English summary: SELF MONITORING OF BLOOD GLUCOSE IMPROVES THE OUTCOME OF GESTATIONAL DIABETES

Background Gestational diabetes is defined as a disorder of glucose metabolism diagnosed during pregnancy. It carries a risk of perinatal complications for the mother and infant, which may be reduced by treatment of the hyperglycaemia. The prevalence of gestational diabetes in Finland is estimated at 10-12% of pregnant women. The known risk factors for gestational diabetes are maternal overweight, family history of diabetes, previous gestational diabetes, and maternal age over 40 years, along with an antecedent birth weight exceeding 4500 g. The principal treatment of gestational diabetes is diet, but some patients require insulin. Self-monitoring of blood glucose has been used by those on insulin treatment. The aim of our study was to find out whether the outcome of all gestational diabetes patients could be improved by self-monitoring of blood glucose.

Methods In our prospective study pregnant women with risk factors for gestational diabetes were given an oral two-hour glucose (75 g) test in their second trimester (26-28 weeks). Randomisation of the patients to blood glucose self-monitoring or controls was based on the patients' living area. The decision about insulin treatment was based on the self monitoring of blood glucose among those in the study group and on two laboratory measurements of blood glucose in the control group.

Results Insulin treatment was started in 19% of cases in the study group and in 5% of the controls. Birth weight was 3571 ± 492 g in the study group and 3705 ± 481 g in the control group (p=0.006). Birth weight over 4500 g was found in 2% vs. 4% respectively. Macrosomia was not found in those with insulin treatment.

Conclusions Self-monitoring of blood glucose is an effective method in the treatment of gestational diabetes. Those who need insulin treatment can be readily identified and the risk of macrosomia is decreased. Self-monitoring of blood glucose in gestational diabetes is feasible in health centre maternity clinics.