Sexual arousal and the quality of semen produced by masturbation

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1 Human Repoduction vol.11 no.l pp , 1996 Sexual aousal and the quality of semen poduced by mastubation J.H.van Roijen 14 ' 5, A.K.Slob 4, W.L.Gianotten 2, G.R.Dohle 1 ' 3, A.T.M.van de Zon 2, J.T.M.Veebug 1 ' 4 and R.F.A.Webe 1-4 'Depatments of Andology, gynaecology and 3 Uology, Univesity Hospital Rottedam, Dijkzigt, ^Depatment of Endocinology and Repoduction, Faculty of Medicine and Health Sciences, Easmus Univesity, Rottedam, The Nethelands ^ o whom coespondence should be addessed The influence of sexual aousal on the quality of semen poduced by mastubation was investigated. One goup of 29 patients efeed to ou andology outpatient clinic (goup A) and one goup of 14 healthy potential spem donos filled out a questionnaie afte having poduced two semen samples, at least 1 month apat, by mastubation. Changes in questionnaie scoes between fist and second visit wee compaed with changes in semen chaacteistics between those two occasions to identify statistically significant coelations. A second goup of 23 subfetility patients (goup B) wee asked to poduce a semen sample by mastubation in a designated oom at the hospital without additional sexual stimulation, and a second sample while viewing a sexually explicit video. Diffeences in questionnaie scoes and semen chaacteistics obtained with visual eotic stimulation (VES) and without VES wee analysed. In goup A, the change in sexual aousal and change in intensity of ogasm coelated with change in semen volume ( = 038, < 0.05; = 0.48, < 0.01 espectively). In healthy donos and goup B, howeve, no such coelation was found. With VES in goup B, significantly highe scoes wee given fo 'feeling at ease/elaxed' ( < 0.01), 'sexual aousal' ( < 0.001), 'quality of eection' ( = 0.01), 'intensity of ogasm' ( < 0.05), 'satisfaction afte ogasm' ( < 0.05), and 'ease with which ogasm was achieved' ( < 0.001) with VES compaed to without VES. Thee was no statistically significant impovement in semen quality with VES compaed to without VES. It is concluded that sexual aousal has no significant influence on the quality of an ejaculate poduced by mastubation. On the othe hand, poviding a patient with a sexually stimulating video is obviously a facultative facto when the patient 'has to' poduce a semen sample fo analysis. The use of visual eotic stimulation is ecommended when patients and donos have to poduce a semen sample in the uninviting suoundings of a fetility clinic Key wods: mastubation/semen quality/sexual aousal Euopean Society fo Human Repoduction and Embyology Intoduction The vaiability of a man's semen chaacteistics ove a given length of time poses a poblem fo clinicians dealing with male fetility (Read and Schienen, 1978; Schwatz ea/., 1979; Bake et ai, 1981; oland et al., 1985; Mallidis et ai, 1991). It has been well documented that a single semen sample gives insufficient infomation about an individual's spem poduction, pompting the Wold Health Oganization (WHO) to ecommend the analysis of at least two semen samples in the diagnostic evaluation of a subfetile patient (WHO, 1992). Fo fetile men, some investigatos pefe to analyse at least thee samples because of the even geate inta-subject vaiations in semen chaacteistics (oland et al., 1985). A numbe of factos significantly influence the quality of an ejaculate, such as abstinence (Schwatz et ai, 1979), ecent and pesent disease (MacLeod, 1951; Buch and Havlovec, 1991), cetain medications, and the cicumstances unde which the sample is poduced (Zavos, 1985; Zavos and Goodpastue 1989; Sofikitis and Miyagawa, 1993; Zavos et ai, 1994). In addition, it has been suggested that the sample-to-sample dispaity in the epoted quality of an individual's semen may be the esult of questionable accuacy of the analysis itself, especially when pefomed by inexpeienced hands (Jequie and Ukombe, 1983). Although the above mentioned conditions clealy contibute to vaiations in the esults of semen analyses, studies that stictly contol fo these paametes nevetheless obtain a substantial within-subject vaiation fo spem concentation, motility, mophology and semen volume (Read and Schienen, 1978; Bake et al., 1981; Mallidis et ai, 1991). A numbe of epots have indicated that semen samples obtained by coitus, using a special seminal collection device, ae qualitatively supeio to samples obtained by mastubation with espect to volume, spem concentation, spem motility, and even spem mophology (Zavos, 1985; Zavos and Goodpastue, 1989; Sofikitis and Miyagawa, 1993). One could speculate that duing coitus inceased sexual aousal, with subsequently a moe intense ogasm, esults in a bette semen sample. Since the diffeences in semen quality between die samples obtained by coitus vesus mastubation ae consideable, one could futhe speculate that diffeences in sexual aousal and intensity of ogasm might also contibute to the within-subject vaiations in semen quality in ejaculates obtained by mastubation. The objective of the pesent study was to ascetain whethe vaiations in sexual aousal and intensity of ogasm, duing mastubation, ae coelated with vaiations in semen quality in patients and healthy spem donos. In addition, we investigated whethe actively inceasing sexual aousal in subfetile patients, 147 Downloaded fom on 11 Febuay 2018

2 J.H.van Roijen et al using visual eotic stimulation (VES), can be used to impove thei semen quality. Mateials and methods atients All patients wee ecuited fom ou andology outpatient clinic. Fo analysis duing the initial sceening, patients outinely poduce two semen samples, at least 1 month apat, afte a peiod of abstinence of 3-7 days. In the pesent study, two goups of patients wee asked to povide two semen samples by mastubation. Goup A (n = 29 patients) was asked to complete a questionnaie afte each sample was poduced. They wee fee to choose thei pefeed suoundings (at home o in the clinic) and sexual stimuli. Goup B (n = 23 patients) poduced both semen samples at the hospital, in a oom especially designated fo this pupose. In this goup, at the fist occasion, no extenal sexual stimuli (including the patient's patne) wee pesent. At the second occasion, patients wee povided with an eotic video with specific instuctions fist to view the video fo 3 min befoe commencement of mastubation, and to keep watching until ejaculation. atients wee asked to complete a questionnaie following the poduction of each sample. Donos A total of 14 healthy men who volunteeed to donate semen fo ou atificial insemination pogamme paticipated. All poduced two semen samples at the hospital, to detemine thei eligibility as potential semen donos. Afte each sample was poduced, a questionnaie was filled out. Questionnaie and video film All paticipating men filled out identical questionnaies. atients who wee exposed to the eotic video wee also asked to what degee they found the video sexually stimulating. The questionnaie assessed subjective sexual aousal and genital esponses. aticipants wee asked whethe they felt at ease/elaxed, whethe they wee sexually aoused, how they ated thei eection, how they ated the intensity of ogasm, how easily ogasm was eached, and how satisfied they felt afte ogasm. Each item was scoed on a 10 cm analogue scale, whee (0) was the lowest ating and (10) the highest. In addition, the peiod of sexual abstinence was ecoded. A sexually aousing video, outinely used in the psychophysiological sceening of men with eectile poblems (e.g. Rowland and Slob, 1995), was selected fo viewing by goup B. Semen analysis All semen analyses wee pefomed within 120 min of ejaculation by two well tained technicians, who wee unawae of the esults of the questionnaie and whethe an eotic video had been povided Afte complete liquefaction, semen volume was estimated using a gaded syinge. Concentation and pogessive motility scoes wee estimated in duplicate, using the same Makle counting chambe fo all samples to contol fo possible inte-chambe diffeences. If the duplicate esults diffeed by moe than 10%, a thid analysis was pefomed, and the thee esults aveaged. ogessive motility was defined as the pecentage of spematozoa swimming at least 5 um/s (WHO gade a + b; WHO, 1992). Mophology was scoed by one technician, using the stict Kuge citeia (Kuge et al, 1986). Mophology is not outinely scoed fo semen donos, so this infomation was not available fo evaluation. The coefficient of vaiation (CV) fo concentation measuement of a semen sample of 25 X 10* spematozoa/ml was 12%. The CV fo a sample with a mean pogessive motility of 359b was 16%, and the CV fo a sample of 12% nomal mophology (stict citeia) was 14%. Statistical analysis To study the inteaction of the epoted subjective paametes with the esults of the semen analyses, the following calculations wee made: the esults (of the questionnaie and the semen analysis) of the fist visit wee subtacted fom those of the second visit. Thus, the esulting numbe was a measue of change in that paamete (A) fom fist to second