The Male Factor in Fertility and Infertility. IV. Sperm Morphology in Fertile and Infertile Marriage. John Macleod, Ph.D., and Ruth Z. Gold, M.A.

Transcription

1 The Male Factor in Fertility and Infertility IV. Sperm Morphology in Fertile and Infertile Marriage John Macleod, Ph.D., and Ruth Z. Gold, M.A. I N PREVIOUS papers of this series we have compared semen quality in 1000 men of known fertility with that in 1000 men whose problem was infertile marriage. These studies comprised analysis of ejaculate volume, sperm counts, and motile activity and the relationship of each of these aspects of semen quality to the other. It remains for us to present the results on the fourth principal aspect, the morphology of the spermatozoa. Before doing so, we believe it is essential to survey the widely varied approaches to the examination of morphology and to the equally varied interpretations of the significance of morphology. To do so in extenso is impossible. There are as many different interpretations of morphology as there are authors, without general agreement as to the various cell types which constitute abnormal forms. We do not propose to present the views of the various proponents in detail but rather would refer readers to the published work of Cary, Williams, Moench, Hotchkiss, Harvey & Jackson, and Weisman as being representative of views in this troubled field. All of these workers agree that there is a relationship between abnormal sperm morphology and male infertility, with most taking the view that normal semen should contain no more than 20 per cent abnormal spermatozoa. Obviously, the classification of cells within this arbitrary criterion will vary with different observers inasmuch as a cell considered "abnormal" by one is not always classified as such by another. From the Departments of Anatomy and Obstetrics and Gynecology, Cornell University Medical College, New York. We are deeply grateful to Cornelius Vanderbilt Whitney for financial aid in this research. 394

2 Vol. 2, No.5, 1951] SPERM MORPHOLOGY 395 It will be impossible for us to make any reasonable analysis of morphology if we take the criteria of all observers as our basis of abnormality. In fact, we are not prepared at this time to classify any but the most distorted forms as truly "abnormal" cells in the sense that we deny the ability of any particular cell to fertilize the ovum. Until such time as we are able to witness the fertilization of a human ovum and to classify precisely the type or types of spermatozoa which are capable of doing so, we can never be in the position to state dogmatically that certain types (in terms of morphology) cannot. The best we can hope to do at this time is to show that semen specimens in which every quality but morphology is good and in which particular types of abnormal cells are abundant or predominate, fail to produce conception or cause habitual abortion or mi~carriage. We have shown 7 that there is a strong relationship between the quality of motile activity and fertility potential. There is a similar relationship between the percentage of active cells and fertility. This data bears out the intuitive belief that for a spermatozoon to fertilize an ovum it must have motile activity and, in addition, a particular quality of activity. It is natural, therefore, to examine a possible relationship between sperm morphology and motile activity. If it can be shown that spermatozoa of poor morphology at the same time have inherently poor or no motile activity then these cells can be eliminated from consideration inasmuch as they are not likely to reach the vicinity of the ovum. The net effect of poor morphology therefore would be to cut down the number of potentially fertile spermatozoa and thus lower the chances of conception. We feel that one of the basic weaknesses of sperm morphology examinations to date is that the classification of abnormal spermatozoa by the use of fixed and stained smears gives no indication whatsoever of the previous behavior of any particular cell in the ejaculate. For example, if any given semen specimen shows a high percentage of abnormal forms in the stained smear, does it follow that all of these cells showed good quality of motility in the original ejaculate? We can by no means make such an assumption (as Harvey and Jackson have pointed out so aptly). Nor is it an easy matter to examine motile spermatozoa in the fresh ejaculate and classify each one according to its morphology. It is true that one can study the inert cells to a certain extent and classify them. It is also possible in the wet preparation to show that certain cells of obvious abnormal morphology show sluggish activity but it is not

