Self monitoring of capillary blood glucose in diabetic pregnancy

Abstract

AbstractHome monitoring of capillary blood glucose is now a well‐established feature of pregnancy in the diabetic woman. We have analysed the data from 48 pregnancies to determine if reasons could be found why some mothers achieved better blood glucose control than others.A mean weekly pre‐prandial blood glucose was calculated for each week from the date of first booking (from the estimated date of conception in some).No difference in age, weight, age at onset of diabetes or duration of diabetes was found between those diabetic mothers who achieved excellent (all weekly means <6 mmol/l), intermediate, or only fair blood glucose control (weekly mean blood glucose >6 mmol/l on more than six of the weeks monitored). The blood HbA1 values related best to mean capillary blood glucose in the third trimester but were always lowest in those with excellent mean blood glucose values. Insulin resistance is increased during both normal and diabetic pregnancy: a calculated “insulin‐resistance” factor (ratio of mean total insulin dose to mean capillary blood glucose) showed this to be higher in the less well controlled patients. This may represent the effect of further insulin resistance due to food intake in excess of requirement, or to the efkfect of the persistent hyperglycaemia itself. Optimum control of blood glucose will not always guarantee a normal fetal outcome, but frequent self‐monitoring has provided the means to assess factors influencing hyperglycaemia in pregnancy.