The medical management of gestational diabetes in Australia within a solo private practice

Twin pregnancy outcomes for women with gestational diabetes mellitus compared with glucose tolerant women

OBJECTIVE

To examine pregnancy outcomes for women with gestational diabetes mellitus (GDM) and a twin pregnancy compared with glucose tolerant women with a twin pregnancy.

DESIGN

Comparison of selected pregnancy outcomes.

SETTING

Wollongong, New South Wales, Australia.

POPULATION

Women with GDM seen over a 10-year period by an endocrinologist, and women from a selected year of an obstetric database including Wollongong and Shellharbour Hospitals.

METHODS

Examination of pregnancy outcome data from the two sources.

MAIN OUTCOME MEASURES

Fetal birthweights and method of delivery.

RESULTS

There were 28 GDM women with a twin pregnancy from 1229 consecutive referrals (2.3%) of women with GDM for medical management. For comparison there were 29 glucose tolerant women with twin pregnancies evaluable who had delivered over a 1-year period. For the women with GDM and a twin pregnancy there were no significant differences in demographics or outcomes except for a higher rate of elective Caesarean section.

CONCLUSION

The higher rate of Caesarean section appeared to be related to the combination of a twin pregnancy and GDM rather than the twin pregnancy or the GDM independently.

The metabolic profile of glucose tolerant women who have had large for gestational age babies

The possibility has been raised that women who have had large for gestational age infants, while glucose tolerant during pregnancy by conventional testing, may still have a subtle abnormality of carbohydrate metabolism. We have examined, some time after the completion of a pregnancy, the fasting levels of glucose, insulin and lipids in a group of women, glucose tolerant during pregnancy, who had a large for gestational age infant compared to a very carefully matched control group of women who had an appropriate for gestational age infant. No significant differences were found. These findings suggest that women who have a large for gestational age infant do so for a variety of reasons not related to maternal carbohydrate metabolism.

Is there a seasonal variation in the incidence of gestational diabetes?

It has been suggested that the incidence of gestational diabetes (GDM) may vary with different seasons of the year. The fasting and 2 h glucose levels after a 75 g glucose tolerance test were therefore examined in 2749 women being tested for GDM and were correlated with the mean temperature at 0900 h by month and by season. The mean monthly temperature ranged from 22.3 degrees C in January to 13.6 degrees C in July. The monthly incidence of GDM ranged from 3.5% (95% CI, 0.7-6.3) in September to 8.7% (4.7-12.7) in November. The seasonal incidence of GDM ranged from 7.4% (5.6-9.2) in autumn to 5.5% (3.5-7.5) in winter. Chi-squared analysis did not suggest a significant association between the proportion of women diagnosed with GDM and either the month (p = 0.47) or the season (p = 0.39). Multiple regression analysis, after correction for maternal age, parity, BMI, and the week of testing revealed a non-significant association between fasting glucose and monthly temperature (p = 0.36) and an increase in the 2 h glucose of 0.026 mmol l-1 for each increase of 1 degree C in temperature (p = 0.011). In a temperate coastal area of Australia these differences do not appear clinically significant and have not caused a variation in the incidence of GDM with different seasons.