3 396 MaclEOD & GOLD [Fertility & Sterility possible to make a quantitative estimate of motile or inert cells in terms of their morphology. In spite of these limitations in technic, it should be possible in this study of large populations to show certain relationships between morphology and motility and between morphology and fertility if such relationships are present. We shall attempt to do so in the following analysis. TECHNIC Throughout this study we have deliberately chosen technics of such simplicity that any worker with experience and with limited facilities can use them. This rule should apply with equal force in preparation of the spermatozoa for morphologic examination. There is a wide variety of sperm staining technics in vogue, some of which are simple, some impossibly complex when large numbers of semen specimens have to be examined at anyone time. We have tested many of these procedures and have confined ourselves to one which combines speed and simplicity and which at the same time shows most of the characteristic morphologic characteristics of human spermatozoa with clarity. The technic is that of Kaufman which consists essentially of an air-dried smear (room temperature) fixed in 10 per cent formalin and stained with a simple hematoxylin. Its virtues are: (1) rapidity (the entire procedure takes less than three minutes); (2) a clear background (the mucoid elements of the seminal fluid do not take the stain); and (3) most of the structures of the spermatozoa are clearly delineated. In particular, this stain clearly outlines the vacuole formation which is so characteristic of the "head" portion of human spermatozoa. We have not found that the drying of the smear produces cellular distortion. This point will be discussed more fully later. One observer (the senior author) made all the morphologic examinations. The slides were prepared by an assistant and coded in such fashion that the observer did not know the class of individual (fertile or "infertile") from whom the semen originated. This objectivity has been maintained throughout the study. It has been our custom in the past to examine 300 cells on each smear for the morphologic classification. This was possible and desirable when more than one observer took part in the examinations. In the early part of this study, however, it became apparent that, on most days, the number of

4 Vol. 2, No.5, 1951] SPERM MORPHOlOGY 397 specimens to be examined imposed too much fatigue on the single observer if 300 cells were examined. It was decided to reduce the number to 100 but before doing so, an accuracy test was designed to determine the error associated with the 300 and the 100 cell examinations. The average standard deviation for 300 cells was about ± 3 per cent and for 100 cells, ± 6 per cent, using the "normal" (see below) sperm classification as the base line. Although the error involved in counting only 100 cells is twice that of covering 300, we do not feel the difference is sufficient to justify the tripling of labor involved in enumerating the larger number of cells. Throughout this study, therefore, all the morphologic analyses are based on the study of 100 cells. In classifying the various morphologic types, we have followed the criteria used in the laboratory for years, namely those laid down by Hotchkiss et al. Only two changes of consequence have been made. We have extended the classification of "small" cells to include spermatozoa of less than normal size (from one-third to one-half smaller than the normal "oval" form) but of otherwise normal morphology. We also have omitted the "round" classification inasmuch as we believe this type is relatively rare. When it is found, the chromatin content in proportion to head size is exaggerated to the point where the cells can be put in the "amorphous" class, the latter being a receptacle for all cells of bizarre shapes or structures. Our classifications, therefore, are six in number, as follows: oval (normal), large (megalo), small, tapering, anwrphous, and duplicate. The latter class includes cells with two or more heads on one tail, or one head on two or ~ more tails. We have omitted "immature" forms mainly because we believe truly immature spermatozoa such as the spermatid and the spermatocyte are rare inhabitants of the ejaculate and that if they are present in the ejaculate at any time they cannot be distinguished from certain extraneous cells such as pus and epithelial cells. We admit that certain cells we classify as "amorphous" may be "immature" but since we personally lack the knowledge or the criteria to put them in the latter class, the "amorphous" niche seems to us the appropriate place for them. We are aware that there will be disagreement with these criteria and that competent workers in this field may wish either to add other "abnormal" classes or to challenge our inclusion of certain cell types as "abnormal." All we wish to do at this time is to make clear what we consider to be devia-

5 398 MacLEOD & GOLD [Fertility & Sterility tions from "normal" morphology and to interpret the data according to these arbitrary criteria. An additional factor in the morphologic examination is our handling of semen specimens with low sperm counts (20 million/ cc. or less). We have found it necessary to centrifuge such specimens (1500 RPM) in order to get enough spermatozoa in the concentrate to make the stained smear. There is no evidence that centrifugation distorts the sperm morphology. RESULTS Figure 1 shows the relative frequency distribution (RFD) of "normal" cells in the fertile and "infertile" populations. Only 989 men are represented Cumulative Frequency % PERCENT NORMAL CEllS RnATlYE FREQUENCY DISTRIBUTIONS Fertile (,989C... ) Infertile (969C.5I5) "1.'= = 7 p, FIGURE 1. PERCENT NORMAL ails Relative frequency distributions of the percentage of morphologically normal cells in 989 men of known fertility and 969 men in infertile marriage. in the fertile group and 969 in the "infertile." The number deficiency in the fertile group is due simply to 11 missing morphologic examinations. Originally, in the "infertile" group, 90 morphology examinations were missing but for a different reason which must be explained. When this study was begun, the centrifuging technic was not employed to concentrate the spermatozoa in specimens where the sperm count was very low. In such

