Adult male circumcision was not associated with sexual dysfunction in this study. We found no significant difference between circumcised and uncircumcised men with respect to the frequency of erectile dysfunction, inability to ejaculate, pain during intercourse, lack of pleasure with inter-course, or these dysfunctions combined. On careful clinical evaluation over 2 years of follow-up, the circumcised men did not have evidence of penile deformities or long-term surgical complications. More than 99% were “satisfied” with their circumcisions. Only six men reported they were “dissatisfied” at the 6-month follow-up; each of these men reported being satisfied at either the 12-month or the 18-month visit, with no further dissatisfaction. Our findings support and substantially extend findings from another randomized trial of adult male circumcision that also found no significant difference in sexual function between circumcised men and uncircumcised controls [36
]. These critical findings are reassuring in view of current efforts to promote male circumcision to prevent HIV infections in some countries, particularly in eastern and southern Africa [40
]. We hope that these data can be used to inform public health recommendations for male circumcisions in other settings. In contrast to many other HIV prevention measures evaluated in clinical trials, male circumcision has proven to be effective, with approximately 60% reduction in HIV incidence among circumcised men.
Overall, 24.7% of the healthy 18- to 24-year-old men in our study reported at least one sexual dysfunction at baseline. Few studies have examined sexual dysfunction in young men. The items we used to assess sexual dysfunction are similar to the United States (NHSLS) [41
], British National Survey of Sexual Attitudes and Lifestyles (NATSAL) [42
], and Global Study of Sexual Attitudes and Behaviors [43
]. Among 18- to 29-year-olds in the NHSLS [41
], inability to reach orgasm was 7% (vs. 4.4% at baseline in our study), and erectile dysfunction was 7% (vs. 7% at baseline in our study). The NHSLS found a 30% prevalence of premature ejaculation in this age group [41
], almost double our 18% prevalence at baseline. The multinational Premature Ejaculation Prevalence and Attitudes survey also found an 18% prevalence of premature ejaculation among 18- to 24-year-olds [45
]. Although not age-stratified, excluding the question on lack of interest in sex, the NATSAL prevalence of any sexual dysfunction was 24% [43
], comparable with our 25% rate. In contrast to these reports, a randomized trial of male circumcision among men aged 15–49 in Uganda found that self-reported sexual dysfunctions were infrequent at enrollment, as assessed using four items: “difficulty to achieve and maintain an erection” reported by 1.3%, “difficulty with vaginal penetration” reported by 1.8%, “difficulty with ejaculation” reported by 0.6%, and “pain during or after intercourse” reported by 1.2% [36
]. Thus, the rate of sexual dysfunction in our study is generally comparable with the rates in young men surveyed in the United States [41
], Britain [42
], and most other countries [43
Besides documenting that circumcision had no significant adverse effect on male sexual function, our data suggest potential changes in sexual pleasure for some circumcised men. The circumcised men reported increased penile sensitivity and enhanced ease of reaching orgasm, subjective findings that may be considered to be either a potential benefit or an adverse effect by individual men. The circumcised men had progressively higher rates of sexual satisfaction over time, as well as a lower rate of balanitis. Reduced rates of reported sexual dysfunction in both the circumcised and control men over the course of the study may have a number of different interpretations, including regression to the mean, increased familiarity with the study questions, or another effect of repeated assessment. Alternatively, it may be that as these young men aged and became sexually more experienced, their sexual difficulties lessened, or they became better able to deal with them. Furthermore, they received regular counseling at frequent intervals from the study counselors. Counseling was mainly directed at HIV risk reduction, but general psychological counseling and support was provided, which may have had some impact in terms of handling sexual dysfunction, although no specific treatment for sexual dysfunction was provided. Most importantly, the reduction in sexual dysfunction was observed in both study arms. Having an uncircumcised control group allowed for the observation of such unanticipated factors, in contrast to other studies that were limited to evaluating adult men before and after circumcision [27
Over time, a large and increasing proportion of circumcised men reported having sex more frequently compared to before they were circumcised. This could be due to a perceived reduction in the risk of HIV acquisition (i.e., engaging in risk compensation). However, increased frequency of sexual activity may not necessarily reflect increased risk of HIV acquisition, if it is associated with having more sex with a regular partner or more sex with a condom. In any case, no difference was observed between the circumcised and uncircumcised men with regard to risky sexual practices (including unprotected sexual intercourse, recent sex with a casual sex partner, and inconsistent condom use), and there was a significant decrease in these behaviors in the circumcision group from before circumcision to after [2
]. Additionally, the circumcised men reported that condom use was easier after circumcision, and the proportion reporting this increased over time. Continued HIV/STI evaluation and counseling in HIV/STI risk reduction remain critical as male circumcision is introduced as an HIV prevention intervention.
This study has several limitations. We did not have direct observation of sexual function, partner reports, or physiologic or laboratory indicators of sexual dysfunction. While we assessed sexual dysfunction using questions similar to those used in other large population-based surveys [41
], we did not use validated instruments, such as the International Index of Erectile Function [46
] or a recently validated sexual quality of life questionnaire for use in men with premature ejaculation or erectile dysfunction [49
]. To translate and validate these instruments would have entailed substantial linguistic and cultural complexities. Although self-reported symptoms of sexual dysfunction differ from clinical diagnosis, self-report of erectile dysfunction correlates strongly (0.80) with urologic examination results [50
]. The prevalence of sexual dysfunction is subject to the definition and period of recall used [42
]. Lack of validated instruments may prove especially difficult in assessing items such as premature ejaculation, increased sensitivity, and the enhanced ease of reaching orgasm reported in our study; the latter might be another way of describing undesired premature ejaculation. However, premature ejaculation was not associated with increased penile sensitivity (P =
0.293) or with ease of reaching orgasm (P =
0.588). We did not have measures of diabetes, vascular disease, stress, and mental or emotional health. However, the young age of our population and the active lifestyle of participants in this trial, as well as medical screening for conditions contraindicating surgery, make it likely that few cases of sexual dysfunction resulted from chronic illnesses or medication use. Stability of the male–female relationship may influence the incidence of sexual dysfunction. Although 94.6% of participants in the circumcision group and 94.4% of participants in the control group were not married or living with a female partner, we did not have any other measure of relationship stability. We did not evaluate homosexual activities in our population, which might be influenced by circumcision status [51
]. Finally, men who were excluded from randomization because of medical indications for circumcision or genital abnormalities might have had higher rates of sexual dysfunction than the men enrolled in our trial.
Advantages of this study include the large number of men randomly assigned to circumcision evaluated against a control group prospectively; use of thorough medical histories and physical exams; use of global questions to assess multiple aspects of sexual function; and extensive data on sexual behavioral risks and STI diagnoses.
In summary, the circumcised men did not experience an increased risk of sexual dysfunction when compared with the uncircumcised control men. Among the circumcised men, penile sensitivity and ability to reach orgasm increased. The similar rates of sexual dysfunction between the circumcised and uncircumcised men suggest that integration of male circumcision into programs to reduce HIV transmission will not have adverse effects on male sexual function.