Transient abnormal myelopoiesis associated with Down syndrome presenting as severe hydrops fetalis: a case report.

We present a case of transient abnormal myelopoiesis (TAM) presenting as non-immune fetal hydrops (NIHF). Hydrops fetalis (HF) is a condition associated with very high perinatal mortality, especially when no treatable cause, such as fetal anaemia, exists. In fetuses prior to 24 weeks with NIHF, a chromosomal anomaly is a common association. TAM is a leukaemic condition, almost entirely limited to children with Down syndrome. The presentation of TAM prenatally is unusual but cases may present ultrasonographically with NIHF and associated fetal hepatosplenomegaly. We report a case presenting in this manner with NIHF detected at 29 weeks' gestation and discuss the subsequent diagnosis and management of in utero TAM.