6 Vol. 2, No.5, SPERM MORPHOLOGY 399 cases, morphologic examinations were not done only because there was a lack of cells on the stained smears made from unconcentrated semen. Had we proceeded with the analysis on the basis of only 910 individuals in the "infertile" group, the general morphologic picture in the "infertile" group would have been distorted mainly because the number deficiency would have been preponderately in the "low sperm count" classifications. For example, of the 90 missing examinations, 59 were in the under 20 million/ cc. group. We replaced these 59 by taking a similar number from a new group of "infertile" men with corresponding sperm counts and motile activity. TABLE 1. Proportion Fertile by Percentage Normal Cells Normal cells (%) All cases < and over Signif = p <.Ol. Mod. Signif.01 < P <.05. Not Signif = p >.05. No. of cases in class Proportion fertile in class (%) Difference from 50.5% Signif Mod. signif Signif Signif Not signif Not signif Signif Signif Thus, the 59 morphologies added to the "infertile" group in this study are not included in the previous studies on volume, count, and motility. Studying the relative frequency distributions, the distinct differences between the two groups are apparent at the under 60 per cent normal level and at the level of 80 per cent normal and over. Only 9 per cent of the fertile group fall in the lower level as compared to 21 per cent in the "infertile" group. In contrast, at the upper "normal" level, 59 per cent of the fertile group are found compared to only 44 per cent of the "infertile" men. As in our studies of volume, sperm counts, and motility, there are distinct differences between the two groups in morphology. If we look at median values alone, the difference between 82 for the fertile group and 77 for the "infertile" group is not impressive, but the median values do not show the essential differences between the two groups. Similarly, the

7 400 MacLEOD & GOLD [Fertility & Sterility arithmetic means of 79 per cent (S.D. = 14 per cent) for the fertile group and 73 per cent (S.D. = 17 per cent) for the "infertile" group are simply figures which can be used for comparison with other data and throw little light on the true state of affairs. The differences in both the average and median figures are statistically significant. Table 1 presents the data in Fig. 1 distributed in such fashion that the relationship between sperm morphology and fertility is seen most easily. If we combine the fertile and "infertile" samples and classify them according to the percentage of "normal" cells, then if there were no relationship between morphology and fertility, the fertile group should contribute the Conception. (225 Co.es) No Conception. (652 Co.es) PERCENT NORMAL CEllS L 60% I=:=J 60-79% ~ 80-89'10~ 90-99%_ X. &: '1. 3 l' >.05 FIGURE 2. Relative frequency distributions of the percentage of morphologicaily normal ceils in 225 men in infertile marriage with a history of one or more conceptions, and in 652 men in infertile marriage who had never produced a conception. same relative number at each per cent normal level as it does to the total sample. For example, (Table 1) in combining the two groups, the fertile group contributes 50.5 per cent to the total sample (989 cases out of a total of 1958). If there were no relationship between morphology and fertility we would expect, therefore, that the fertile group would contribute approximately 50 per cent at each per cent normal level. That this does not happen is apparent from Fig. 1. At the level of less than 30 per cent normal forms the fertile group contributes only 22 per cent (instead of 50 per cent) to the total sample. Above this level, the contribution made by the fertile group rises fairly steadily until it reaches 60.9 per cent at the

