Ethnic differences in gestational oral glucose screening in a large US population.

OBJECTIVE: To estimate gestational diabetes mellitus (GDM) prevalence and hyperglycemia in a large multi-ethnic population and evaluate the differences in glucose measures by age and ethnicity. PARTICIPANTS AND SETTING: All singleton births in Kaiser Permanente Hawaii (KPH) during 1995-2003. MEASUREMENTS: Ethnicity classifications from birth certificate data were linked to KPH's electronic medical records that included laboratory-screening results. GDM screening was performed using the 50-g, 1-hour oral glucose challenge test (CCT) and the 100-g, 3-hour oral glucose tolerance test (OCTT). GDM was ascertained by both the National Diabetes Data Group (NDDG) and the Carpenter and Coustan (C&C) thresholds. RESULTS: 21,130 (96%) of all pregnant women were screened for GDM using the 1-hour GCT: 21% had glucose levels exceeding the threshold of 140 mg/dL, with the highest rates in Filipinos and Chinese. African American and Caucasian groups had the lowest elevated glucose. Of those with elevated glucose, 1.3% had levels >200 mg/dL, were considered to have GDM, and not tested further; 88% underwent the 3-hour OGTT. Age-adjusted GDM prevalence was 4.4% (NDDG) and 6.6% (C&C). Koreans (6.2%) and Filipinos (6.1%) had the highest age-adjusted NDDGC GDM. African Americans (1.5%), Caucasians (2.5%), and Vietnamese (2.8%) had the lowest. CONCLUSIONS: This is the first population-based study to report GDM prevalence in a large group of ethnicities represented in Hawaii. We found very diverse rates of GDM prevalence and elevated glucose among these groups. These findings point to the need for further research along several avenues, such as maternal-child outcome differences and perhaps ethnic-specific guidelines for GDM diagnosis.

Excess gestational weight gain: modifying fetal macrosomia risk associated with maternal glucose.

OBJECTIVE: To estimate how maternal weight gain and maternal glucose relate to fetal macrosomia risk (greater than 4,000 g) among a population universally screened for gestational diabetes mellitus (GDM). METHODS: Between 1995 and 2003, 41,540 pregnant women in two regions (Northwest/Hawaii) of a large U.S. health plan had GDM screening using the 50-g glucose challenge test; 6,397 also underwent a 3-hour, 100-g oral glucose tolerance test. We assessed the relationship between level of maternal glucose with glucose screening and fetal macrosomia risk after adjustment for potential confounders, including maternal age, parity, and ethnicity and sex of the newborn. We stratified by maternal weight gain (40 lb or fewer compared with more than 40 lb) because excessive maternal weight gain modified results. RESULTS: Among women with both normal and abnormal GDM screenings, increasing level of maternal glucose was linearly related to macrosomia risk (P<.001 for trend in all groups). Women with excessive weight gain (more than 40 lb) had nearly double the risk of fetal macrosomia for each level of maternal glucose compared with those with gestational weight gain of 40 lb or fewer. For example, among women with normal post-glucose challenge test glucose levels (less than 95 mg/dL) and excessive weight gain, 16.5% had macrosomic newborns compared with 9.3% of women who gained 40 lb or fewer. Moreover, nearly one third of women (29.3%) with GDM who gained more than 40 lb had a macrosomic newborn compared with only 13.5% of women with GDM who gained 40 lb or fewer during pregnancy (P=.018). CONCLUSION: Excessive pregnancy weight gain nearly doubles the risk of fetal macrosomia with each increasing level of maternal glucose, even among women with GDM. LEVEL OF EVIDENCE: II.

Childhood obesity and metabolic imprinting: the ongoing effects of maternal hyperglycemia.

OBJECTIVE: The purpose of this study was to determine how the range of measured maternal glycemia in pregnancy relates to risk of obesity in childhood. RESEARCH DESIGN AND METHODS: Universal gestational diabetes mellitus (GDM) screening (a 50-g glucose challenge test [GCT]) was performed in two regions (Northwest and Hawaii) of a large diverse HMO during 1995-2000, and GDM was diagnosed/treated using a 3-h 100-g oral glucose tolerance test (OGTT) and National Diabetes Data Group (NDDG) criteria. Measured weight in offspring (n = 9,439) was ascertained 5-7 years later to calculate sex-specific weight-for-age percentiles using U.S. norms (1963-1994 standard) and then classified by maternal positive GCT (1 h >or= 7.8 mmol/l) and OGTT results (1 or >or=2 of the 4 time points abnormal: fasting, 1 h, 2 h, or 3 h by Carpenter and Coustan and NDDG criteria). RESULTS: There was a positive trend for increasing childhood obesity at age 5-7 years (P < 0.0001; 85th and 95th percentiles) across the range of increasing maternal glucose screen values, which remained after adjustment for potential confounders including maternal weight gain, maternal age, parity, ethnicity, and birth weight. The risk of childhood obesity in offspring of mothers with GDM by NDDG criteria (treated) was attenuated compared with the risks for the groups with lesser degrees of hyperglycemia (untreated). The relationships were similar among Caucasians and non-Caucasians. Stratification by birth weight also revealed these effects in children of normal birth weight (