Introduction Kasabach-Merritt Syndrome (KMS) is a rare complication of a vascular tumour resulting in consumptive coagulopathy, anaemia and thrombocytopenia. While haemangiomas are common tumours of the first year of life, KMS has rarely been described in fetal life. The aim of this study was to review cases of fetal KMS in order to meaningfully study this rare, complex and devastating complication.

Methods Retrospective cohort of all fetal KMS in a large tertiary level unit in Toronto (1992–2013), with literature review of all cases of fetal KMS.

Results Two cases of fetal KMS were identified in this unit and twelve on review of the literature. On reviewing all fourteen cases, the median gestational age of diagnosis was 31 weeks (14–37 weeks) and median GA of delivery of 34 weeks (30–39 weeks). Seven affected fetuses underwent fetal blood sampling (FBS).

Eleven infants were delivered by caesarean section, with one vaginal delivery following intrauterine death and two where the prognosis was considered to be dismal; both of these infants died after birth. Five other infants died shortly after delivery despite intensive neonatal care, giving an overall mortality of 57%. Amongst the survivors all required multiple transfusions and intensive neonatal care. One infant required an amputation of the left leg and two infants required surgical resection of the mass after unsuccessful medical treatment.

Conclusion KMS is an important but uncommon complication of fetal haemangioma with a high rate of morbidity and mortality.