Expanded carrier screening: what the reproductive endocrinologist needs to know

Pregnancy Planning and Genetic Testing: Exploring Advantages, and Challenges

Pregnancy planning and genetic testing (PPGT) has emerged as a tool in reproductive healthcare, offering parents-to-be insight in their risks of having a child with a genetic disorder. This paper reviews the advantages, drawbacks and challenges associated with PPGT, providing some practical guidance for health care professionals. Advantages include identification of genetic risks, a possibility to informed reproductive decision-making, and the potential to reduce the parents-to-be risk for an affected child. Challenges and drawbacks include provision of service, ethical considerations, genetic counselling complexities, and the need to increase public and professional awareness by comprehensive education and accessibility. Practical guidance involves considerations for selecting appropriate candidates, counselling strategies, and how to integrate PPGT into existing healthcare frameworks. By addressing these factors, PPGT can offer an increased reproductive informed choice for the individual and the couple reducing the burden of disease in the family.

Perceptions of reproductive healthcare providers regarding their involvement in offering expanded carrier screening in fertility clinics: a qualitative study

RESEARCH QUESTION

What are the main arguments of reproductive healthcare providers in favour or against their involvement in offering expanded carrier screening (ECS) for recessive disorders at fertility clinics in the Netherlands?

DESIGN

Semi-structured interview study with 20 reproductive healthcare providers between May 2020 and January 2021. Participants included 11 gynaecologists, seven fertility doctors, one nurse practitioner and one clinical embryologist, recruited from academic medical centres (n = 13), peripheral facilities associated with academic centres (n = 4), and independent fertility treatment centres (n = 3) in the Netherlands. An interview guide was developed, and thematic content analysis was performed using ATLAS.ti software.

RESULTS

Arguments of reproductive healthcare providers in favour of their potential involvement in offering ECS included: (i) opportunities offered by the setting; (ii) motivation to assist in reproduction and prevent suffering; and (iii) to counter unwanted commercialization offers. Arguments against involvement included: (i) lack of knowledge and familiarity with offering ECS; (ii) insufficient staff and resources, and potential high costs for clinics and/or couples; (iii) the emotional impact it may have on couples; (iv) perceived complexity of counselling and expected elongation of waiting lists; and (v) expected low impact on reducing the burden of diseases. Participants felt that more evidence and research on the costs-benefits, implications and demand are needed prior to their involvement.

CONCLUSION

While agreeing that the field of medically assisted reproduction provides a unique opportunity to offer ECS, reproductive healthcare workers feel a lack of capability and limited motivation to offer ECS to all or a selection of couples at their fertility clinics.

Implementing preconception expanded carrier screening in a universal health care system: A model-based cost-effectiveness analysis

PURPOSE

The limited evidence available on the cost-effectiveness (CE) of expanded carrier screening (ECS) prevents its widespread use in most countries, including Italy. Herein, we aimed to estimate the CE of 3 ECS panels (ie, American College of Medical Genetics and Genomics [ACMG] Tier 1 screening, "Focused Screening," testing 15 severe, highly penetrant conditions, and ACMG Tier 3 screening) compared with no screening, the health care model currently adopted in Italy.

METHODS

The reference population consisted of Italian couples seeking pregnancy with no increased personal/familial genetic risk. The CE model was developed from the perspective of the Italian universal health care system and was based on the following assumptions: 100% sensitivity of investigated screening strategies, 77% intervention rate of at-risk couples (ARCs), and no risk to conceive an affected child by risk-averse couples opting for medical interventions.

RESULTS

The incremental CE ratios generated by comparing each genetic screening panel with no screening were: -14,875 ± 1,208 €/life years gained (LYG) for ACMG1S, -106,863 ± 2,379 €/LYG for Focused Screening, and -47,277 ± 1,430 €/LYG for ACMG3S. ACMG1S and Focused Screening were dominated by ACMG3S. The parameter uncertainty did not significantly affect the outcome of the analyses.

CONCLUSION

From a universal health care system perspective, all the 3 ECS panels considered in the study would be more cost-effective than no screening.

Connecting the dots: Carrier screening and the Genetic Information Nondiscrimination Act in the United States

OBJECTIVE

To highlight the possibility of genetic discrimination in the United States with respect to carrier screening under limitations of the Genetic Information Nondiscrimination Act (GINA) and to encourage providers to educate patients about this possibility during pretest counseling.

METHODS

Review of current professional guidelines and practice resources regarding the necessary components of pretest counseling for carrier screening in the context of GINA's limitations and the potential impact of carrier screening results on life, long-term care and disability insurance.

RESULTS

Current practice resources advise that patients in the United States should be informed that their employer or health insurance company generally cannot use their genetic information during the underwriting process. However, these resources do not elaborate on GINA's limitations or explain why there may be adverse consequences to patients regarding these limitations. Studies have demonstrated significant gaps in provider knowledge of GINA, especially for those without formal genetic training.

