Genetic evaluation procedures at sperm banks in the United States

The Impact of Obesity on Sperm Parameters in Young Adult Males: A Retrospective Study of Sperm Donors

OBJECTIVE

To utilize a large cohort of healthy sperm bank donors to evaluate the association between body mass index and individual sperm parameters.

METHODS

Sperm parameters from donors across the United States were obtained between 2013 and 2022. Donors were healthy men aged 18-46years old. Semen samples were analyzed in a certified lab following guidelines by the World Health Organization. A multivariable interaction model between age, body mass index, and sperm parameters was conducted.

RESULTS

There were 117,357 sperm donations included in our study. In our sample, 98,397 (83.84%) men were classified as young donors (ages 18-32years) and 18,960 (16.16%) were classified as old donors (ages 33-46years). We identified 1032 (0.88%) men as underweight, 76,635 (65.30%) as normal weight, 36,686 (31.26%) as overweight, and 3004 (2.56%) as obese. Participants had a median total motile sperm count (TMSC) of 186 (interquartile ranges [IQR]: 128 million), volume of 3.36 (IQR: 1.82 mL), sperm concentration of 56 (IQR: 34 million/mL) and a progressive motility of 59.84% (IQR: 16.95%). Older obese donor had lower TMSC (β = -22.98 ± 4.66, P < .001), semen volumes (β = -0.85 ± 0.06, P < .001), and progressive motility (β = -3.94 ± 0.56, P < .001) compared to younger, healthy weight donors.

CONCLUSION

We observed lower TMSC, semen volumes, and progressive motility in older obese donors. Although these values are within the normal expected ranges for individual sperm parameters, our ability to detect differences within this healthy population highlights the importance of maintaining a healthy diet and exercise regimen for preserving high sperm counts.

Incidence of and indications for sperm donor restriction - analysis of patients continuing treatment: a retrospective single-centre study

RESEARCH QUESTION

What are the incidence of and indications for sperm donor restriction due to suspected/confirmed disease risk, and the future treatment choices of patients using these sperm donors?

DESIGN

This single-centre retrospective study involved donors who had restrictions on the use of their imported spermatozoa from January 2010 to December 2019, and current or previous recipients. Indications for sperm restriction and the characteristics of patients undergoing medically assisted reproduction (MAR) treatment with these specimens at the time of restriction were collected. Differential characteristics of women who decided on whether or not to contintue the procedure were assessed. Characteristics potentially leading to treatment continuation were identified.

RESULTS

Of 1124 sperm donors identified, 200 (17.8%) were restricted, most commonly for multifactorial (27.5%) and autosomal recessive (17.5%) disorders. The spermatozoa had been used for 798 recipients, of whom 172, receiving spermatozoa from 100 donors, were informed about the restriction and constituted the 'decision cohort'. The specimens from the restricted donors were accepted by 71 (approximately 40%) patients, with 45 (approximately 63%) eventually using the restricted donor for their future MAR treatment. The odds of accepting the restricted spermatozoa decreased with increasing age (OR 0.857, 95% CI 0.800-0.918, P < 0.001) and the time between MAR treatment and the restriction date (OR 0.806, 95% CI 0.713-0.911, P < 0.001).

CONCLUSION

Donor restriction due to suspected/confirmed disease risk is relatively frequent. This affected a relevant number of women (around 800), of whom 172 (approximately 20%) had to decide whether or not to use these donors further. Although donor screening is being performed thoroughly, there remain health risks for donor children. Realistic counselling of all stakeholders involved is necessary.

Genetic testing of sperm donors in China: a survey of current practices

Background

The National Health and Family Planning Commission of China (NHFPCC) issued the "Measures for the Management of Human Sperm Banks," which was revised in 2003 and is still in effect today. One of the standard guidelines is that potential donors undergo laboratory testing to exclude infectious and genetic diseases and karyotype analysis. However, patient demands for donor genetic testing have also increased, and only karyotype analysis to exclude genetic diseases is not sufficient to meet these demands.

Objective

To examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks.

Materials and methods

An electronic survey was distributed to twenty-seven sperm banks to examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Twenty-six human sperm banks responded to a 32-question survey about their current practices related to genetic testing of sperm donors.

