A review of a perinatal genetics and genomics service's role in prenatal diagnosis.

Abstract

Aims: The aim of this study was to review prenatal anomaly cases referred to the Department of Perinatal Genetics and Genomics at the National Maternity Hospital.

Methods: We conducted a retrospective review of all patients who were referred to the Department between August 2021 to April 2025. We included cases referred for consideration of further genetic testing because of a fetal anomaly where initial QF-PCR and chromosomal microarray studies did not reveal a genetic diagnosis.

Results: There were 109 patients who met our inclusion criteria. A molecular diagnosis was made in 56 (51.4%) of this cohort. These diagnoses were apparently de novo in 35 cases (62.5%) and inherited in 21 (37.5%). Pregnancy outcomes showed 31 cases (28.4 %) had a livebirth surviving the neonatal period.

Discussion: Our findings demonstrate the high diagnostic yield and clinical value of a dedicated Perinatal Genetics and Genomics service as part of the multi-disciplinary team for prenatal diagnosis. These cases all have a higher rate of recurrence in subsequent pregnancies compared to the empiric risk, indicating a need for ongoing genetics counselling in subsequent pregnancies. This data also indicates a high proportion of these patients experience a fetal or neonatal loss and that appropriate psychological input is needed.