CONCLUSION

Enhanced education and provision of GINA educational resources for providers and patients will help ensure that patients have the opportunity to prioritize their insurance needs prior to undergoing carrier screening.

General infertility workup in times of high assisted reproductive technology efficacy

The assessments of oocyte quality and quantity and endocrine profile have traditionally been the cornerstone of the general workup of couples with infertility. Over the years, several clinical, hormonal, and functional biomarkers have been adopted to assess ovarian function and identify endocrine disorders before assisted reproductive technology. Furthermore, the genetic workup of patients has drastically changed, introducing novel markers. This not only allowed the prediction of response to ovarian stimulation but also contributed toward the development of a safer and more efficient management of women undergoing assisted reproductive technology. The scope of this review is to provide an overview of the current and novel strategies adopted for the assessment of ovarian function and ovulatory and endocrine disorders in women planning to conceive. Furthermore, it aims to provide an insight in the role of novel genetic biomarkers and use of expanded carrier screening as part of preliminary workup of women with infertility.

The use of expanded carrier screening of gamete donors

STUDY QUESTION

What are the sperm and egg donor rejection rates after expanded carrier screening (ECS)?

SUMMARY ANSWER

Using an ECS panel looking at 46/47 genes, 17.6% of donors were rejected.

WHAT IS KNOWN ALREADY

The use of ECS is becoming commonplace in assisted reproductive technology, including testing of egg and sperm donors. Most national guidelines recommend rejection of donors if they are carriers of a genetic disease. If the use of ECS increases, there will be a decline in the number of donors available.

STUDY DESIGN, SIZE, DURATION

A review of the current preconception ECS panels available to donors was carried out through an online search. The genetic testing results of donors from Cryos International were analysed to determine how many were rejected on the basis of the ECS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on gamete donors and their carrier status was provided by Cryos International, who screen donors using their own bespoke ECS panel. The ECS panels identified through the review were compared to the Cryos International panel and data.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 16 companies and 42 associated ECS panels were reviewed. There were a total of 2673 unique disorders covered by the panels examined, with a mean of 329 disorders screened. None of these disorders were common to all panels. Cryos International screen 46 disorders in males and 47 in females. From 883 candidate donors, 17.6% (155/883) were rejected based on their ECS result. Carriers of alpha-thalassaemia represented the largest proportion of those rejected (19.4%, 30/155), then spinal muscular atrophy (15.5%, 24/155) and cystic fibrosis (14.8%, 23/155).

LIMITATIONS, REASONS FOR CAUTION

Panel information was found on company websites and may not have been accurate.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the need for consistent EU regulations and guidelines that allow genetic matching of gamete donors to their recipients, preventing the need to reject donors who are known carriers. A larger ECS panel would be most beneficial; however, this would not be viable without matching of donors and recipients.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained. J.C.H. is the founder of Global Women Connected, a platform to discuss women's health issues and the Embryology and PGD Academy, who deliver education in clinical embryology. She has been paid to give a lecture by Cryos in 2019. A-B.S. is an employee of Cryos International.

TRIAL REGISTRATION NUMBER

N/A.

Expanded carrier screening should not be mandatory for gamete donors

More and more centers are imposing expanded carrier screening (ECS) on their gamete donors. In some clinics and gamete banks, gamete donors are not given this right, contrary to the freedom to decline genetic screening in the general population. The possible social and psychological burdens that are recognized for infertility patients and the general population are downplayed for gamete donors. The procedure of imposing ECS on gamete donors shows that the interests of the recipients are valued higher than those of the donors. The general ethical argument defended here is the principle of proportionality: the burdens imposed on donors have to be balanced against the potential benefits for the offspring and the recipients. The risk reduction of ECS is below 1% and is too small to outweigh the potential dangers and disadvantages for donors. The conclusion is that clinics may ask, but not compel, donors to submit to ECS provided that they offer appropriate genetic and psychological counseling.

Expanded carrier screening for recessively inherited disorders: economic burden and factors in decision-making when one individual in a couple is identified as a carrier

PURPOSE

When undergoing expanded carrier screening (ECS), couples are often screened sequentially to reduce need for a second individual's test. It is unknown how often partners of individuals found to be carriers complete the recommended testing with a sequential approach and what factors contribute to decision-making regarding partner testing. Additionally, the economic burden placed on individuals by ECS testing and its effect on partner testing has not been evaluated.

METHODS

In part 1, all individuals at a university-affiliated reproductive endocrinology and infertility practice identified to be carriers of a recessively inherited mutation using the Counsyl/Foresight ECS were included. Conditions were categorized by severity according to a previously described classification system. In part 2, all individuals who underwent ECS with a single test provider between September 1, 2013 and February 1, 2020 were contacted via email to complete a confidential and anonymized online survey.

