Perinatal mortality in Type 2 diabetes mellitus

Aims In many parts of the world the number of pregnancies in women with Typ e 2 diabetes mellitus IDM) now exceeds that in women with Type 1 DM, but th ere are few data published on perinatal mortality in Type 2 DM. This study reports observational data on perinatal mortality in Type 2 DM from a popul ation with a high background rate of this disorder. Methods Over a 12-year period (1985-1997) at the Diabetes Clinic at Nationa l Women's Hospital, Auckland, there were 434 pregnancies in women with Type 2 DM (256 known and 178 diagnosed with gestational diabetes mellitus (GDM) , but confirmed to have Type 2 DM early post-partum), 160 pregnancies in wo men with Type 1 DM and 932 in women with GDM. Perinatal mortality was class ified as either intermediate fetal death (20-28 weeks' gestation), late fet al death (28 weeks' gestation to term) or early neonatal death (up to 1 mon th post-partum). Results The perinatal mortality in Type 2 DM was 46.1/1000, significantly h igher than the rates for the general population (12.5), Type 1 DM (12.5) an d GDM (8.9) (P < 0.0001). Congenital malformations accounted for only 10% o f the perinatal mortality. There was a seven-fold increase in the rate of l ate fetal death and 2.5-fold increase in the rates of intermediate fetal an d late neonatal death. Subjects with Type 2 DM were significantly older and more obese than subjects with Type 1 DM, and presented later to the diabet es service. Conclusions Perinatal mortality in Type 2 DM is significantly increased, ma inly owing to an excess of late fetal death. Maternal factors such as obesi ty may be important contributors to the high perinatal mortality. Women dia gnosed with GDM who have unrecognized Type 2 DM are also at high risk, but perinatal mortality is low in women with milder degrees of glucose intolera nce in pregnancy.