Introduction
Diabetes is recognized as one of the most common metabolic disorders of pregnancy affecting 17% of pregnancies globally.1Gestational diabetes mellitus (GDM), a condition defined by the American College of Obstetrics and Gynecology as carbohydrate intolerance during pregnancy, comprises most cases of pregnancy-associated diabetes.2 Data suggest that approximately 86% of pregnancy-associated diabetes is caused by GDM, while about 14% is due to diabetes diagnosed prior to pregnancy.1 In part due to the greater prevalence of GDM compared to pre-pregnancy diabetes (PDM), the majority of research on pregnancy-associated diabetes has focused on maternal morbidity and fetal outcomes among women with GDM. We know from previously published data that women diagnosed with GDM have an increased risk for several adverse outcomes including stillbirth, fetal overgrowth, preterm birth, preeclampsia and progression to type 2 diabetes later in life.3–5 Data also suggest that children born to mothers with GDM are at increased risk for obesity, cardiovascular disease and type 2 diabetes later in life.3,4 Women with PDM are reported to be at a significantly increased risk for preeclampsia, congenital malformations, fetal overgrowth and fetal death.6-16 These data raise serious concerns given that the number of women with PDM is increasing, irrespective of diabetes subtype (type 1 insulin-dependent, or type 2 non-insulin dependent).6,9,10,17
The risks accompanying pregnancy-associated diabetes have been reported to disproportionately impact women from different races/ethnicities. Some studies have indicated that non-Caucasian races/ethnicities have a higher prevalence of PDM and GDM than Caucasian women.9,18–20 Consequently, women of different racial and ethnic backgrounds, such as Black and South Asian with PDM and GDM, have also been shown to be at an increased risk for adverse fetal outcomes including perinatal loss, preterm delivery, respiratory distress syndrome and fetal anomalies.21–23 However, the majority of these studies focused solely on GDM and assessed women from a limited geographic region. As a result, these data highlight the need for further research to better characterize existing racial/ethnic disparities.
We sought to expand the depth and breadth of the current understanding of racial and ethnic differences in the prevalence of both PDM and GDM, by using hospital data to examine national trends in prevalence by race/ethnicity. We also examined the association between these conditions, race/ethnicity and stillbirth.