RESULTS

In part 1, a total of 2061 patients were screened. 36.9% were carriers of one or more recessively inherited disorders. Twenty-seven percent of positively screened individuals did not have their partner screened. Carriers of a moderate condition had a trend towards a reduced odds for having their partner screened compared to a profound condition (OR 0.36, 95% CI 0.12-1.05, p = 0.06). Number of conditions was not predictive of subsequent partner screening (OR 0.95, 95% CI 0.72-1.25, p = 0.72). In part 2, the cost of ECS was not covered by insurance for 54.5% (103/189) and most paid over $300 out-of-pocket for testing (47.6%). The most common reason for not completing partner testing was that the results would not alter their course when seeking conception (33.3%). 73.5% of patients knew that the largest benefit of ECS comes from knowing a partner's results as well as their own.

CONCLUSIONS

Not all carriers of recessively inherited disorders choose to undergo partner screening. Patients found to be carrier of more debilitating genetic disorders may be more likely to screen their reproductive partners. For many, ECS testing is not covered by insurance, and this test may impose a significant economic burden. For some patients, the results of ECS would not change what they would do when seeking conception. Providers should evaluate whether a patient's ECS result would change their treatment course prior to testing.

A Transparent Approach to Calculate Detection Rate and Residual Risk for Carrier Screening

Carrier screening involves detection of carrier status for genes associated with recessive conditions. A negative carrier screening test result bears a nonzero residual risk (RR) for the individual to have an affected child. The RR depends on the prevalence of specific conditions and the detection rate (DR) of the test itself. Herein, we provide a detailed approach for calculating DR and RR. DR was calculated on the basis of the sum of disease allele frequencies (DAFs) of pathogenic variants found in published literature. As a proof of concept, DAF data for cystic fibrosis were compared with society guidelines. The DAF data calculated by this method were consistent with the published cystic fibrosis guideline. In addition, we compared DAF for four genes (ABCC8, ASPA, GAA, and MMUT) across three laboratories, and outlined the likely reasons for discrepancies between these laboratories. The utility of carrier screening is to support couples with information while making reproductive choices. Accurate development of DR and RR is therefore critical. The method described herein provides an unbiased and transparent process to collect, calculate, and report these data.

Expanded carrier screening for preconception reproductive risk assessment: Prevalence of carrier status in a Mexican population

OBJECTIVE

Genetic carrier screening has the potential to identify couples at risk of having a child affected with an autosomal recessive or X-linked disorder. However, the current prevalence of carrier status for these conditions in developing countries is not well defined. This study assesses the prevalence of carrier status of selected genetic conditions utilizing an expanded, pan-ethnic genetic carrier screening panel (ECS) in a large population of Mexican patients.

METHODS

Retrospective chart review of all patients tested with a single ECS panel at an international infertility center from 2012 to 2018 were included, and the prevalence of positive carrier status in a Mexican population was evaluated.

RESULTS

Eight hundred five individuals were analyzed with ECS testing for 283 genetic conditions. Three hundred fifty-two carriers (43.7%) were identified with 503 pathogenic variants in 145 different genes. Seventeen of the 391 participating couples (4.34%) were identified as being at-risk couples. The most prevalent alleles found were associated with alpha thalassemia, cystic fibrosis, GJB2 nonsyndromic hearing loss, biotinidase deficiency, and familial Mediterranean fever.

CONCLUSION

Based on the prevalence and severity of Mendelian disorders, we recommend that couples who wish to conceive regardless of their ethnicity background explore carrier screening and genetic counseling prior to reproductive medical treatment.

Expanded genetic carrier screening in clinical practice: a current survey of patient impressions and attitudes

PURPOSE

Expanded genetic carrier screening (ECS) is an important part of gynecological practice and preconception planning. We evaluated the awareness and attitudes among women regarding ECS and factors that may influence decision-making in a family planning context.

METHODS

A 32-question survey in an academic university practice was given to 521 women who were either currently pregnant (n = 108), undergoing gynecologic care who were considering future fertility (n = 308), and considering or receiving fertility treatment (n = 105). Data are reported descriptively.

RESULTS

Forty-seven percent (n = 246) of patients were aware of ECS. Though most reported feeling positive or neutral towards ECS, 51% (n = 263) reported no desire for testing. Fifty-eight percent (n = 303) felt it beneficial to know their carrier status, and 55% (n = 257) said it was their responsibility to undergo testing. Those considering future fertility were found to have a more positive attitude towards ECS (51.4%) than those considering or receiving fertility treatment (34%). For positive carriers of a genetic disorder, 228 (49%) of patients would proceed with having their partner screened, 58 (13%) would undergo prenatal screening only and 12 (2.6%) would continue with vitro fertilization (IVF). Related to cost for ECS, 53.5% (n = 191) would be willing to pay at least $50-100 for testing, while 29% (n = 146) would not pay anything out of pocket.

CONCLUSIONS

Despite patients' beliefs that it would be beneficial and their responsibility to undergo carrier status testing, the majority reported no desire for ECS and many were unwilling to pay out of pocket. Further education is necessary to reconcile the gap between technology and patient decision-making.