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.