Placental hormones during induced hypoglycaemia in pregnant women with insulin-dependent diabetes mellitus:: evidence of an active role for placenta in hormonal counter-regulation

Objective To study the effect of induced hypoglycaemia on serum levels of the placental hormones oestriol, human placental lactogen, placental growth hormone and progesterone in the third trimester of pregnancy. Design A prospective experimental investigation. Setting High risk pregnancy unit and diabetes research unit at Karolinska Institutet Danderyd Hospital, a university hospital. Participants Ten women with insulin-dependent diabetes mellitus in the third trimester of pregnancy. Methods Venous blood samples were collected every 15 minutes for analyses of oestriol, progesterone, human placental lactogen and placental growth hormone, during the 150 min of a hyperinsulinaemic hypoglycaemic clamp, which maintained arterial blood-glucose level of about 2.2 mmol/l. Main outcome measures Levels of analysed placental hormones during hypoglycaemia. Results A statistically significant increase was observed in placental growth hormone during hypoglycaemia (P < 0.0001), whereas the placental hormones progesterone, human placental lactogen and oestriol did not show changes of clinical significance. Conclusions The increase in placental growth hormone indicates that the placenta is an endocrine organ which may take an active part in acute metabolic processes, such as here in the hormonal counterregulation of hypoglycaemia.