrarily a total sperm count of less

15 Vol. 2, No.2, 1951) SEMEN QUALITY than 100 million as being definitely subnormal (this would compare roughly to a count/cc. of 30 million or under) and look first at the fertile men in this category. Twenty-three per cent of these men had 70 per cent or more active cells and 69 per cent had 50 per cent or more active. Comparing these figures with the "infertile" group, the percentages in the latter are 17 and 54 respectively. If one examines, however, the "per cent active" classifica- Cumulative Frequency ( %) Follow-up Cases Conceptions (309 Cases) No Conceptions (266 Cases) x = n = 4 P<.03 Motility Index FIGURE 11. Relative frequency distributions of "motility index" spermatozoa in semen of 350 men in "infertile" marriage in which conception resulted eventually, and 316 "infertile" marriage cases who failed to produce conception. _ tion under 30 per cent in both groups, only 13 per cent (or 19 individuals) of the fertile men are found there as compared to 32 per cent (69 individuals) in the "infertile" group. It is in this classification that the essential difference between the two groups lies and it is a rather striking one. This difference is accentuated when one turns again to the "follow-up" group and examines the "conception" and "no conception" semen quality. Of the men who failed eventually to produce conception and had total sperm counts of less than 100 million, 46 per cent had less than 30 per cent active cells. Whereas, only 16 per cent of the men who produced conception

16 . 130 MAC LEOD [Fertility & Sterility eventually and whose total sperm counts were less than 100 million had less than 30 per cent active cells. Table 6 gives a complete analysis and comparison of means for all aspects of semen quality in the fertile and "infertile" men studied to date..,. Infertile (IS, Cases) Fertile (103 Cases) Conceptions (51 Cases) No Conceptions (66 Cases) FIGURE 12. Relative frequency distributions of "per cent active" spermatozoa in semen with total sperm counts under 100 million of fertile men, "infertile" men, "infertile" men whose wives conceived eventually, and "infertile" men whose wives failed to conceive. RElATION BETWEEN MOTILITY AND AGE OF INDIVIDUAL We have found no significant difference in the percentage of active cells in the fertile men between ages 20 and 40. The median percentage in the "under 25 years" group is 60 per cent as compared to 58 per cent in the "40 + years" group. But there is a definite fall in the motility index in the..

17 Vol. 2, No.2, 1951] SEMEN QUALITY 131 "40 + years" group which suggests that with study of larger populations in this age group, one will find a falling-off in the quality of motility. In comparing the "per cent active" cells in terms of "previous emission" in the fertile group we can find no significant difference whether the "p.e." is 3 days or under or 14 + days. However, the motility index in similar circumstances in the same group does tend to be lower when the previous emission has been one week or more before. Carrying these comparisons over to the "infertile" men, quite a different pattern presents itself. The percentage of active cells falls off perceptibly TABLE 6. Comparison of Means ~.. Fertile "Infertile" Difference between means No. of Stand. No. of Stand. Diff. Stand. error cases Mean dev. cases Mean dev. d of diff S. Conclusion Volume in ccs D78 Diff. signif. Count/ cc. in millions Diff. signif. Total count in millions Diff. signif. Normal forms (%) in counts under 30 million/cc Diff. si gnif. Normal forms ( %) in counts over 30 million/ cc Diff. signif. % active cells Diff. signif. Motility index Diff. signif. with increasing interval between emissions, the highest median percentage active being found at "4 days or under," the lowest at "14 days plus." Similarly, the motility index falls off considerably with time. We would prefer to analyze these factors further on larger populations before coming to definite conclusions. We can only say now that the differences we have noted are statistically significant, particularly in the "infertile" group... MORPHOLOGY Like much of the discussion of semen quality given in this paper, our analysis of morphology is by no means complete but we have progressed sufficiently to make some general statements with statistical validity. It is.