8 Vol. 2, No.5, SPERM MORPHOLOGY per cent and over normal mark. Analyzing these contributions more carefully, we see that up to the 60 per cent normal level there are significantly fewer made by the fertile group whereas above the 80 per cent normal level, the fertile group contributes a significantly higher number. The real line of demarcation between the fertile and "infertile" groups so far as the lower limit of "normal" cells is concerned is at or under 60 per cent normal. The general picture of morphology in relation to fertility shown here is quite similar to the one found for motile activity.7 The relationship between morphology and motility is discussed below. Ferti'. c=:j FIGURE 3. /ohm/. ~ Average distribution of abnormal cells in the fertile and "infertile" groups. In our previous studies on sperm counts and motile activity we subdivided the "infertile" group so that any individual with a conception in his marital history (one-child sterility, a miscarriage or miscarriages, etc.) was arbitrarily considered as a fertile individual and removed from the "infertile" group. Thus, we have two new groups for comparison and we were able to show that for sperm counts and motile activity, the differences between these two groups were significant, though not to the same extent as the difference between the main fertile and "infertile" groups. We have made the same analysis for morphology (Fig. 2). Though there is a difference between the conception and "no conception" groups it is not statistically significant.

9 402 MaclEOD & GOLD [Fertility & Sterility Distribution of Abnormal Forms in the Fertile and Infertile Groups The average morphologic picture in the two groups is as follows: Fertile Percentage Infertile Oval Large 1 2 Small 8 9 Tapering 4 4 Duplicate 1 1 Amorphous 7 10 The most frequently occurring abnormal types are the "small" and the "amorphous." As we already have pointed out, for the normal forms the averages do not show striking differences between the two groups for the abnormal cells. Figure 3 shows the average distributions of all the "abnormal" cells found in the combined groups. The largest contributions to the "abnormal" population are made by the small and the amorphous forms. However, while the two groups contribute roughly the same amount in the "small" cate- TABLE 2. Proportion Fertile by Abnormal Cell Types Percentage Large cells Small cells Tapering cells Duplicate cells Amorphous cells Pro- Pro- Pro- Pro- Pro- No. of portion No. of portion No. of portion No. of portion No. of portion cases fertile cases fertile cases fertile cases fertile cases fertile All cases } and over } } gory, the "infertile" group contributes significantly more than half the "amorphous" cells. There are about equal contributions from the two groups of "duplicate" and "tapering" forms. Although few in number the "large" cells come mainly from the infertile group. Table 2 shows the proportion of cases contributed by the fertile group to the various levels of the five "abnormal" cell types. There is no conclusive pattern in the small, tapering, or duplicate forms. However, there is a

10 Vol. 2, No.5, 1951] SPERM MORPHOLOGY 403 dramatic decrease in the number of cases from the fertile group contributing to the higher levels (proportions) of both large and amorphous forms. Relationship Between Abnormal Forms It is of interest to determine if there are any significant relationships between the various types of abnormal forms and, if so, if the relationship patterns are the same in both fertile and infertile groups. If we take each "abnormal" class and relate it to every other class we find in the fertile group that there are significant relationships between amorphous and "small" cells, between amorphous and "duplicate" and between amorphous and "large" cells. This means simply that where one finds a small percentage of amorphous forms one can expect to find relatively few of the other abnormal types. Studying the "infertile" group in similar fashion we find that in addition to the relationships noted above in the fertile group, the amorphous cells are related to the tapering forms, the tapering to the large and there is an inverse relationship between the "small" and "large" types. The latter is the only significant inverse relationship we have found. We give these details merely to lay the groundwork for an analysis of patterns of spermatogenesis which inevitably must be considered. We have not presented the analytic data which support the above findings inasmuch as twenty extensive tables would be required. Relationships of Morphology to Ejaculate Volume Throughout this study as each characteristic of semen quality is analyzed, we propose to investigate the relationship of each quality to the others if any such relationship exists. vve have completed the analysis of ejaculate volume,6 of sperm counts,s and of motile activity7 and the relationship between these. We are now in the position to relate our findings on morphology to the other primary characteristics of the ejaculate. If, as our criterion of good morphology, we take 80 per cent or over normal forms, there is a decreasing number of good morphologies with increasing ejaculate volume in both fertile and infertile groups. But in the fertile group the proportion of cases with under 60 per cent normal cells increases above the 6.0/ cc. volume level, a point of significance not found in the "infertile" group which, at the under 60 per cent normal level showed no consistent relationship with volume.

