A simplified oral glucose tolerance test in pregnancy: compliance and results

Oral glucose tolerance test-The imperfect gold standard for gestational diabetes screening: A qualitative study involving clinicians in regional, rural and remote areas of Western Australia

ISSUE ADDRESSED

The oral glucose tolerance test is the 'gold standard' for detecting gestational diabetes in Australian and International guidelines. Test completion in regional, rural and remote regions may be as low as 50%. We explored challenges and enablers for regional, rural and remote antenatal clinicians providing gestational diabetes screening to better understand low oral glucose tolerance test completion.

METHODS

We conducted a qualitative descriptive study using semi-structured interviews. Participants eligible for the study were doctors or midwives providing antenatal care in regional, rural and remote Western Australia, between August 2019 and November 2020. Interviews were recorded digitally and transcribed into a Word document. We conducted a thematic analysis after initial categorisation and deduction of themes through workshops involving the research team.

RESULTS

We found a diversity of viewpoints on oral glucose tolerance test reliability for detecting gestational diabetes. Themes that emerged were; good collaboration between antenatal clinicians is required for successful screening; screening occurs throughout pregnancy using various tests; clinicians make significant efforts to address barriers; clinicians prioritise therapeutic relationships.

CONCLUSIONS

Effective universal screening for gestational diabetes in regional, rural and remote Western Australia is difficult and more complex in practice than guidelines imply. Detecting gestational diabetes requires creative solutions, early identification of at risk women and trust and collaboration between clinicians and women. SO WHAT?: Detection of gestational diabetes in regional, rural and remote Western Australia remains poorly completed. New strategies are required to adequately identify women at risk of adverse birth outcomes relating to hyperglycaemia in pregnancy.

Association Between History of Adverse Pregnancy Outcomes and Coronary Artery Disease Assessed by Coronary Computed Tomography Angiography

IMPORTANCE

Adverse pregnancy outcomes are recognized risk enhancers for cardiovascular disease, but the prevalence of subclinical coronary atherosclerosis after these conditions is unknown.

OBJECTIVE

To assess associations between history of adverse pregnancy outcomes and coronary artery disease assessed by coronary computed tomography angiography screening.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of a population-based cohort of women in Sweden (n = 10 528) with 1 or more deliveries in 1973 or later, ascertained via the Swedish National Medical Birth Register, who subsequently participated in the Swedish Cardiopulmonary Bioimage Study at age 50 to 65 (median, 57.3) years in 2013-2018. Delivery data were prospectively collected.

EXPOSURES

Adverse pregnancy outcomes, including preeclampsia, gestational hypertension, preterm delivery, small-for-gestational-age infant, and gestational diabetes. The reference category included women with no history of these exposures.

MAIN OUTCOMES AND MEASURES

Coronary computed tomography angiography indexes, including any coronary atherosclerosis, significant stenosis, noncalcified plaque, segment involvement score of 4 or greater, and coronary artery calcium score greater than 100.

RESULTS

A median 29.6 (IQR, 25.0-34.9) years after first registered delivery, 18.9% of women had a history of adverse pregnancy outcomes, with specific pregnancy histories ranging from 1.4% (gestational diabetes) to 9.5% (preterm delivery). The prevalence of any coronary atherosclerosis in women with a history of any adverse pregnancy outcome was 32.1% (95% CI, 30.0%-34.2%), which was significantly higher (prevalence difference, 3.8% [95% CI, 1.6%-6.1%]; prevalence ratio, 1.14 [95% CI, 1.06-1.22]) compared with reference women. History of gestational hypertension and preeclampsia were both significantly associated with higher and similar prevalence of all outcome indexes. For preeclampsia, the highest prevalence difference was observed for any coronary atherosclerosis (prevalence difference, 8.0% [95% CI, 3.7%-12.3%]; prevalence ratio, 1.28 [95% CI, 1.14-1.45]), and the highest prevalence ratio was observed for significant stenosis (prevalence difference, 3.1% [95% CI, 1.1%-5.1%]; prevalence ratio, 2.46 [95% CI, 1.65-3.67]). In adjusted models, odds ratios for preeclampsia ranged from 1.31 (95% CI, 1.07-1.61) for any coronary atherosclerosis to 2.21 (95% CI, 1.42-3.44) for significant stenosis. Similar associations were observed for history of preeclampsia or gestational hypertension among women with low predicted cardiovascular risk.

