Background: Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications. Although long-term trends are available at the national level, they are less clear for population subgroups, especially those with middle or low income and also at high risk of obesity.
Method: We conducted a retrospective study among women aged 15-50 years with live deliveries between January 1, 1997, and December 31, 2009, at the Louisiana State University Health Care Services Division hospital system. Pregnancies and GDM cases were identified by using ICD-9 code from the Louisiana State University Hospital-Based Longitudinal Study database. The annual incidence of GDM and its standard error (SE) were calculated and stratified by age group and race.
Results: A total of 2751 GDM incident cases were identified among 62,685 pregnancies between 1997 and 2009. The crude incidence of GDM increased from 4.1% in 1997 to 4.4% in 2009 (increased by 7.3%), and the age-standardized incidence of GDM increased from 5.8% to 7.5% (increased by 29.3%). The incidence of GDM increased with age and reached a peak at 35-39 years of age and then declined in women who were 40-50 years old. Among the three studied races, Asians had significantly higher incidence of GDM than whites and African Americans.
Conclusions: The incidence of GDM increased in most years from 1997 to 2009 and reached a peak in 2002 in the women served by Louisiana State University Health Care Services Division hospitals. GDM has become an important public health problem, particularly among women aged 35-39 years.