11 404. MaclEOD & GOLD [Fertility & Sterility Relationship of Spermatozoan Counts to Morphology In both fertile and infertile groups there is a Significant relationship between "per cent normal" cells and sperm count/ cc. (it is immaterial whether sperm count/ cc. or total count is used). Up to a count level of 100 million/ cc., there is a rise in the average percentage of normal cells with increasing count. Above the 100 million/ cc. level, the average "per cent normal" remains about the same. Figure 4 shows the distribution of "per cent normal" cells in both groups for various count/ cc. levels. In both groups the improvement in morphology with increasing counts is obvious. But, at every count level the morphology of the fertile group is superior to that of the infertile group. In fact, the morphology of the under 20 million/ cc. class of the fertile group is superior to that of the million/ cc. class of the "infertile" group. The most revealing differences between the two groups are seen at the low count ( under 20 million/ cc. ), poor morphology (under 60 per cent normal cells) levels. For example, in the fertile group 44 per cent of the cases with less than 20 million/ cc. had 80 per cent or better cells of normal morphology compared to only 17 per cent of the infertile group. At the same count level (under 20 million/ cc.) and considering the poorer morphologies, 23 per cent of the infertility group had under 40 per cent cells of normal morphology in contrast to only 7 per cent in the fertile group. Other comparisons of interest not shown in the figure are: 1. Of the cases with less than 60 per cent of cells with normal morphology, 10 per cent of the fertile group compared with 33 per cent of the infertile group also had counts of less than 20 million/ cc. 2. Less than 1 per cent of the fertile group compared with 7 per cent of the infertile had both subnormal counts (less than 20 million/ cc.) and morphology (less than 60 per cent normal cells). 3. Twelve per cent of the fertile group compared with 30 per cent of the infertile group had either subnormal counts or subnormal morphology. Relationship of Morphology to Motility In both the fertile and "infertile" groups the percentage of active cells rises Significantly with rising percentages of morphologically normal cells. Figure 5 shows the comparative "per cent active" cells for varying levels of "per cent morphologically normal cells" in both groups. At all morphology

12 Count per CC t 20 M Count por CC M Count per CC M Count per CC 80M r < o... z o u. 0() u. en... m '" ~ ~ o '"... ::t... o o G') -< FIGURE 4. % Normal Cells less thlll 60% c::::j 60-79% mmmi 80 89% r22zi 90-99% _ Relative frequency distributions of the percentage of normal cells at various count per cc. levels in the fertile and "infertile" groups. ~

13 ~ lass than 60% Normal 60-19% Normal.0 19 % Normal % Normal ~ D n,... m o C 11" C) o c FIGURE 5. % Active Cells lasl than 40%CJ "'-55% mm 60-65% ms:i 70%,1_ Relative frequency distributions of the percentage of active cells at various "per cent normal cell" levels in the fertile and "infertile" groups.."... "< 11" en <

14 Vol. 2, No.5, 1951] SPERM MORPHOLOGY 407 levels the "per cent active" cells of the fertile group is superior to that of the infertile group. Furthermore, the per cent activity of the poorest morphologic class in the fertile group as indicated in Fig. 5 (under 60 per cent normal cells) is at least as good as that of the per cent normal class of the infertile group. In comparing morphology with quality of motility, the same general relationships are found. Since we already have shown 7 that there is a very close relationship between "per cent active" cells and quality of motility it perhaps is not surprising that this propinquity between the two aspects of motility is not disturbed when each is compared to cell morphology. The implications of these findings on morphology are discussed below. DISCUSSION The various authorities in the field of semen analysis are agreed that sperm morphology is an important factor in fertility, if only because they insist that a morphologic examination of the spermatozoa be done in every case. There are those who claim that sperm morphology is the all-important factor in male fertility and have placed well-defined limits in terms of percentage of abnormal forms below which, irrespective of other aspects of semen quality, a man is considered sterile. For example, Moench, one of the foremost proponents of sperm morphology as a vital factor, states that a maximum of 20 per cent abnormal forms is found in the semen of fertile men and that when this figure exceeds 25 per cent, sterility is probable. Williams, whose studies on bull and human sperm morphology are equally well known, is more liberal in his approach and considers that where the percentage of abnormal forms exceeds 40 per cent, the semen of that individual should be considered "sterile or essentially sterile." As we have pointed out earlier in this paper, if any such criteria of male fertility are to be adopted, there must be complete agreement as to what constitutes an "abnormal" spermatozoon. We are by no means sure that this agreement h;;-b;:n rea~hed, or that it ever will. But if we study the reports of various authors who, presumably, use the same criteria of abnormality we find there is general agreement on average figures for normal sperm morphology. As we have already said, we have modified the Hotchkiss criteria in the present study by introducing the "small" classification, one which includes spermatozoa which are one-third to one-half smaller than the average but are of otherwise "normal" morphology. Secondly, we have omitted the