18 132 MACLEOD [Fertility & Sterility perhaps superfluous for me to point out that "standards" in morphology are rather elastic inasmuch as there is not complete agreement among authorities in regard to definitions of "normal" and "abnormal." Secondly, our analysis of any semen specimen in relation to morphology is not, for obvious reasons, done on the wet specimen where cells are functioning in a "physiologic" state and where one could relate the morphologic structure of the cell to its motile activity. If we assume, as we must in the light of present evidence, that for a spermatozoon to fertilize the ovum, it must have motile activity of reasonably good quality then, ipso facto, any and all cells of a given semen specimen with no motile activity or only feeble motility, are automatically ruled out of consideration. Any evaluation of morphology, therefore, should consider only the cells which, theoretically, are capable of reaching the ovum. Our methods of morphologic examination to date, all of which require staining of dried and fixed cells, classify all cells and do not differentiate between cells which showed good motile activity in the fresh semen and those which were inert. It follows, then, that unless we can show a good correlation between morphology and motile activity and prove beyond dispute that spermatozoa of poor morphology also have no or poor motile activity, we are only guessing at the fertility of any given specimen in terms of morphology. But even with the limitations in our methods and with the mild disputes as to what constitutes morphologic abnormality in the spermatozoa, these examinations must be done. In this study we have followed the Hotchkiss classification of "abnormal" forms with only one change. We have extended the classification of "small" cells to include sperm of otherwise normal morphologic contours but which obviously are only approximately half the size of the normal cell population. Our average percentage of "normal oval" forms for both fertile and infertile groups we believe are lower by about lo per cent than any figures on morphology published by us previously. There is one other reason for our not presenting a complete statistical analysis of morphology at this time. In the past, we have examined 333 cells in every semen specimen. Since only one observer (and I was the unfortunate one) performed all the morphology examinations in the present study, it was found physically impossible, because of the volume of specimens, to count such a large number of cells in every specimen. We attempted to cut down the number to 100 but have found (by a thorough statistical analysis) that our accuracy in reproducing a differential count on any given specimen in a series of examinations on this small number of cells was not satisfactory.....

19 . Vol. 2, No.2, 1951] SEMEN QUALITY 133 But we are prepared at this time to make certain generalizations on morphology which we feel certain will survive more thorough analytic treatment. At this point, we must introduce a numerical method of weighting semen quality which has allowed us to make statistical analyses where no other method would have allowed us to make them. We already have demonstrated the motility index which gives us an over-all picture of motility which takes into consideration in one figure both "percentage of active cells" and their quality of motility. If now we wish to analyze all but one aspect of semen quality in terms of the excluded one, we must combine in one "index" all qualities but the one to be compared. For example, if, as we propose to do now, we wish to find out what role morphology plays in fertility in relation to sperm count and motility, we must combine count and motility in one index and determine if there is any correlation between this index and the proportion of abnormal forms in any given specimen. This index therefore would be the motility index X total number of cells in the semen specimep (equation: percentage of active cells X total number of cells in millions, X quality of motion = weighted number of active cells in specimen). If, by this method, we classify the percentage of specimens containing more than 40 per cent abnormal forms in terms of decreasing or increasing quality of the index, we can determine the precise relationship to the other qualities of the semen. We have so far worked out the four major groups of individuals in this study. The conclusions we have reached are only tentative but the trends are definite. If we take the fertility and "infertility" groups and take all specimens with the "total count-motility index" under 100 and classify them according to the percentage of normal forms, we find that in the categories under "60 per cent normal" forms, there is a much higher proportion of cases in the "infertile" group. Only 3 per cent of the fertile men with this "index," had morphologies under 40 per cent normal as compared to 13 per cent of the "infertile" men. In the under "50 per cent normal" category, we find only 8 per cent of the fertile men as compared to 18 per cent of the "infertile" men. But with increasing percentage of ~ormal forms, we find the two groups coming close together until at the "under 80 per cent" mark, the two groups virtually are the same. A somewhat different picture presents itself, if we examine the better semen specimens in both groups-those with "count-motility indices" of 300 or above. Here we find that there is no such marked difference between the two groups. The number of "poor morphology" specimens in similar classifications in both groups is much the same. In only one category, namely

