A review of prenatally detected femoral abnormalities

Abstract

Antenatally detected femoral abnormalities are a rare finding, and form a heterogeneous group in terms of diagnosis and prognosis. The objective of this study is to evaluate the management and outcome of fetuses after prenatal detection of femoral abnormalities in a tertiary care Fetal Medicine Unit over a 5-year period, thus facilitating accurate diagnosis and appropriate counseling. Patients were identified through a Regional Fetal Anomaly Database or clinician recall. Information was collected on whether the abnormality was an isolated or generalized skeletal abnormality, whether nonskeletal abnormalities were detected, what prognosis was counselled, whether referral to clinical genetics occurred, what investigations were performed, what was the eventual outcome and whether a final diagnosis was reached. A definitive diagnosis was made in 68% (28 of 41) of cases. However, a correct diagnosis was only achieved in 19% (eight of 41) of cases before delivery. Prognosis was correctly predicted in 83% (34 of 41) of cases. Families found the degree of uncertainty difficult, with 67% (six of nine) of patients where the prognosis was 'uncertain' electing to terminate the pregnancy. Eighty percent (eight of 10) of those where the condition was deemed 'lethal' also elected to end the pregnancy. In conclusion, it is difficult to achieve a correct diagnosis before delivery when a femoral abnormality is identified; however, detailed antenatal assessment may aid the differential diagnosis and help to determine prognosis. This was more likely to be achieved if the patient was seen in association with a clinical geneticist. A multidisciplinary team approach involving fetal medicine, genetics, paediatric radiology, and pathology is advocated. Fetal examination, medical photography, chromosomes and DNA storage, postnatal radiography and postmortem facilitate postnatal diagnosis and counseling.