visit. We then coelated (Speaman's test) the A-values of the subjective scoes with the A-values of the semen analysis esults. Fo n = 25, the powe was 90% to detect coelations of 0.6 at a = Fo goup B, diffeences between the esults obtained at the fist and second visits wee statistically tested using Wilcoxon's signed ank test fo paied samples. All data wee analysed with the Statistical ackage fo Social Studies (SSS) fo Windows vesion 6.0. Results Goup A The mean age of the patients was 32.7 (ange 25 48) yeas. Duing poduction of the fist semen sample, 13 patients epoted using eotic fantasy, five had thei patnes pesent, thee used eotic liteatue, one used an eotic video and seven used 'nothing' as a sexual stimulant. Vitually all patients made use of the same sexual stimulant duing poduction of the second sample, with the exception of two patients who changed fom 'nothing' to fantasy on the second occasion, one patient who had his patne pesent on the fist occasion but epotedly used 'nothing' the second time, and one patient who used fantasy the fist time but used eotic liteatue duing the second time. Compaed to the fist ejaculate, a modest but significantly highe level of sexual aousal was epoted duing poduction of the second sample ( = 0.04). No othe subjective scoes and no semen paametes wee statistically significantly diffeent between fist and second visits (Table I). Scoes given on the questionnaie duing the fist visit wee analysed fo coelations with those given duing the second visit. Stong coelations wee found fo sexual aousal and quality of eection ( = 0.84, < 0.001; = 0.84, < espectively). Semen chaacteistics, in paticula volume, concentation and total numbe of spematozoa pe ejaculate, measued in the fist ejaculate wee also stongly elated to those measued in the second sample ( = 0.85, < 0.001; = 0.86, < 0.001; = 0.82, < espectively). In Table II, the coelation coefficients and thei -values ae shown between the changes in questionnaie scoes and the changes in vaious semen chaacteistics fom fist to second semen sample. Only A-sexual aousal and A-intensity of ogasm wee positively elated to A-semen volume ( = 0.38, < 0.05; = 0.48, < 0.01 espectively). A negative coelation was found between A-satisfaction and A-motility ( = -0.04; = 0.05). All othe changes in semen chaacteistics, fom fist to second ejaculates, wee independent of the changes in subjective paametes epoted in the questionnaies. In addition, in this goup of patients, the peiod of abstinence was not elated to any of the semen chaacteistics. 148 Downloaded fom on 11 Febuay 2018

3 Sexual aousal and semen quality Table I. Mean (± SEM) questionnaie scoes month apat and semen chaacteistics of ejaculates poduced by goup A and potential donos on two occasions at least 1 Questionnaie atient goup A (n = 29) Donos (n = 14) Sample 1 Sample 2 Coelation coefficient Sample 1 Sample 2 Coelation coefficient At ease/elaxed" Sexual aousal* Quality of eection* Intensity of ogasm* Ease with which ogasm was achieved* Semen volume (ml) Concentation (X10 6 spennatozoa/ml) Total spematozoa (X10 6 pe ejaculate) Motility (%) c Mophology (% nomal) d 5.7 ± ± ± ± ± ± ± ± ± ± ± ± ± ii 0.37 b 7.7 dt it it it t it : t it t it O ' ' ' M ± ± ± ± ± ± ± ± ± ± ± 7.0 NA 6.4 : t : t 6.8 : t : t : t 0.6O 4.9 : t i: : t : t : t : t 7.2 NA ' O Scoed on a 10 cm analogue scale (0 = not at all; 10 = vey much). Significantly diffeent fom sample 1 ( = 0.04; Wilcoxon). ^ade a + b. d Stict citeia. ' < (Speaman). 2 < 0.01 (Speaman). 3 < 0.05 (Speaman). NA = not assessed. Table II. Coelation of changes in scoes on the questionnaies with changes in semen paametes, between ejaculates poduced on two occasions at least 1 month apat, of 29 patients (goup A) who had poduced the two semen samples unde identical conditions (Speaman) Change in: (visit 2-visit 1) Concentation (X10 6 spematozoa/ml) Total spematozoa (X10 6 pe ejaculate) Motility % (gade a + b) Mophology 1 ' (% nomal) T At ease/elaxed* Sexual aousal* Quality of eection* Intensity of ogasm* Time to ogasm (min) < < Scoed on a 10 cm analogue scale. "Stict citeia. Donos Downloaded fom on 11 Febuay 2018 The mean age of the potential donos was 25.0 (ange 20-31) yeas. Nine potential donos epoted using eotic fantasy as a sexual stimulant duing poduction of the fist semen sample, two had thei patnes pesent, one used eotic liteatue, and two epotedly used 'nothing'. All potential donos essentially used the same sexual stimulant fo the poduction of the second semen sample, with the exception