Fetal forearm anomalies: prenatal diagnosis, associations and management strategy.

OBJECTIVE

To determine the underlying associations in fetuses with forearm anomalies, and to derive a management strategy to improve prenatal diagnosis and parental counselling.

METHODS

A retrospective review of fetal medicine unit records to identify all cases with an absent, short or abnormal radius and/or ulna. Cases with a generalised skeletal dysplasia were excluded. Fetal medicine, maternal, neonatal and, where appropriate, histopathological reports, were reviewed.

RESULTS

Sixty-six cases were identified. Two were lost to follow-up and subsequently omitted. Chromosomal anomalies accounted for 19 cases (29.7%), genetic syndromes for 19 (29.7%) and isolated forearm defects for 15 cases (23%). A definitive postnatal diagnosis was made in 54 cases (84%). In 45 of the 64 (70%) cases, a correct prenatal diagnosis was made. Cases with bilateral lesions had a significantly higher association with aneuploidy and genetic syndromes, while those with a sonographically isolated unilateral forearm defect had a very low incidence of other underlying pathology.

CONCLUSION

Fetuses with bilateral forearm defects or those with unilateral lesions and other abnormalities detected prenatally have a high incidence of aneuploidy and genetic syndromes. Isolated, unilateral lesions usually have a good prognosis. A management strategy is presented to aid accurate prenatal diagnosis and parental counselling.