20 134 MAC LEOD [Fertility & Sterility under "60 per cent normal" forms is there a significant difference in favor of the fertile group. As before, we cannot complete this picture without consideration of the "follow up" groups. If we take the same classifications as those above, and consider the semen of men who did or did not eventually produce conception in the "follow-up" group, a far higher proportion of men who did not produce conception had spernl morphologies of less than "60 per cent normal forms" in the presence of low sperm count and poor motility. Whereas, in the same "follow-up" group with good "count-motility indices," the proportions of "poor morphologies" were approximately the same, irrespective of whether conception did or did not result eventually. In summarizing these preliminary findings on morphology, several features are prominent: 1. If the semen specimens have good counts and motility, the odds are heavily in favor of a normal complement of morphologically normal cells. 2. Conversely, low counts and poor motile activity carry with them relatively high percentages of morphologically poor cells. 3. However, in the studies on fertile men, specimens with low counts had consistently better morphology than the infertile group with similar counts. We have shown already that in the semen of fertile men with low counts, the motile activity was consistently better than similar specimens in the infertile men and that this was a compensating feattue. Relatively better morphology is also a compensating feature and there is a distinct possibility that morphology and motility are closely related if not synonymous. SUMMARY OF OTHER FACTORS ARISING FROM ANALYSIS OF THE DATA 1. Recently, a suggestion was made and data presented in the literature pulporting to show that the number of conceptions produced by any fertile male was related to the quality of his semen. There are so many other factors governing the number of children conceived by fertile couples that it would seem rather naive to name semen quality as a dominating factor. But we have applied this reasoning to an analysis of the men in our fertile group in terms of the number of conceptions produced by them. We can state now with good authority that up to three normal pregnancies at least there is no relationship between semen quality and the number of conceptions. 2. A more likely relationship to be sought is whether, in the fertile group,

21 .. ".. t Vol. 2, No.2, 1951] SEMEN QUALITY 135 more time is necessary to produce conception with semen of relatively poor quality. Wives of husbands in this group were asked how long it took to produce conception. We have taken the time necessary to produce the last pregnancy (the semen being examined within three to four months after conception) as our criterion and analyzed semen quality in terms of time taken to produce conception. The times ranged from "accident" to two + years and included "under three months," three to six months, six and under twelve months, twelve and under twenty-four months. In no case did we find any significant relationship between semen quality and time taken to produce conception. The full significance of this finding can only be determined when we have collected and analyzed sufficient data on the female partners. 3. It would be assumed tacitly by most of us that the highest frequency of intercourse would be found in the younger age groups and that this would perhaps affect the semen quality found in those groups. Among the fertile men, at least, we found a significant relationship between age and frequency, frequency decreasing with age. We have not yet analyzed the "infertile group" in this manner but as the time since previous emission is greater in the higher age groups of the infertile men, the chances are that relative infrequency is also higher in this group. CONCLUSIONS 1. Ejaculate volume in 1000 fertile men averages 3.4 cc. and in 800 "infertile" men 3.6 cc. The difference is statistically significant. If azoospermias are induded in the "infertile" group the mean volume would be considerably low inasmuch as in a separate study of 300 azoospermias, the mean ejaculate volume is only 2.72 cc. 2. Ejaculate volume is related to time of previous emission. This is more true of the "infertile" group inasmuch as there is a more significant increase in volume in the latter with increasing periods of continence. The peak level in the fertile group is reached at 5-6 days though there is no statistically significant difference between this volume and that of 3.0 cc. in the "3 days or under" group. In the infertile men the peak level of 3.9 cc. is reached at "14 + days" with no indication as yet as to how high the volume might go. 3. There is no significant change in volume in the age groups between 20 and 45 years. 4. In the fertile group, 29 per cent of the men had sperm counts below

