Incidence of cardiomegaly in stillborn infants of diabetic mothers

Abstract

NOREEN RUSSELL, PETER HOLLWAY, STEPHEN QUINN, PETER KELEHAN, MICHAEL FOLEY, FIONNUALA MCAULIFFE, NationalMaternityHospital,Dublin, Ireland, University College Dublin, Obstetrics and Gynaecology, Dublin, Ireland OBJECTIVE: The role of cardiomegaly in the risk of sudden unexplained death in-utero is unclear. The study hypothesis is that cardiomegaly in the fetus contributes to the risk of sudden death in –utero. The aim of the study is to report the incidence of cardiomegaly in stillborn normally formed infants of diabetic mothers and to compare this with the incidence of cardiomegaly in stillborn normally formed macrosomic infants (O90th centile) and stillborn normally formed appropriately grown infants (10-90th centile) without abruption and for whom no cause of stillbirth was identified. STUDY DESIGN: This is a retrospective study of hospital annual reports from 1985 to 2002 with institutional ethics approval. Cardiomegaly was defined as greater than 2 standard deviations above the mean weight for that gestational age (Wigglesworth et al). Additionally blinded to the clinical details, the pathologists (PH and PK) reviewed the histology slides to record the presence or absence of myocardial fibre disarray, a known feature of cardiomyopathy in adults. RESULTS: Over this 17 year period there were 28 stillborn infants in mothers with either insulin dependant diabetes or gestational diabetes, 26 of these had post-mortem examination. Of these 26, 7 had evidence of cardiomegaly (27%). There were 19 stillborn infants that were macrosomic without maternal diabetes and 5 of these had cardiomegaly on post-mortem (26%). None of the stillborn infants that were appropriately grown had evidence of cardiomegaly (0/103). Stillborn macrosomic and stillborn infants of diabetic mothers were more likely to show cardiomegaly on post-mortem (p!0.01). Myocardial disarray was evident in only 1 case of diabetic cardiomegaly, suggesting that this histological parameter is not a feature of diabetic cardiomyopathy. CONCLUSION: Cardiomegaly may contribute to the risk of fetal death in macrosomic infants and infants of diabetic mothers. Myocardial disarray does not appear to be a constant histological characteristic of diabetic related fetal cardiomegaly.