Volume 8 Issue 3 - Australasian Society for Ultrasound in Medicine

ASUM Ultrasound Bulletin 2005 August; 8 (3): 15–17DIAGNOSTIC ULTRASOUNDAbnormal fetal feet – the differentialdiagnosesD Fauchon A AMS, S Watson BHA, Grad Dip Ultrasound A , RJ Benzie MBChB, FRCS(c), FRANZCOG, ARDMS ABAChristopher Kohlenberg Department of Perinatal Ultrasound, Nepean Hospital, University of Sydney,Penrith, New South Wales, AustraliaBCorrespondence to David Fauchon email FauchoD@wahs.nsw.gov.auFigure 1 2D Ultrasound at 21 weeks gestationIntroductionUltrasound diagnosis of fetal anomalies is not alwaysstraightforward. There are situations that are ‘black andwhite’, however, some ultrasound findings leave both theclinician and the patient in a ‘grey area’, the implications ofwhich are uncertain. This case report of abnormal feet is agood example.Case reviewA 29-year-old gravida 2 para 1 in her second pregnancyhad her first ultrasound at 19 weeks gestation. This was afetal anatomy scan, which revealed an isolated finding oflateral ventricles at the upper limits of normal (1.0 cm). Thepatient was referred to our unit two weeks later where weconfirmed that finding, and in addition diagnosed bilateralfeet deformities. It was unclear whether they were ectrodactylyin nature or fusion deformities. Two dimensionalultrasound images of both feet are demonstrated in Figures1 and 5. The fetal anatomy scan appeared otherwise normal.Further investigations revealed a normal karyotype and anegative TORCH screen. Antenatal genetic counselling wasinconclusive.Subsequent ultrasounds were essentially unchangeduntil 28 weeks gestation, when there was a marked increasein the size of the lateral ventricles to 2.0 cm. The right kidneywas noted to have pelvicalyceal dilatation with a dilatedright ureter. The left kidney was normal.Three-dimensional imaging of the fetal feet demonstratedthe abnormalities more clearly, particularly of the rightfoot (Figures 3 and 7). Postnatal photographs and x-rays areFigure 2 2D Ultrasound at 28 weeks gestationshown in Figures 4, 8 and 9.Ultrasounds at 32, 36 and 37 weeks gestation providedno additional information on the feet anomalies, however,they showed a gradual increase in dilatation of the lateralventricles up to 2.7 cm.Postnatal examinationsA live female baby was delivered by planned caesareansection at 38 weeks gestation in Nepean Hospital. Postnatalx-rays, MRI and ultrasound demonstrated the followingfindings:Head: Circumference above the 90th percentile withenlarged ventricles and agenesis of the corpus callosum.Heart: Patent foramen ovale.Limbs: Bilateral polysyndactyly of hands and feet.Kidneys: Right duplex collecting system withobstructed upper pole moiety and a normal left kidney.Hips: Bilateral mild-moderate hip dysplasia.Postnatal genetic review was important in reaching adifferential diagnosis.DiscussionThe incidence of major limb anomalies in newborns is 2 in1000 1 . Anomalies of the toes and metatarsals may be classifiedinto five broad categories including:Absence deformities : Ectrodactyly;Syndactyly;Polydactyly;Brachydactyly; andContracture deformities 2 .ASUM Ultrasound Bulletin 2005 August; 8 (3)15