15 408 MaclEOD & GOLD [Fertility & Sterility "round" classification of Hotchkiss mainly because such cells are relatively rare and when they are present show abnormalities in chromatin content which places them in our "amorphous" class. This would explain why our present average for "normal" cells (79 per cent) for our fertile group is about 10 per cent lower than those recorded by Hotchkiss et al. for 200 men of known fertility and 11 per cent lower than those reported by MacLeod and Heim for 100 presumably normal young (unmarried) men. Similarly, in comparing our present averages for "normal" cells with those of Falk and Kaufman who also modified the Hotchkiss criteria by adding a classification for "small" cells, our average figures are 9 per cent lower. This difference is accounted for mainly by the fact that we are more rigorous in that we classify more cells of the "small" variety. Page and Houlding followed the Hotchkiss method in their study of 1000 semen specimens and also report a higher average for "normal" cells, but while they do not give a detailed description of the various cell classifications they followed, they do say that "... in borderline or doubtful cases, sperm heads were classified as normal." We interpret this statement to mean that they probably included all the cells in our "small" classification in their "normal" group, which would account for the major difference in our average figures. A further point in relation to the findings of Falk and Kaufman in relation to ours lies in the "amorphous" cell classification. Their average figures in this class for 100 fertile men is 2.1 per cent compared to our figure for 1000 fertile men of 7 per cent. Such a wide discrepancy cannot be explained by the difference in size of our populations or by their more rigorous selection of their subjects. It must be due to a difference in interpretation of what constitutes an "amorphous" spermatozoon. This point is of considerable importance because it shows that two different observers using the same method for preparation and staining of the spermatozoa and apparently the same criteria, can come to different conclusions. The point has further importance so far as this study is concerned since in the "amorphous" class lies one of the major differences between our fertile and "infertile" men (so far as sperm morphology is concerned) lies. We feel, therefore, that when two groups of observers studying essentially the same populations and using essentially the same methods cannot agree, there is not much likelihood of agreement among observers using more divergent criteria. This is not to say that we are right and others wrong but merely that there is considerable difference of opinion. It will

16 Vol. 2, No.5, 1951] SPERM MORPHOLOGY 409 be obvious then that the differences in morphology observed by us in the fertile and "infertile" populations are based only on our interpretation of "abnormal" cells. The data presented here show that as in the sperm counts 8 there are sharp distinctions between fertile and "infertile" men which are apparent at definite levels of "abnormal" morphology. Using our criteria, there appear to be three principal levels at which the chances of "normal" fertility are less than, equal to, or greater than expected. These levels respectively are under 60 per cent "normal" forms, between 60 and 80 per cent and above 80 per cent "normal" forms. These conclusions are definite when we take morphology alone as our criterion of fertility but they attain more significant proportions when we relate the morphology findings to the other aspects of semen quality, particularly sperm counts and motile activity. Most authorities agree that there is a relationship between the various aspects of semen quality, e.g., that as the sperm count decreases, the morphology and motility show increasing abnormality. The latter conclusion has been amply demonstrated in studies of infertile men but the importance of the present study lies in the fact that while it is true that the same general principle holds in the semen of fertile men, it does so to a much lesser extent than in the "infertile" group. Close study of Fig. 4 shows clearly that sperm morphology at all sperm count levels is better in the fertile group than in the "infertile." But what is more significant is that at the lower count levels (from under 20 million to 80 million/ cc.) the fertile group maintains the same proportion of cases with 80 per cent or more "normal" cells whereas in the "infertile" group at the corresponding count levels the proportion of cases with the same number of normal cells more than doubles. As further emphasis of this important point, the morphology of the fertile group at the lowest count level (under 20 million/ cc.) is, if anything, better than that of the "infertile" group at the million/ cc. level. This would suggest that morphology is of considerable importance, particularly since, as the data also show, there is a rising potential of fertility with increasing "goodness" of morphology. But we already have demonstrated 7 that there is a similar rise in fertility potential with increasing quality of motile activity. Analyzing this further and relating morphology to motile activity (Fig. 5) we find that though these two aspects are significantly related in both the fertile and "infertile" groups, again, as in the case of the count-morphology comparison, the relationship is not the same in both groups. At the lower

