Background and objective: Diabetes can complicate pregnancy but it is not the major complication of pregnancy. Though prevalence of diabetes is alarmingly high among Indians there have been very few studies assessing the effect of diabetes on pregnancy outcomes, particularly comparing pre-gestational diabetes mellitus [PGDM] and gestational diabetes [GDM] with non-diabetic mothers.
Methods: Pregnant women attending the Dr. Mohan's Diabetes Specialities Centre, a tertiary care centre for diabetes in Chennai in southern India were selected for the study. PGDM and GDM were defined using standard criteria. Out of the 245 pregnant women with diabetes registered at the centre, follow up data was available for 225, which included 79 PGDM and 146 GDM subjects. Non-diabetic controls (n=30) were recruited from the ongoing population based study the Chennai Urban Rural Epidemiology Study (CURES). Details of outcome variables including abortions, mode of delivery, congenital anomalies and neonate's birth weight were documented.
Results: Women with PGDM had significantly higher fasting plasma glucose [p<0.001] and fructosamine [p<0.001] levels compared to GDM. Proportion of women who underwent abortions was 0% in non-diabetic controls, 10.1% in PGDM and 2.7% in GDM and the difference between PGDM and GDM was statistically significant [p = 0.04]. Prevalence of 'low birth weight' babies in the study groups were, 14.3% in non-diabetic mothers, 12.3% in PGDM and 8.2% in GDM. The prevalence of 'large babies' was higher in GDM [27.6%] and PGDM [19.2%] groups compared to non-diabetic controls [7.1%] but the differences reached statistical significance only in the GDM group [p = 0.04]. Prevalence of congenital anomalies was 0% among non-diabetic controls, 3.8% in PGDM and 1.4% in GDM but the differences did not reach statistical significance. A significant increase in frequency of abortions [trend chi square = 5.67, p = 0.017] and 'low birth weight' babies [trend chi square = 4.761,p = 0.029] was observed with increasing fructosamine levels in the diabetic mothers.
Conclusion: Women with diabetes have worse pregnancy outcomes compared to non-diabetic mothers with and those with pre-gestational diabetes fare worse than those with gestational diabetes. The study emphasizes the fact that strict glycemic control is extremely important during pregnancy.