Prenatal ultrasound finding of atypical genitalia: Counseling, genetic testing and outcomes

Objective To report uptake of genetic counseling (GC) and prenatal genetic testing after the finding of atypical genitalia on prenatal ultrasound (US) and the clinical and genetic findings of these pregnancies. Methods A retrospective cohort study (2017-2019) of atypical fetal genitalia in a large expert center for disorders/differences of sex development. We describe counseling aspects, invasive prenatal testing, genetic and clinical outcome of fetuses apparently without [group 1, n = 22 (38%)] or with [group 2, n = 36 (62%)] additional anomalies on US. Results In group 1, 86% of parents opted for GC versus 72% in group 2, and respectively 58% and 15% of these parents refrained from invasive testing. Atypical genitalia were postnatally confirmed in 91% (group 1) and 64% (group 2), indicating a high rate of false positive US diagnosis of ambiguous genitalia. Four genetic diagnoses were established in group 1 (18%) and 10 in group 2 (28%). The total genetic diagnostic yield was 24%. No terminations of pregnancy occurred in group 1. Conclusions For optimal care, referral for an expert fetal US scan, GC and invasive diagnostics including broad testing should be offered after prenatal detection of isolated atypical genitalia.