of the two who had thei patnes pesent the fist time and who used fantasy as a sexual stimulant duing the second visit In this goup also, no diffeences in mean questionnaie scoes o mean semen chaacteistics between the fist and second ejaculate wee found (Table I). As with goup A, thee wee significant coelations between questionnaie scoes given at the fist visit with those given on the second visit, with the exception of sexual aousal (Table 1). The quality of eection was especially highly coelated between fist and second visits ( = 0.808, < 0.001). Likewise, the semen chaacteistics measued in the fist sample demonstated a significant elationship to those of the second sample, although the coelation coefficients wee lowe compaed to those obtained in goup A. In Table m, the coelation coefficients and thei -values ae shown between the change in questionnaie scoes and change in semen chaacteistics between fist and second visit. All changes in semen chaacteistics, fom fist to second visit, wee independent of the epoted questionnaie scoe changes on those occasions. atient goup B The mean age of goup B was 32.1 (ange 24-42) yeas. The mean questionnaie scoes, and the mean semen chaacteistics fo the fist visit (no VES) and the second visit (with VES) ae shown in Table IV. With VES, patients epoted to be significantly moe at ease ( < 0.01), epoted a highe degee of sexual aousal ( < 0.001), a moe igid eection ( < 0.01), a moe intense ogasm ( < 0.05), and wee moe satisfied aftewads ( < 0.05). In addition, with VES, ogasm was eached with geate ease ( < 0.001). The mean peiod 149

4 J.H.van Roijen et at Table HI. Coelation of changes in questionnaie scoes and changes in semen paametes, between fist and second ejaculation, of 14 healthy spem donos who poduced the two samples unde identical conditions (Speaman) Change in: (visit 2-visit 1) Concentation (X10 6 spematozoa/ml) Total spematozoa (X10 6 pe ejaculate) Motiliy % (gade a + b) At ease/elaxed* Sexual aousal* Quality of eection* Intensity of ogasm* Time to ogasm (min) Scoed on a 10 cm analogue scale. Table IV. Compaison of scoes on questionnaie and semen paametes fom 23 patients (goup B) who poduced the fist semen sample without visual eotic stimulation (VES) and the second sample with VES Mean (± SEM) scoes at fist Mean (± SEM) scoes at second Significance of diffeence b ejaculation (without VES) ejaculation (with VES) At ease/elaxed* Sexual aousal* Quality of eection* Intensity of ogasm* Ease with which ogasm was achieved* Concentation (X10* spematozoa/ml) Total spematozoa (X10* pe ejaculate) Motility % (gade a + b) Mophology (% nomal) ± ± ± ± ± ± ± ± ± ± ± ± ± : t : t 6.3 : t : t : t : t : t : t : t : t = t 2.63 < 0.01 < = 0.01 < 0.05 < < 0.05 = 0.82 = 0.63 = 0.97 = 0.85 = 0.67 = Scoed on a 10 cm analogue scale. b Wilcoxon signed ank test fo paied samples. c Stict citeia. of abstinence was the same fo both occasions. Mean spem concentation, mean total numbe of spem pe ejaculate, mean pogessive motility, and mean mophology wee not statistically diffeent in the two semen samples. Discussion The significance of this study is 2-fold. Fist, it is appaent that, in ou patient and dono goups, sexual aousal duing mastubation did not have a significant effect on the quality of semen. Even an extenal sexual stimulus that significantly inceased the subjective sexual aousal in the subjects failed to induce any statistically significant changes in the quality of the ejaculate. Second, poviding patients with an eotic video duing mastubation made them feel moe at ease, inceased thei sexual aousal, and, while the quality of the ejaculate was not affected, it impoved the ease with which the sample was poduced. It has been epoted that the quality of an ejaculate poduced duing coitus is supeio to that poduced by mastubation with espect to semen volume, spem concentation, pogessive motility, and even mophology (Zavos, 1985; Zavos and Goodpastue, 1989; Sofikitis and Miyagawa, 1993). This diffeence is especially maked in men with oligozoospemia whee, duing coitus, the volume is inceased by 30 48%, the 150 Downloaded fom on 11 Febuay 2018 total spematozoa pe ejaculate by %, pogessive motility by 12-65%, and nomal mophology by 16-22% when compaed to samples obtained though mastubation (Zavos, 1985; Zavos and Goodpastue, 1989; Sofikitis and Miyagawa, 1993). In nomozoospemic individuals semen volume is inceased by 19-25%, total spematozoa pe ejaculate by 49-56%, pogessive motility by 8-10%, and nomal mophology by 4-5% (Zavos, 1985; Zavos