17 410 MaclEOD & GOLD [Fertility & Sterility "per cent normal" cell levels (from less than 60 per cent up to 80 per cent "normal" cells) in the fertile group, the motility (either in terms of "per cent active" cells or quality of motility) does not improve to the same extent in both groups. For example, when the percentage of normal cells increases from under 60 to per cent, the proportion of cases in the fertile group with 60 per cent or more active cells increases by 6 per cent ( from 45 to 51-a relative increase of 13 per cent). Whereas in the "infertile" group, the corresponding number of cases increases by 14 per cent (from 25 to 39-a relative increase of 56 per cent). In addition, the motility of the under 60 per cent normal class in the fertile is at least as good as the per cent normal class of the infertile group. Falk and Kaufman feel that "... good morphology, although not absolutely necessary for fertility, is perhaps a more stabilizing influence than any other factor of the semen." We cannot agree completely with them inasmuch as we feel that while good morphology undoubtedly is a stabilizing factor, motile activity plays an equally important role. W~ have reached a point in this analysis at which we are in a l2.q,sij:ion tp relate all aspects of semen. guality to fertility, and to determine, if possible, ~ 'as12ect is more important,. The previous studies on sp;:id counts S and motile activity7 suggest minimal standards for "normal" fertility of 20 million/ cc. for counts and "40 per cent active" cells (with a quality of at least "2") for motility. The data presented here point to a minimum requirement of 60 per cent morphologically normal cells. In the case of all three qualities, the approach has been the same. At each level of count, motility, and morphology, the proportion of cases that come from the fertile group in our combined sample of observations has been compared with the proportion contributed to the total sample by the fertile group. If all the cases in the fertile group were of equal fertility and all in the infertile group really infertile, and assuming the two groups to be representative of the populations from which they come, this approach would be quite reasonable. If the above assumptions held true, then the proportion fertile in the sample would be closely related to the chances of fertility in the population as a whole. An increase in the proportion fertile would imply an increase in the chances for fertility, etc., although the particular proportions and chances would not necessarily be equal. The assumptions of equal fertility and infertility in the two groups, we know, are fallacious. The assumption of representativeness is more reason-

18 Vol. 2, No.5, SPERM MORPHOLOGY 411 able in view of the large number of observations involved. The next major step in this study will be an attempt to correct for the unequal fertility within each of the two groups (fertile and "infertile") by taking into consideration the fertility of the wife and the duration of infertility. In spite of the weaknesses noted above, we believe it not too unreasonable to continue along the lines indicated above and combine the findings on counts, "per cent active" cells and "per cent normal" cells, since the data show some consistent trends.. We define the various levels of each semen quality as "poor," "adequate," or "good" as follows: poor: the proportion contributed by the fertile group at this level is significantly less than the proportion fertile in the total sample. adequate: the proportion fertile at this level is about equal to the expected proportion. good: the proportion fertile is significantly greater than expected. The only semen quality which did not show distinct "adequate" and "good" levels is the count. We introduce these count levels arbitrarily for the sake of convenience. The three levels for the three qualities then are as follows: Poor Adequate Good Count! cc. in millions < % Active cells < % Normal cells < Ignoring the particular semen qualities involved there are ten possible situations for each specimen ranging from all three qualities poor to all three qualities good. The 1577 individuals in both groups whose motility was observed within five and one-half hours and whose morphology was examined have been studied and the results are presented in Table 3. The table shows that as the number of poor qualities decrease and the good ones increase, the contribution of the fertile group to the total number in each category rises from 6.5 per cent for the case where count, motility (per cent active), and morphology are all poor to almost ten times as much (61 per cent) for the case where all three are good. A question that naturally arises concerns the relative importance of the three semen qualities-is anyone of them of outstanding importance? For example, line 2 has three possible ways of arising: (1) count poor, morphology poor, per cent

