Non-invasive prenatal screening: Testing motivations and decision making in the low-risk population.

Non-invasive prenatal screening provides a risk assessment for aneuploidies by utilizing cell-free DNA (cfDNA). It is recommended that cell-free DNA screening (cfDNA screening) be offered to all pregnant people regardless of a priori risk for aneuploidy. In the absence of an increased risk, alternative motives for electing cfDNA screening and different levels of informed decision making may arise. Therefore, our study aimed to characterize low-risk patients' motivations for cfDNA screening election, determine how often informed decisions are being made, and compare motivations between informed and uninformed decision makers. A survey that included a modified, validated measure of informed choice (MMIC) and questions to assess patients' motivations for cfDNA screening was offered at four MFM clinics following genetic counseling. It was found that 44% of participants (n = 100) made an uninformed decision about testing. Participants with private insurers were 4.25 times more likely to make an informed decision (95% CI = 1.10-16.37). Informed decision makers scored avoiding invasive procedures higher (p = 0.007) and ranked doing what family/friends desire lower (p = 0.005) than uninformed decision makers. While most participants scored receiving information about genetic conditions highest, 12% of participants reported fetal sex disclosure as a priority. However, this was not found to be associated with uninformed decision making. This study ultimately established that following genetic counseling, a low-risk population shared motivations with high-risk populations which highlights the importance of complete pre-test counseling for all. Future research should investigate the effect of modifying variables, such as socioeconomic status, on the performance of informed choice measures and critically evaluate the parameters that determine informed choice.

Utility of expanded carrier screening in pregnancies with ultrasound abnormalities.

OBJECTIVE: Explore the utility of expanded carrier screening in evaluating heritable causes of congenital anomalies detected by prenatal ultrasound. METHOD: A retrospective chart review was conducted to collect structural abnormality and genetic testing data on infants who were evaluated postnatally by a medical geneticist. These were used to determine if expanded carrier screening could have determined the etiology prior to delivery. Additionally, recessive and X-linked conditions on clinically available carrier screening panels were evaluated to determine the number of conditions associated with abnormal ultrasound findings. RESULTS: Our retrospective chart review found 222 patients with genetic etiologies, including eight unique autosomal recessive conditions and six X-linked conditions in the 23% who underwent exome sequencing. Of these 14 unique conditions detected, three were included on a list of 271 conditions for which screening was available in 2019 and five were included on a 500 condition panel available in 2020. A literature review was performed on the list of 271 conditions and 88 were reported to be associated with one or more ultrasound abnormalities. CONCLUSION: This study demonstrates limited but potential utility for expanded carrier screening to determine the underlying etiology of congenital anomalies.

It takes two: uptake of carrier screening among male reproductive partners.

OBJECTIVE: To describe uptake of carrier screening by male reproductive partners of prenatal and preconception patients. METHODS: A retrospective database review of all prenatal and preconception patients seen for genetic counseling in Maternal Fetal Medicine clinics was performed. Descriptive statistics and chi-square analysis were used on the data set. RESULTS: Within the study period, 6087 patients were seen for genetic counseling, of whom 661 were identified as a carrier of an autosomal recessive disorder by their referring provider or genetic counselor. Despite guidelines recommending partner testing for risk clarification when a woman is known to be a carrier of an autosomal recessive condition, only 41.5% male partners elected carrier screening to clarify the couple's reproductive risk, with a majority of males (75%) having screening consecutively. Of all assessed variables, the only significant predictors of male carrier screening uptake were female parity and earlier gestational age (p < .0001, and p = .001, respectively). CONCLUSION: With less than half of male partners pursuing carrier screening when indicated, its utility becomes severely diminished. More research is needed to explore reasons why males elect or decline carrier screening.

Somatic mismatch repair testing in evaluation of Lynch syndrome: The gap between preferred and current practices.

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome primarily defined by increased risk for colorectal and uterine cancers. Individuals with germline pathogenic variants in the mismatch repair (MMR) genes (MLH1, MSH2/EPCAM, MSH6, and PMS2) are diagnosed with LS and recommended high-risk screening protocols to increase prevention and early detection of LS-related cancers. Tumor testing can help identify those at high risk for LS, but sometimes creates uncertainty with discordant screening and germline results, or unexplained mismatch repair deficiency (UMMRD). Somatic testing for MMR genes may help resolve UMMRD, potentially clarifying LS status and modifying cancer surveillance. However, guidelines for such testing are currently limited. This survey of cancer genetic counselors (GCs) aimed to examine current versus preferred ordering practices and interpretation of somatic MMR testing results in LS evaluation. Two hundred eligible GCs practicing in the United States and Canada were recruited from the National Society of Genetic Counselors. Participants answered questions regarding ordering practices, barriers to somatic MMR testing, theoretical scenarios, and desire for further guidelines. Statistical analysis was performed using chi-square, Fisher's exact, and Wilcoxon rank-sum tests, while themes were identified from free-text responses. Most respondents did not include somatic MMR testing in the LS work-up, despite three-quarters reporting they were 'somewhat comfortable' or 'extremely comfortable' with interpreting these results. Approximately half of participants indicated interest in ordering concurrent somatic MMR and germline testing for each of the four theoretical scenarios. Over three-quarters of individuals reported barriers to ordering somatic MMR testing, with cost and coordinating tissue samples most commonly cited. The frequently reported laboratory- and insurance-related barriers may contribute to the gap between preferred and current ordering practices for somatic MMR testing. Nearly all respondents endorsed additional guidelines for this testing, which could reduce barriers and inform screening recommendations for patients with UMMRD and their family members.

Prenatal chromosomal microarray uptake with invasive prenatal diagnosis: How many patients take the leap?

OBJECTIVE: Characterize the uptake of chromosomal microarray analysis (CMA) among women undergoing invasive prenatal diagnosis at a large academic institution over a 4-year time period. METHODS: Retrospective database review of women who underwent invasive prenatal diagnosis via chorionic villus sampling (CVS) or amniocentesis. Entries were reviewed for demographic and clinical information. RESULTS: Nine hundred forty-six diagnostic procedures were performed at our institution over a 4-year time period including 259 CVS and 687 amniocentesis procedures. Overall, 32% elected CMA, with a significant increase in uptake over time. Women with Medicaid/CHIP insurance were more likely to elect CMA than those with private insurance (OR = 1.59, 95% CI, 1.18-2.14), while multigravida women were less likely than primigravidas to elect CMA (P = 0.003). Women with ultrasound findings were more likely to elect CMA than any other indication. Those with structural abnormalities in multiple systems (OR = 3.75, 95% CI, 1.60-8.79) or abnormalities in a single system (OR = 3.22, 95% CI, 1.47-7.05) were more likely to elect CMA than with any other types of ultrasound findings. CONCLUSION: The uptake of CMA significantly increased over a 4-year period at a large academic institution. Women with ultrasound indications, specifically structural abnormalities, are the most likely to elect CMA.