Endocrine Abstracts

In diabetic pregnancy good outcomes can be achieved by meticulous glycaemic control prior to and during pregnancy. However, national and regional audits indicate the difficulties in getting optimal results in comparison to the background population. Despite great efforts by mothers and their diabetes care teams, the babies are often large for gestational age (Mean birthweight 3427g, 86 %> 50%ile, 55% > 90%ile) and are delivered early (Median gestational age 37weeks) by caesarian section (64%). Metabolic, hormonal and fat distribution studies on neonates provide some explanations for fetal adiposity.

Perinatal mortality (27.8 per 1000) has reduced in recent years, but offspring still have more congenital abnormalities (Congenital anomaly rate 60- 97 / 1000 vs. 28 /1000). The miscarriage rate is 14.7%. The risk of stillbirth (18.5 -25 / 1000) and infant mortality ((14.2 - 58.5 / 1000) remain well in excess of the non diabetic population. Some evidence suggests infants may be at risk of metabolic problems in later life.

Animal studies show that the metabolic environment of the developing fetus and fetal genes influence the malformation rate. In clinical practice a comprehensive pre-pregnancy care package, to address all risk factors for malformation, will reduce congenital anomalies and other adverse outcomes.

Maintaining very tight control throughout pregnancy can prove difficult. The management of acute (Diabetic Ketoacidosis 8.7%, Severe Hypoglycaemia 40%) and chronic complications of diabetes (Proteinuria 12.4%, Proliferative Retinopathy 22.5%) are challenging and require individualized solutions underpinned by knowledge of maternal physiology and metabolism. Trials are underway to investigate interventions to reduce adverse maternal outcomes such as pre- eclampsia

An understanding of the interrelationships between maternal diabetes, placental and fetal development has helped to guide good clinical practice.