and Goodpastue, 1989). It is not known what causes the significant diffeences in semen chaacteistics of ejaculates collected duing coitus vesus those obtained by mastubation. One could speculate that the highe degee of sexual aousal duing coitus might be a good candidate. It has been epoted, howeve, that coitus inteuptus, which povides optimal psychological and physical pe-ejaculatoy stimulation, esults in significantly lowe semen quality compaed to that poduced duing complete coitus (Zavos et al., 1994). In this light, it has been postulated that sufficient stimulation towads the end of the ejaculatoy pocess is equied fo optimal esults (Zavos et al., 1994). Howeve, the manne in which this stimulation should influence the volume and quality of ejaculate emains unclea. In the pesent study we found no evidence fo a modulatoy ole of sexual aousal in the quantity and quality of the ejaculates. In ode to contol fo laboatoy eos, all samples

5 Sexual aousal and semen quality wee evaluated by two well tained technicians using a single Makle counting chambe fo all specimens. Unde these conditions it should have been possible to distinguish a putative ole fo sexual aousal in the inta-subject vaiability of semen chaacteistics. In potential donos, no coelation was found between changes in subjective scoes with changes in semen paametes, while in goup A significant coelations wee found between A-intensity of ogasm and A-semen volume and, to a lesse extent between A-sexual aousal and A-semen volume. These coelations wee not appaent in goup B (esults not shown), and ae pobably not of clinical significance. This is similaly the case fo the negative coelation between A-satisfaction and A-motility in goup A. Exposing patients to an eotic video pio to and duing mastubation did not impove the quality of the ejaculate. With VES, howeve, significantly highe scoes wee given fo many of the subjective paametes. This was not only tue fo sexual aousal, intensity of ogasm, quality of eection, and satisfaction, but patients also epoted being moe at ease/ elaxed with the eotic video. In addition, thee was a maked incease in the epoted ease with which the ejaculate was poduced. Thus, the use of a sexually stimulating video will help to decease the appehension that many patients expeience when they 'have to' poduce a semen sample, and it facilitates poduction of the ejaculate fo analysis o, possibly, fo atificial epoductive techniques. The question aises as to what is esponsible fo the maked incease of the quality of an ejaculate poduced duing coitus compaed to a sample poduced duing mastubation, if it is not the highe level of sexual aousal. Since it has been shown that emission is unde consideable ceebal contol (Coma, 1970; Newman et al., 1982; Kuh et al, 1995), one could speculate that co-odinated ceebal activity duing the emission and ejaculation phase has an inhibitoy effect on the quality of the semen poduced. This would explain the infeioity of semen samples obtained by coitus inteuptus and mastubation vesus those poduced duing complete intecouse in a numbe of studies (Zavos, 1985; Zavos and Goodpastue, 1989; Sofikitis and Miyagawa, 1993; Zavos et al., 1994) as the fist two pocedues involve the co-odinated deposition of the semen sample in a hand-held containe. In addition, uvis et al. (1986) epoted no diffeence in semen chaacteistics between samples obtained by mastubation and coitus, when the sample obtained by mastubation was collected in a condom. In conclusion, we have found no evidence to suggest that the vaiability of an individual's semen chaacteistics, poduced by mastubation, is in any way alteed by the level of sexual aousal. It emains an enigma how an individual's inte-ejaculate dispaity can be explained. A positive outcome of the pesent study is the significance of visual eotic stimulation and a sexually moe positive atmosphee as facilitative factos in the poduction of a semen sample at a fetility clinic. Theefoe, the use of visual eotic stimulation fo patients, and pehaps donos, when they have to poduce a semen sample in the clinic is highly ecommended. Acknowledgements We gatefully acknowledge Maijke KJuit fo the expet technical wok, and Chis van Apeldoon fo excellent secetaial assistance. Downloaded fom on 11 Febuay 2018 Refeences Bake, H.W.G., Buge, H.G., de Ketse, D.M., Loding, D.W., McGowan,. and Rennie, G.C. (1981) Factos affecting the vaiability of semen analysis esults in infetile men. Int. J. 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