Screening therapeutic insemination donors for sexually transmitted diseases: overview and recommendations

Screening for sexually transmitted infection pathogens in semen samples

The transmission of sexually transmitted infection (STI) pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term reproductive complications or adverse outcomes of pregnancy, including infection of the offspring. Screening for bacterial STI pathogens, Chlamydia trachomatis and Neisseria gonorrhoeae is strongly recommended because these pathogens can cause serious reproductive complications in the recipients of semen donations and infection in their offspring. Screening for these pathogens should be performed using the most sensitive methods, such as nucleic acid amplified tests. False-negative results due to inhibitory substances in the semen sample should be monitored using amplification controls. Where specimen transport is not a problem and culture facilities are available, N gonorrhoeae can also be detected by culture. Laboratories performing screening should subscribe to proficiency programs and have strict quality controls. Although Trichomonas vaginalis, group B streptococcus and genital mycoplasmas have been associated with adverse outcomes of pregnancy, the frequent finding of these organisms in healthy individuals brings into question the validity of mandatory inclusion of these organisms in the screening panel. Although viral STI pathogens and Treponema pallidum - the causative agent of syphilis - may be detected in semen, their presence may be more sensitively detected through antibody testing of the donor. Screening donors for HIV, hepatitis B and syphilis by serology is uniformly recommended in all of the guidelines, but the value of screening either donors or semen samples for cytomegalovirus, herpes simplex viruses and human papilloma viruses is less clear.

Frequency of postinsemination infections as reported by donor semen recipients

Over an 18-year period, 47 women claimed to have acquired an infection after insemination with donor semen. This translates to an infection rate of less than 1 per 10,000 inseminations.

Semen donors and STD screening

AIM

The British Andrology Society recommends screening semen donors for sexually transmitted infections to minimise the risk of pathogen transmission to the mother and fetus. The aim was to review recent findings of semen donor screening and, if appropriate, recommend changes to the screening protocol.

SUBJECTS

175 consecutive men attending for STD screening between January 1992 and December 1995 who had been preselected by the Department of Obstetrics and Gynaecology as suitable semen donors.

METHODS

Retrospective review of case notes and group comparison of demographic and sexual history data.

RESULTS

11 men (6%) had evidence of infection, excluding CMV seropositivity, at their first STD screen. After semen donation, 109 men (63%) were rescreened and, of these, 12% had positive findings. Positive findings at initial screening were predicted by a history of more than one partner in the preceding 6 months (OR 7.11, 95% CI 1.66-30.4) but it did not predict rescreening findings. Other factors such as age, marital status, employment status or past STDs were not predictive for either screen.

DISCUSSION

Less than 20% of initial volunteers meet the full criteria of high quality post-thaw semen, no transmissible genetic disorders, and no transmissible pathogens. Sexual history may predict but would not alone preclude all positive STD screening findings. It is essential that sequential STD screening of donors continues and that genitourinary physicians should be involved in this process. Validation of newer diagnostic techniques as screening tests in this setting is required.

The biologic significance of white blood cells in semen

OBJECTIVE

To analyze the data available on the biologic significance of white blood cells (WBC) in semen of infertility patients.

DATA RESOURCES

The relevant literature was reviewed.

RESULTS

It is not possible to identify reliably WBC by conventional sperm staining techniques. The peroxidase method is sufficient for quantification of granulocytes, but immunocytology is the gold standard for the detection of all WBC populations in semen. Granulocytes are the most prevalent WBC type in semen (50% to 60%), followed by macrophages (20% to 30%) and T-lymphocytes (2% to 5%). The prevalence of leukocytospermia (> 10(6) WBC/mL semen) among male infertility patients is approximately 10% to 20%. There is controversy on the significance of WBC in semen. Whereas some authors did not observe sperm damage in the presence of leukocytospermia, others have found evidence that WBC are significant cofactors of male infertility: [1] seminal WBC numbers were higher in infertility patients than among fertile men; [2] leukocytospermia was associated with decreased sperm numbers and impaired sperm motility; [3] WBC damaged sperm function and hamster ovum penetration in vitro and were important prognostic factors for IVF-ET failure. Because of absence of clinical symptoms, the origin of WBC is difficult to determine. Normally, most WBC appear to originate from the epididymis because vasectomized men show very few WBC in semen. On the other hand, leukocytospermic samples show low citric acid levels, pointing to asymptomatic prostatitis as a source of WBC in semen. Surprisingly, approximately 80% of leukocytospermic samples are microbiologically negative. In some cases Chlamydia trachomatis might have triggered a persistent inflammatory reaction leading to leukocytospermia. Sperm damage by WBC can be mediated by reactive oxygen species, proteases and cytokines. Furthermore, genital tract inflammation facilitates the formation of sperm antibodies. As seminal plasma has strong anti-inflammatory properties and because there is only short contact between sperm and WBC in prostatitis and seminal vesiculitis, inflammations of the epididymis and testis are likely to have the largest impact on sperm.