CONCLUSIONS AND RELEVANCE

Among Swedish women undergoing coronary computed tomography angiography screening, there was a statistically significant association between history of adverse pregnancy outcomes and image-identified coronary artery disease, including among women estimated to be at low cardiovascular disease risk. Further research is needed to understand the clinical importance of these associations.

Trends in pregnancy outcomes for women with gestational diabetes mellitus in Sweden 1998-2012: a nationwide cohort study

AIM

To assess whether incidence of maternal and neonatal outcomes for women with or without gestational diabetes mellitus (GDM) have changed over time.

METHODS

Population-based cohort study in Sweden including all singleton pregnancies over the period 1998-2012. GDM was diagnosed following Diabetic Pregnancy Study Group 1991 criteria. Poisson regression or negative binomial regression was used to model yearly relative change in numbers of cases and incidence of the outcomes with 95% confidence intervals (CI), and yearly absolute change in birthweight z-score.

RESULTS

The study included 1 455 667 pregnancies. The number of pregnancies increased over time and the overall prevalence of GDM was 1%. For women with GDM there was a significantly decreasing trend in incidence per year for large for gestational age (LGA) (0.986, 95% CI 0.975 to 0.996), birthweight z-score (-0.012, 95% CI -0.017 to -0.007) and birth trauma (0.937, 95% CI 0.907 to 0.968). The trend for small for gestational age (SGA) among women with GDM increased by an odds ratio per year (1.016, 95% CI 1.002 to 1.029). No significant interaction tests for maternal characteristics were found. Trends in outcomes for women without diabetes were similar to those for women with GDM.

CONCLUSIONS

This study shows that there were improvements in pregnancy outcomes for women with GDM between 1998 and 2012, although the incidence of SGA increased. Improvements followed similar trends in the background population. Inequalities in obstetric outcomes between women with GDM and those without have continued unchanged over 15 years, suggesting that new management strategies are required to reduce this gap.

Diabetes screening in pregnancy failing women in rural Western Australia: An audit of oral glucose tolerance test completion rates

OBJECTIVE

To quantify screening rate for gestational diabetes mellitus and completion of oral glucose tolerance test in rural and remote Western Australia.

DESIGN AND PARTICIPANTS

Retrospective audit of 551 antenatal records from women of 16 years and older without pre-existing diabetes and with singleton pregnancies delivered in 2013.

MAIN OUTCOME MEASURES

Number of women recorded screened for gestational diabetes mellitus in second or third trimester using oral glucose tolerance test or other tests; gestational diabetes mellitus rate.

RESULTS

Only 278 (50.5%) women were screened with oral glucose tolerance test; 113 (20.5%) had no record of any screening related to gestational diabetes mellitus. In a nested mixed-effects logistic regression model, women with a previous gestational diabetes mellitus diagnosis, two or more risk factors (excluding ethnicity) or high-risk gestational diabetes mellitus ethnicity other than Australian Aboriginal were more likely to be screened, while Australian Aboriginal women were less likely to be screened with oral glucose tolerance test. Clinicians reported patient and clinician factors and logistical difficulties as reasons for the oral glucose tolerance test not being completed at their site. Of those screened with oral glucose tolerance test, a high rate of gestational diabetes mellitus was diagnosed (14.7% versus Western Australia state-wide average of 7.4%).

CONCLUSION

Adherence to oral glucose tolerance test screening in rural Western Australia is inadequate for effective screening for gestational diabetes mellitus. Screening was not acceptable or available for a significant proportion of women at risk. Efforts to improve oral glucose tolerance test adherence and exploration of alternative gestational diabetes mellitus screening strategies are required.

