ultrasound diagnosis of fatal anomalies

CHROMOSOMAL DISORDERS
Trisomy 9, Partial Trisomy 9 p
Definition: An extra triple chromosome 9,
frequently as trisomy 9 p. It is associated with
multiple anomalies. Usually occurs as mosaic
forms, as pure trisomy usually leads to early fetal
demise.
First described in 1973 by Feingold and Atkins.
Ultrasound findings: Growth restriction. Head
and face: microcephaly, cerebellar anomaly, ventriculomegaly,
Dandy–Walker cysts, neural tube
defect, facial clefts, micrognathia, microphthalmia.
Extremities: flexion anomaly of the fingers,
abnormal fixation of the feet. Thorax and
abdomen: cardiac anomaly, liver calcification,
singular umbilical artery, renal anomalies, maldescent
of the testis.
Differential diagnosis: Trisomy 13, trisomy 18,
Wolf–Hirschhorn syndrome, triploidy
Prognosis: Intrauterine demise or neonatal
death is the frequent outcome. Survivors are
severely mentally impaired. In mosaic forms, the
severity depends on the percentage of affected
cells and the organ systems involved.
Fig. 9.12 Trisomy 9. Widening of the cerebellomedullary
cistern at 16+1weeks(Dandy–Walker
variant).
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Fig. 9.13 Trisomy 9. Echogenic kidneys, with dilation
of renal pelvis as well as fetal ascites at
16+1weeks.
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