CONCLUSIONS

There is ample evidence that WBC can affect sperm function. Further studies are needed to define cofactors that increase or decrease the risk of sperm damage by WBC.

Detection of Chlamydia trachomatis in semen of artificial insemination donors by the polymerase chain reaction

OBJECTIVE

To assess the feasibility of detecting Chlamydia trachomatis in cryopreserved donor semen by a specific, direct polymerase chain reaction (PCR).

DESIGN

Cryopreserved donor semen was tested for the presence of C. trachomatis by a specific PCR, directly applied to semen without prior DNA purification.

SETTING

Tertiary care fertility center in a teaching hospital and university-based laboratory for molecular pathology.

PARTICIPANTS

Cryopreserved semen from 30 donors was investigated. These semen samples had previously given negative results in cell culture for C. trachomatis. Two different ejaculates of each donor, cryopreserved with an interval of 2 years, were retrospectively analyzed.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

The presence of C. trachomatis as demonstrated by PCR.

RESULTS

In 3 of 30 donors C. trachomatis was detected in both ejaculates, whereas in 2 additional donors only one of the two samples tested positive. Additional samples from 2 positive donors, together with samples from 3 negative donors, were studied more extensively, to test the reproducibility and reliability of PCR results. All ejaculates of the donors, previously positive for C. trachomatis by PCR, indeed appeared to be positive, whereas the samples of the negative donors remained negative.

CONCLUSIONS

The direct PCR is a reliable, sensitive, and valuable method for detection of C. trachomatis in semen. The incidence of contamination of donor semen with C. trachomatis in the donor population in this study stresses the need for rigorous screening of donor semen before artificial insemination, preferably using a sensitive method such as the PCR.

Therapeutic donor insemination: a prospective randomized trial of fresh versus frozen sperm

OBJECTIVE

We evaluated the efficacy of fresh versus frozen sperm in therapeutic donor insemination.

STUDY DESIGN

Fifty-seven women underwent 72 courses of treatment (a maximum of six therapeutic donor insemination cycles--three fresh and three frozen) totaling 198 cycles. Each woman served as her own control and was prospectively randomized to receive a single, timed insemination of either fresh or frozen sperm.

RESULTS

Fecundity was 20.6% for fresh sperm cycles and 9.4% for frozen (p less than 0.03, by chi 2 analysis). Fresh cervical cap insemination fecundity was 20.3%; frozen was 7.8% (p less than 0.03, by chi 2 analysis). Fresh intrauterine insemination fecundity was 21.2%; frozen was 15.8% (p = 0.63, by chi 2 analysis). Fresh 3-month life-table pregnancy rates were 48% +/- 10%; frozen rates were 22% +/- 8% (p = 0.05 by Breslow analysis). Survival analysis with fixed covariates showed a positive association with the use of fresh sperm (p = 0.04).

CONCLUSION

Cycle fecundity was significantly greater with fresh sperm in women undergoing cervical cap insemination or intrauterine insemination and in women undergoing only cervical cap insemination. These results have important implications for contemporary management of patients undergoing therapeutic donor insemination with frozen sperm.

Donor insemination--a look to the future

In this article we have reviewed many aspects of donor insemination. The deficiencies in the screening of semen donors especially for sexually-transmitted diseases has been discussed and importance of a rational protocol for recruitment and screening of potential donors has been emphasized. Factors influencing the success and outcome of donor insemination have been reviewed with particular emphasis on providing prognostic guidelines to potential donor insemination couples as to the success and outcome of the treatment. The importance of accurate timing of inseminations in determining the success of donor insemination has also been discussed. However, as has been highlighted throughout this review, there is a lack of specific prospective controlled trials, which are clearly necessary to answer specific important questions. Also emphasized has been the need of these trials to answer such basic questions as the influence of accurate timing on conception rates in specific groups of insemination recipients.

Cryopreservation of human semen

A review is given of the techniques for the cryopreservation of human semen, including the preparation of cryoprotective media, the use of ampoules, straws, and pellets, and freezing and thawing techniques. The use of cryopreserved semen for therapeutic artificial insemination by donor is described. The advantages of cryopreserved semen over fresh donor semen mostly lie in the ability to exclude infections before use and the extra convenience, in spite of the lower success rate and increased cost. The recovery of sperm motility on thawing is described, as are other methods for assessing the degree of damage to the spermatozoa by the freezing procedure. The success rates reported by large semen banks are summarized.

