709 - National Multi-Specialty Survey of Prenatal Genetic Testing Practices for Congenital Diaphragmatic Hernia within the Children’s Hospitals Neonatal Consortium

Publication Number: 1686.709

Zachary A. Whitt, Emory University School of Medicine, Atlanta, GA, United States; DonnaMaria E. Cortezzo, Connecticut Children's Medical Center, Hartford, CT, United States; K. Taylor Wild, Children’s Hospital of Philadelphia, Philadelphia, PA, United States; David McCulley, University of California, San Diego School of Medicine, San Diego, CA, United States; Sarah Keene, Emory/Childrens Healthcare Of Atlanta, Decatur, GA, United States; Syed T. Ahmed, University of Texas Southwestern Medical School, Dallas, TX, United States; Sandy Johng, Seattle Children's, Seattle, WA, United States; Michelle J. Yang, University of Utah School of Medicine, Salt Lake City, UT, United States; Katrin Lichtsinn, Seattle Children's, Seattle, WA, United States; Mihai Puia-Dumitrescu, University of Washington School of Medicine, Seattle, WA, United States; Kelsey A. Montgomery, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, United States; Sharada Gowda, Riley Children’s Hospital, Indianapolis, IN, United States

Background: Congenital diaphragmatic hernia (CDH) is diagnosed prenatally in up to 70% of cases. Current literature suggests that 20-32% of individuals with CDH have an identifiable genetic diagnosis. With the rise of fetal treatment for CDH and increased access to genetic testing, more parents seek prenatal evaluation, including genetic testing. However, there is still significant variation in testing without consensus.

Objective: Determine the current practices regarding prenatal genetic testing for fetuses with CDH through a national, multidisciplinary survey of prenatal care providers within the Children's Hospitals Neonatal Consortium (CHNC).

Design/Methods: A REDCap survey underwent pretesting and pilot testing from multicenter experts in the field. The survey was distributed to CHNC site sponsors for dissemination to prenatal care providers from April to July 2025. Data were analyzed using Fisher's Exact or Chi-squared tests.

Results: 77 responses from 22 centers addressed prenatal care. Most respondents were neonatologists (40%), with additional input from maternal-fetal medicine (MFM) specialists, pediatric surgeons, geneticists, genetic counselors, and other subspecialists. Seventy-two percent of respondents reported offering a chromosomal microarray (CMA) for any fetus with CDH, while 43% reported altering their approach to testing for fetuses with complex CDH. The use of karyotype (p < 0.009) and CMA (p=0.016) decreased for complex CDH compared to all CDH. There was a nonsignificant increase in sequencing modalities. Identification of a genetic condition influenced medical decision-making "always" (31%) or "sometimes" (54%) affected genetic counseling, consideration of pregnancy continuation, ECMO candidacy, and delivery planning. Among sites offering fetal treatment, 83% required genetic testing, most commonly a karyotype (80%). Reported barriers included parental preference, insurance limitations, and lack of standardized testing guidelines.

Conclusion(s): This multi-institutional, multidisciplinary survey demonstrates that most providers offer prenatal genetic testing for fetuses with CDH; however, substantial variation exists in testing approaches across centers. Given the potential impact of identifying a genetic condition in individuals with CDH, the increasing interest, and access to fetal treatment, this study highlights the need for consensus guidelines and standardized practices. Standardization of prenatal genetic testing will improve our understanding of CDH pathogenesis, decrease barriers to fetal testing, and enhance the efficacy of novel fetal therapies.

Figure 1: Prenatal Respondent Specialty
In this figure, this demonstrates the total number of respondents as well as their self-reported specialties which demonstrates a large and diverse response.

Figure 2: Genetic Testing Modality For All CDH Compared to Complex CDH
In this figure, all types of CDH most frequently had a Chromosomal Microarray (CMA) ordered. However, when compared to the patients prenatally determined to have a complex CDH the percent of respondents who would order a Karyotype or CMA had a statistically significant decrease, while the sequencing modalities (gene panel, exome, or genome) had an increase, it was not statistically significant.

Figure 3: Prenatal Changes in Medical Decision Making
In this figure, respondents who indicated that they would alter their medical decision making given that their patient had a diagnostic genetic test showed that there would be alterations in the counseling that they would have with the family, the child's ECMO candidacy, and delivery room management of the infant.