22 136 MAC LEOD [Fertility & Sterility 60 million/ cc. as compared to 44 per cent of the "infertile" men. Only 5 per cent of the fertile men had counts in the 1-20 million/cc. bracket, as compared to 17 per cent of the "infertile" men. 5. The same general relationship holds true in a follow-up of "infertile" men who eventually produced conception. The men who eventually produced conception had much better sperm counts than those who did not, the latter virtually being the same as the "infertile" group. 6. The most important feature in regard to motility is that when one compares the "low count" specimens in the fertile and "infertile" groups, one of the essential differences between the two groups lies in the much better quality of motility found in the fertile men. The term "percentage active" is not enough to describe this difference. 7. In the fertile men, motility does not fall off markedly as age increases though in the "40 +" age group there is a definite tendency towards deterioration in quality of motility. 8. In terms of date of previous emission, the fertile men showed a tendency towards a lower percentage of active cells and poorer quality of motility with increasing time between emissions. But in the "infertile" group, this deterioration is quite striking, the median "motility index" dropping from 200 in the "3 days and under group" to 107 in the "14 + days" group. 9. We have made only a preliminary analysis of morphology but the indications are: (1) that abnormalities in morphology increase with decreasing count; (2) that they are found much more frequently in the infertile men with low counts; and conversely, (3) relatively good morphology is a "compensating" feature in the fertile men with low counts. DISCUSSION The striking feature of this study, we believe, is that the really significant differences are in the count range between 1 and 20 million/ cc. where more than three times as many infertile men as fertile men are to be found. In no other classification is there such a serious difference in the two groups. We have shown, furthermore, that there are compensating features in the fertile group (good motility and morphology) which are not present in the "infertile" group. In other words, if we took "count" alone and used our present standards, it would be rather difficult to consider the 5 per cent of men in the 1-20 million "fertile" group as really being fertile men. But the fact remains that they are. The other outstanding fact is that we cannot consider

23 Vol. 2, No.2, 1951) SEMEN QUALITY 137 "count" alone, whether it be by "cc." or total count, as the sole factor in fertility. But it is just as true to say that "count" is important and indeed may still be the most important factor. If we use "count" as the sole criterion, is there any evidence arising from this study which would allow us to place a minimal level for fertility? We believe it is certain that if an arbitrary level is to be established it should be set well below the 60 million mark formerly accepted. In such a large group of fertile men there will always be a group of men whose semen quality is not good by any standards. If we admit 5 per cent of such cases in the fertile group and arbitrarily draw the line at that point (in this case close to 20 million/cc.) the most striking differences between the fertile and infertile men appear at this level. This is true also (but not in such a striking way) of motility and morphology in the two groups. If we were drawing a line at this level (to include 5 per cent of the fertile men) for motility, the dividing line would be 30 per cent active cells with a motility index of 50. Our line of demarcation for morphology using our standards of morphology would be about "55 per cent" normal forms. Putting this tersely, a semen specimen with 20 million cells/cc., 30 per cent active cells with a quality less than 2, and a morphology of 55 per cent normal forms would have a chance to produce conception. Actually, taking our fertile men at the 1-20 million level, most of them have better than 30 per cent active cells, better quality of motility and a "higher percentage of normal forms. We believe, therefore, that the 30 million/ cc. count level, rather than 60 million/ cc., is a much more realistic figure at which to consider sub fertility beginning. DISCUSSION DR. ERNEST PAGE, Berkeley, California: Dr. MacLeod has presented to this Society today the most complete, most thoroughly studied series of semen analyses that has been assembled by a single competent observer. We owe him a debt of gratitude for his prodigious amount of work, for it will prove invaluable for establishing standards of fertility among men. Dr. MacLeod's data on what he calls the "infertile" group of 800 men are quite consistent with our group of 800 men, whom we prefer to designate as "fertility unknown." The small group which we have labeled "fertile" is not a representative sampling, but rather corresponds to Dr. MacLeod's group of "infertile" men who produced conceptions. Here, again, our data are quite comparable except in respect to morphologic criteria. In looking over both sets of data, it has struck me that if we were to remove