19 412 MaclEOD & GOLD [Fertility & Sterility active adequate, (2) count poor, per cent active poor, morphology adequate, or (3) per cent active poor, morphology poor, count adequate. Taking all three together we find 14 per cent of such cases to come from the fertile group. Examining the three situations from which this figure comes the proportion fertile is (1) 12.5 per cent, (2) 15 per cent, (3) 15 per cent. In TABLE 3. Proportion Fertile by Semen Quality in Terms of Various Combinations of (1) Sperm Counts, (2) Percentage Active Cells, (3) Morphology Number of qualities Number of Percentage Difference Poor Adequate Good cases fertile from 46.0% ALL CASES Signif Signif Not signif Signif Signif Signif Not signif Not signif Not signif Signif The 3 semen qualities are defined as POOf, adequate, and good as follows: Count/cc. % active cells % normal cells Poor < 20m/cc. < 40 < 60 Adequate 20-39m/cc Good 4Om/cc other words it makes little difference which quality is adequate when two of them are poor. Breaking down all the classifications similarly yields no consistently outstanding quality either as a deficiency or as a compensation. In one case (line 4) the count/ cc. seemed to be more important than either of the other two qualities as the deficiency. V sing the relation of the proportion fertile for each classification to the proportion fertile for the entire group (46 per cent) as a criterion Table 3 suggests that semen quality is poor as long as one quality is poor, it is adequate when there are no poor qualities, and good where all three are good, the poor and adequate showing some variation within those designations. Some comparisons between the fertile and "infertile" groups not readily seen from the table are of some interest:

20 Vol. 2, No.5, 1951] SPERM MORPHOLOGY 413 Quality of specimen All three qualities poor All poor or adequate (none good) At least one poor None poor None poor but at least one good All good Fertile Percentage Infertile The evidence we have presented to date points to the importance of all aspects of semen quality, and to the necessity for a thorough examination of the latter at all times. So far, we have not considered the role of the female partner and the possible effect of her gynecologic history on the standards we are attempting to establish. This analysis is in progress with every indication that what we have said of semen quality in relation to fertility will hold and, indeed, may be strengthened. Nor have we considered semen quality, particularly morphology, in relation to miscarriage, habitual or otherwise but we have found no suggestion in our data that any such relationship exists. These studies will be published soon. Lastly, all of the analyses point to motile activity and morphology as being "compensating" factors for low spermatozoon counts. We are not willing at this time to single out either factor as more important. Rather do we believe that there is a strong relationship between morphology and motile activity in the sense that cells of poor morphology are likely to have poor motile activity. The converse need not necessarily be true. SUMMARY 1. The morphology of human spermatozoa III fertile and "infertile" populations has been analyzed in terms of ability to produce conception. 2. The sperm morphology of the fertile group consistently is better than that of the "infertile" group. 3. There is a rising fertility potential with increasing quality of morphology. 4. The quality of morphology is related both to the sperm count and motile activity, the quality decreasing with lowering of the sperm count and decrease in motile activity. 5. All primary aspects of semen quality (count, motility and morphology) are analyzed in various combinations to determine if anyone aspect is most

21 414 MacLEOD & GOLD [Fertility & Sterility important in fertility. The conclusion is that all are important with no one factor exceeding another. REFERENCES 1. Cary, W. H.: New York State J. Med. 30:131, Falk, H. C., and Kaufman, S. A.: Fertility and Sterility 1:489, Harvey, C., and Jackson, M. H.: Lancet 2:99, Hotchkiss, R. S., Brunner, E. K., and Grenley, P.: Am. J. M. Sc. 196:362, Kaufman, S. A.: Human Fertility 11:3, MacLeod, J.: Fertility and Sterility 1:347, MacLeod, J., and Gold, R. Z.: Fertility and Sterility 2:187, MacLeod, J., and Gold, R. Z.: J. Urol., in press. 9. MacLeod, J., and Heim, L.: J. Urol. 54:474, Moench, G. L., and Holt, H.: Am. J. Obst. & Gynec. 22:199, Page, E. W., and Houlding, F.: Fertility and Sterility 2:140, Weisman, A. 1.: Spermatozoa and Sterility. New York, Paul B. Hoeber, Inc., Williams, W. W.: Trans. Am. Soc. Study of Sterility 139, 1946.