Semen analysis data from fresh and cryopreserved donor ejaculates: comparison of cryoprotectants and pregnancy rates

Patients (155) were selected at random for fresh or cryopreserved semen and inseminated on the predicted day of ovulation. Semen analysis was performed using a microcomputerized multiple-exposure photography system. Frozen semen was used with either glycerol or TEST-yolk (TEST-buffered 20% egg yolk with 10% glycerol) as the cryoprotectant. Cryopreservation resulted in significant decreases in all semen parameters measured. Of these, velocity appeared to be the least effected. TEST-yolk provided significantly more protection against a reduction in velocity compared with glycerol. A total of 18, 17, and 27 patients conceived using fresh, glycerol, or TEST-yolk-preserved semen, respectively. For these same groups, a cumulative pregnancy rate of 52.9%, 27.1%, and 68.5%, respectively, was observed (not significant). The total number of motile sperm per insemination used for fresh artificial inseminations resulting in conception (132.4 X 10(6] was significantly greater than the number used for successful glycerol- and TEST-yolk-preserved semen (approximately 24 X 10(6]. These results demonstrate that although the number of motile sperm of cryopreserved ejaculates are dramatically reduced compared with the fresh counterparts, if a minimum criteria for ejaculate quality is established, the use of cryopreserved semen can offer a viable, effective, and relatively safe alternative to artificial insemination by donor with fresh semen.

Screening donors for sexually transmitted disease in donor insemination clinics in the UK. A survey

A survey conducted amongst the 40 donor insemination centres in the UK registered by the Royal College of Obstetricians and Gynaecologists (RCOG) showed that most of the clinics had no structured policy for control of common (non-HIV) sexually transmitted diseases within their programmes.

Transmission of sexually transmitted diseases by donor semen

Therapeutic insemination by donor (TID) is being used with increasing frequency. Because many diseases, some of which are lethal, can be transmitted through semen, the American Fertility Society established guidelines for use of donor sperm. They limit TID to cases of male infertility or hereditary/genetic disorders. Donor selection requires good health and absence of genetic abnormalities; criteria for semen including normal sperm motility, concentration, and normal morphology, and blood screening for infectious agents. Human immunodeficiency virus (HIV) testing should be performed initially in donors for fresh semen inseminations. If positive, the assay is verified with a Western blot test; if negative, the donor should be screened at 6-month intervals. Frozen samples should not be used until the 180 day reevaluation of the donor. Many studies show higher pregnancy rates using fresh rather than frozen semen samples for insemination. New methods of cryopreservation minimize the deleterious effects of freezing. If these effects, namely decreased sperm motility and impaired penetration ability, are eliminated, pregnancy rates can be expected to rise. Frozen semen is preferable because it allows time for sexually transmitted diseases to manifest themselves and for specimens from those donors to be rejected prior to use.

Results of artificial insemination at home by the partner with cryopreserved donor semen: a randomized study

The use of cryopreserved semen offers the possibility of home insemination by the instructed partner. A comparative study was designed whereby participants were randomly allocated to use home or clinic insemination for six cycles. If no pregnancy had occurred after six cycles, the site of insemination was switched to the opposite location for a maximum of six further cycles. Fifty-three women with primary infertility fulfilling all entry criteria entered the study. In the first 6 cycles out of 29 home starters, 13 pregnancies were conceived, whereas in 24 clinic starters 11 pregnancies occurred, yielding no statistical difference in pregnancy rate. Of 138 couples who did not meet the criteria in the same period, 45 opted for home insemination, resulting in 20 home-inseminated pregnancies. Again, for comparable subgroups no statistical difference in pregnancy rate between home and clinic insemination was found.

Culture of cytomegalovirus from frozen-thawed semen

Twenty-four donors in a TID program were tested for previous exposure to CMV. Four (16.7%) donors were seropositive for CMV. One donor's semen was culture-positive for CMV following cryopreservation and storage at -196 degrees C for up to 9 months. Culture reports for blinded specimens from the same ejaculate were all in agreement. Days to viral detection following inoculation of test cells were similar for specimens from the same ejaculate. Seminal quality was not adversely affected during the period of viral shedding. This appears to be the first report of survival of this previously reported cold labile virus in frozen-thawed semen.

Sexual behavior and risk for pelvic inflammatory disease

Sexual behavior characteristics of 35 patients with pelvic inflammatory disease (PID) and 44 healthy controls was studied prospectively. Patients with PID had sex more often than did controls (P less than 0.001). The mean number of sexual partners or age at first intercourse did not differ significantly between cases and controls. PID patients more often had oral sex than controls (P less than 0.05). These results suggest that sexual behavior characteristics may be important risk factors for PID, and should be prospectively studied in larger populations.