Pregnancy outcomes according to the definition of gestational diabetes.

OBJECTIVE: To assess the frequency and perinatal outcomes of gestational diabetes mellitus (GDM) defined by the criteria according to the International Association of Diabetes in Pregnancy Study Group (IADPSG) and the National Institute for Health and Care Excellence (NICE) diagnostic criteria for GDM. DESIGN: A retrospective cohort study. SETTING: Six secondary and tertiary delivery hospitals in Finland in 2009. POPULATION: Pregnant women (N = 4,033) and their offspring. METHODS: We used data on comprehensive screening of pregnant women with a 2-h 75-g oral glucose tolerance test (OGTT), performed between gestational weeks 24 and 40. OGTT glucose concentrations were used to identify women who fulfilled IADPSG and NICE criteria. While cut-offs according to Finnish national criteria partly overlapped with both criteria, a subgroup of IADPSG- or NICE-positive GDM women remained undiagnosed by Finnish criteria and hence non-treated. They were analysed as subgroups and compared to controls who were negative with all cut-offs. MAIN OUTCOME MEASURES: GDM prevalence, birth weight SD score (BWSDS), large for gestational age (LGA) and caesarean section (CS) rates. RESULTS: Among the 4,033 women screened for GDM, 1,249 (31.0%) and 529 (13.1%) had GDM according to the IADPSG and NICE criteria, respectively. The LGA rate was similar in both groups. Regardless of the diagnostic criteria, women with GDM had a higher risk of induced delivery and CSs than controls. In IADPSG-positive non-treated women, offspring's BWSDS and CS rate were higher than in controls. CONCLUSIONS: GDM prevalence was 2.4-fold higher according to the IADPSG compared with the NICE criteria but the LGA rate did not differ. BWSDS and CS rate were increased already with mild untreated hyperglycaemia.

Independent and concomitant associations of gestational diabetes and maternal obesity to perinatal outcome: A register-based study.

AIMS: Gestational diabetes (GDM) is often accompanied by maternal overweight. Our aim was to evaluate the separate and concomitant effects of GDM and maternal overweight/obesity on perinatal outcomes. METHODS: We used the Finnish Medical Birth Register to identify all 24,577 women with a singleton pregnancy who delivered in 2009 in Finland and underwent an oral glucose tolerance test (OGTT). Women were divided into groups according to the result of OGTT (GDM/no GDM) and pre-pregnancy body mass index (BMI): normal weight (≤24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2). Primary outcomes included macrosomia, caesarean delivery, and treatment at neonatal ward. Normal weight women without GDM constituted the reference group. RESULTS: Compared to reference group, overweight or obese women without GDM had an increased risk of macrosomia [odds ratio adjusted for age, parity, smoking and socio-economic status (aOR)1.18 (95% CI 1.09-1.28) and 1.50 (95% CI 1.19-1.88)], and caesarean delivery [aORs 1.17 (95% CI 1.07-1.28) and 1.52 (95% CI 1.37-1.69)], respectively. In normal weight GDM women the risk of macrosomia [aOR 1.17 (95% CI 0.85-1.62)] and caesarean delivery [aOR 1.10 (95% CI 0.96-1.27)] was not significantly increased as compared to normal weight women without GDM. GDM increased the risk of treatment at neonatal ward in all BMI categories and maternal obesity without GDM was also a risk factor for treatment at neonatal ward. Interaction p values between BMI and GDM on these outcomes were <0.001. CONCLUSIONS: Maternal overweight and obesity without GDM increased the risk of macrosomia and caesarean delivery when compared to the reference group. These risks were amplified when overweight/obesity was accompanied by GDM. Obesity without GDM was a risk factor for treatment at neonatal ward; GDM increased this risk in all BMI categories. Our results suggest that especially maternal obesity should be considered as a risk factor for adverse pregnancy outcomes and GDM further amplifies this risk.

Towards national comprehensive gestational diabetes screening - consequences for neonatal outcome and care.

INTRODUCTION: The change from risk-factor-based to nearly comprehensive screening of gestational diabetes (GDM) identifies more but milder cases of the disease. The main aim of this study was to evaluate the effect of this screening policy change on neonatal outcomes and care. MATERIAL AND METHODS: A population-based register study in Finland. GDM cases during risk-factor-based (year 2006, n = 5179) and comprehensive (2010, n = 6679) screenings were identified through the Medical Birth Register. All singletons without maternal GDM or prepregnancy diabetes served as controls (n = 51 746 and n = 52 386, respectively). The main outcomes were macrosomia, neonatal hypoglycemia and the need for care in a neonatal ward. RESULTS: In the GDM group, the mean birthweight decreased between the study years from 3660 g to 3595 g and the prevalence of macrosomia from 5.6 to 4.1% even after adjustment for maternal age, parity and prepregnancy body mass index. The adjusted mean difference in birthweight between GDM and control newborns decreased from 70 to 22 g between the study years. The prevalence of neonatal hypoglycemia increased from 18.0 to 22.1% in the GDM group. However, neonatal hypoglycemia was more often treated without care in a neonatal ward. The proportion of infants treated on a neonatal ward decreased in both the GDM and control groups between the study years. CONCLUSIONS: In newborns, comprehensive GDM screening led to decreased mean birthweight and macrosomia rates, but the prevalence of neonatal hypoglycemia increased. This places substantial demands for delivery hospitals and healthcare resources.

The changing face of gestational diabetes: the effect of the shift from risk factor-based to comprehensive screening.

OBJECTIVE: To evaluate the effect of the change in the gestational diabetes (GDM) screening policy from risk-factor based to comprehensive screening on the prevalence and type of GDM and characteristics of GDM pregnancies. DESIGN: Population-based register study in Finland. Subjects were GDM women who gave birth before (2006, n=5185) and after (2010, n=6683) the policy change. All the other women in those years without pre-pregnancy diabetes acted as controls (51 759 and 52 398 respectively). METHODS: GDM women with singleton pregnancy were identified through The Finnish Medical Birth Register by abnormal oral glucose tolerance test or initiation of insulin. Main outcome measures were prevalence of GDM (total and insulin/diet-treated), and caesarean section rate. RESULTS: The proportion of screened mothers increased from 27.5 to 51.3% and the total prevalence of GDM from 9.1 to 11.3%. This increase consisted mainly of diet-treated mothers, while the number and proportion of insulin-treated mothers decreased (21.8% vs13.3%, P<0.001). The proportion of primiparous women increased (34.5-39.4%, P<0.0001) and mean pre-pregnancy BMI decreased (28.6-28.2, P<0.001). The overall caesarean section rate remained the same but increased among women with GDM (20.8-22.1%) adjusted odds ratios being 1.22 (95% CI 1.14, 1.31) during comprehensive and 1.10 (95% CI 1.02, 1.19) during risk factor-based screening. CONCLUSIONS: The shift to comprehensive screening led to a significant increase in women with GDM, who were more often primiparous and had a lower BMI. Comprehensive screening did not perform better in diagnosing women needing insulin treatment.