24 138 MACLEOD [Fertility & Sterility from 5 to 15 per cent of the lowest counts, the poorest motilities, or the poorest morphologies from the 800 men of unknown fertility and then redistribute the remainder, we could make the fertile and the unknown groups appear identical. Does this mean that the differences between the two groups are due to the presence of from 40 to 120 infertile men in the unknown group? Even if we add to this the number of men with azoospermia, the total number is far below previous "guestimates" as to the percentage of infertile couples in which the male is responsible. I rather suspect that this will prove to be true, that something less than 20 per cent of husbands are responsible for infertile marriages. The much higher percentages quoted in the past may have been influenced by arbitrary and fictitious standards which Dr. MacLeod has shown to be far too high. While we both agree that previous standards were too high, I am a little surprised that he would even suggest new dividing lines between "normal" and "abnormal." I can't believe that there will ever be a dividing line except in one category, namely, "sperm present" or "sperm absent." When spermatozoa are present, there must be a mathematical chance for conception (though we might have to place one directly upon the ovum!). Perhaps we should begin to express what that mathematical chance is, even though we might have to make tentative assumptions. I am not so much concerned with the numerical values contained in any series as in trying to answer a query from a husband or from a practicing physician as to what an individual semen analysis means. Dr. MacLeod tells me that it may be another ten years before we can reply to such a question intelligently, but we are most impatient. Perhaps the answer will have to come from the veterinary inseminators of cattle or the inveterate inseminators of women. In the meantime, each of us-in our own peculiar fashion-attempts to formulate some sort of intelligent reply. How we do this should be one of the major concerns of this Society. Thanks to Dr. MacLeod, we have some admirable data from which the true interpretation may emerge. DR. ROBERT HOTCHKISS, New York City: May I emphasize one important detail of Dr. MacLeod's research. He took elaborate precautions to maintain a completely unbiased perspective when he undertook this work. He has remained completely unaware of the identity of the individuals on whom the semen analyses were done. At no time did he know whether the semen was procured from a member of the fertile or the infertile group. His margin of error in performing cell counts and morphological classification was scientifically determined and the work proceeded entirely without influences of any preconceived opinions. The enormous mass of statistical data has been processed by a trained biometrician who had no influence in the outcome, other than its mathematical accuracy. The meticulous care and strict scientific approach, coupled with the largest series of infertile and fertile marriages on record, documents this report as being the most authentic study to date. DR. MACLEOD, closing: This study, as I pointed out in the symposium last year, was begun about a year ago with the idea that we actually knew nothing of the fertile man; and by the fertile man I mean, the individual who is married, has normal marital relations, produces children in the normal way without having to to

25 Vol. 2, No.2, 1951] SEMEN QUALITY 139 consult a specialist as to why he can't do so. If you think about it for just a moment you will see that this is a population that we never see at all. You will remember also that many of our standards on the human male are actually based upon studies of males in infertile marriage, and therefore, may be misleading. This study was begun and controlled as well as any human could do it, I believe, though I would like suggestions from the floor as to ways of controlling it better. We already had in our files about twenty-five hundred cases of males in infertile marriage, but we decided to discard those completely and to start out fresh when we studied the fertile man so that we could study concurrently with the fertile man a new group of men in infertile marriage. Now, any time I used the word "infertile," in this talk it was in "quotes," because you must remember that all men who come for study in infertile marriage are not infertile. The other control in this study was that all of the observations should be made by the same observer so that there should be no diversity in the interpretation of the semen specimens. It was unfortunate that that observer had to be me, but I felt that I couldn't discuss the subject adequately later if I allowed anyone else to do morphology examinations or to assess the motility of the spermatozoa. All the fertility and morphology examinations done in this study have been done by me personally. The sperm counts were done by trained assistants. There is far less chance of the subjective element entering into counting the number of cells in the chamber than in enumerating the cells morphologically. To avoid further the subjective element, we arranged the study so that the observer did not know the source of the semen specimen examined by him. By so assigning whether it came from a fertile or "infertile" man-again I used the word "infertile" in quotes-the specimens were all prepared for motility and morphology examination by assistants so the observer did not know the specimen he was picking up. All the statistics that I presented to you this afternoon were obtained as objectively as anyone could obtain them..