Results

The 26 sperm banks reported that all qualified sperm donors undergo karyotype analysis; 22 banks (84.6%) collected three generations of family history from each qualified sperm donor; 10 (38.5%) reported that they attempted to accommodate special requests from donor semen recipients for particular genetic tests. Only 2 of the 26 (7.7%) sperm banks reported that they performed whole-exome sequencing. At all the sperm banks, consent for genetic testing was obtained as part of the overall contract for sperm donors. Nineteen (73.1%) sperm banks had genetic counselors on their staff, while six (23.1%) had no genetic counselors on their staff but had access to genetic counselors at the hospital. Only one (3.8%) sperm bank had no genetic counselors on their staff or at the hospital.

Conclusions

The need for larger scale genetic testing of donors and recipients and an extensive panel of genetic tests specific to the Chinese population. Additionally, professionally trained geneticists must be employed as genetic counsellors so that the results of genetic tests and their implications can be explained to donors.

Pregnancy and offspring outcomes after artificial insemination with donor sperm: A retrospective analysis of 1805 treatment cycles performed in Northwest China

Artificial insemination with donor sperm (AID) is a widely used procedure, but its success rate in China remains uncharacterized. This study investigated the factors associated with occurrence of clinical pregnancy and live birth and evaluated the birth outcomes in the offspring after AID in Northwest China.We retrospectively reviewed the results of 1805 AID courses in 1046 couples during 2006-2015. We analyzed whether the number of AID cycles, age of the female patient, and number of sperm with progressive motility were associated with the occurrence of clinical pregnancy and live birth. We also evaluated the birth outcomes in the offspring.Among the 1805 cycles, 447 (24.8%) resulted in clinical pregnancy and 384 (21.3%) resulted in a live birth. Miscarriage occurred in 57 of the 447 cases of clinical pregnancy (12.8%). The proportion of cycles resulting in a live birth decreased significantly with age (P < .001). The proportion of clinical pregnancies that resulted in miscarriage increased with age (P < .001). Cumulative pregnancy rate (the proportion of patients achieving a clinical pregnancy) increased progressively from 23.0% after 1 cycle to 42.7% after ≥5 cycles. The proportion of cycles resulting in clinical pregnancy did not vary with the total number of sperm with progressive motility administered per cycle. Multivariate logistic regression analysis revealed that superovulation treatment and number of cycles were factors associated with clinical pregnancy, while superovulation treatment, number of cycles, and patient age were factors associated with live birth. Among the 384 live births, only one case (0.3%) of birth defect (hexadactyly) was observed.In patients undergoing AID, clinical pregnancy is associated with superovulation treatment and number of cycles, and live birth is associated with superovulation treatment, number of cycles, and patient age. The risk of birth defects in the offspring after AID is low.

Carrier Screening is a Deficient Strategy for Determining Sperm Donor Eligibility and Reducing Risk of Disease in Recipient Children

Aims: DNA-based carrier screening is a standard component of donor eligibility protocols practiced by U.S. sperm banks. Applicants who test positive for carrying a recessive disease mutation are typically disqualified. The aim of our study was to examine the utility of a range of screening panels adopted by the industry and the effectiveness of the screening paradigm in reducing a future child's risk of inheriting disease. Methods: A cohort of 27 donor applicants, who tested negative on an initial cystic fibrosis carrier test, was further screened with three expanded commercial carrier testing panels. These results were then compared to a systematic analysis of the applicants' DNA using next-generation sequencing (NGS) data. Results: The carrier panels detected serious pediatric disease mutations in one, four, or six donor applicants. Because each panel screens distinct regions of the genome, no single donor was uniformly identified as carrier positive by all three panels. In contrast, systematic NGS analysis identified all donors as carriers of one or more mutations associated with severe monogenic pediatric disease. These included 30 variants classified as “pathogenic” based on clinical observation and 66 with a high likelihood of causing gene dysfunction. Conclusion: Despite tremendous advances in variant identification, understanding, and analysis, the vast majority of disease-causing mutation combinations remain undetected by commercial carrier screening panels, which cover a narrow, and often distinct, subset of genes and mutations. The biological reality is that all donors and recipients carry serious recessive disease mutations. This challenges the utility of any screening protocol that anchors donor eligibility to carrier status. A more effective approach to reducing recessive disease risk would consider joint comprehensive analysis of both donor and recipient disease mutations. This type of high-resolution recessive disease risk analysis is now available and affordable, but industry practice must be modified to incorporate its use.