Gestational diabetes and adiposity are independent risk factors for perinatal outcomes: a population based cohort study in Sweden

AIMS

To evaluate the interaction effects of gestational diabetes (GDM) with obesity on perinatal outcomes.

METHODS

A population-based cohort study in Sweden excluding women without pre-gestational diabetes with a singleton birth between 1998 and 2012. Logistic regression was performed to evaluate the potential independent associations of GDM and BMI with adverse perinatal outcomes as well as their interactions. Main outcome measures were malformations, stillbirths, perinatal mortality, low Apgar score, fetal distress, prematurity and Erb's palsy.

RESULTS

Some 1,294,006 women were included, with a GDM prevalence of 1% (n = 14,833). The rate of overweight/obesity was 67.7% in the GDM-group and 36.1% in the non-GDM-group. No significant interaction existed. Offspring of women with GDM had significantly increased risk of malformations, adjusted odds ratio (aOR) 1.16 (95% confidence intervals 1.06-1.26), prematurity, aOR 1.86 (1.76-1. 98), low Apgar score, aOR 1.36 (1.10-1.70), fetal distress, aOR 1.09 (1.02-1.16) and Erb's palsy aOR 2.26 (1.79-2.86). No risk for stillbirth or perinatal mortality was seen. Offspring of overweight (BMI 25-29.9 kg/m² ), obese (BMI 30-34.9 kg/m² ) and severely obese women (BMI ≥ 35.0 kg/m² ) had significantly increased risks of all outcomes including stillbirth 1.51 (1.40-1.62) to 2.85 (2.52-3.22) and perinatal mortality 1.49 (1.40-1.59) to 2.83 (2.54-3.15).

CONCLUSIONS

There is no interaction effect between GDM and BMI for the studied outcomes. Higher BMI and GDM are major independent risk factors for most serious adverse perinatal outcomes. More effective pre-pregnancy and antenatal interventions are required to prevent serious adverse pregnancy outcomes among women with either GDM or high BMI.

Assessment of lactate production as a response to sustained intrapartum hypoxia in large-for-gestational-age newborns

INTRODUCTION

Lactate concentration in umbilical cord blood is an important measure of intrapartum anaerobic metabolism. The aim of the study was to compare lactate production of large-for-gestational-age (LGA) fetuses against appropriate-for-gestational-age (AGA) fetuses during hypoxia, in diabetic and non-diabetic mothers.

MATERIAL AND METHODS

A total of 17 358 validated paired arterial and venous umbilical cord blood samples taken at birth with a full panel of pH, glucose, and lactate were analyzed relative to LGA (n = 2789) and AGA (n = 14 569). Umbilical cord blood acidemia (pH < mean minus 2 SD) was identified in 518 cases.

RESULTS

Diabetes, but not acidemia, was more common among LGA (5.4%) than AGA cases (2.9%) (respectively P < .0001 and P < .69). At normal pH, glucose was lower in non-diabetes LGA cases, but not in diabetes LGA compared with corresponding AGA cases (respectively P < .0001 and P < .067). Glucose levels were higher in all groups during acidemia (P ≤ .0005), with lower values in non-diabetes LGA but not in diabetes LGA compared with corresponding AGA cases (respectively P = .005 and P < .58). At normal pH, lactate was lower in non-diabetes LGA but not in diabetes LGA compared with corresponding AGA cases (respectively P < .0001 and P < .98); during acidemia, lactate levels were higher in all groups (P < .0001), resulting in no significant difference between LGA and AGA in diabetes as well as in non-diabetes cases (respectively P = .29 and P < .084).

CONCLUSIONS

Considering cord acidemia a proxy for intrapartum hypoxia, LGA fetuses showed no impaired ability to produce lactate during hypoxia. Maternal diabetes did not hamper the ability of LGA fetuses to produce lactate during hypoxia.

Characteristics of different risk factors and fasting plasma glucose for identifying GDM when using IADPSG criteria: a cross-sectional study

Background

The Swedish National Board of Health and Welfare (SNBHW) recommended the new diagnostic criteria for GDM based upon Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study thresholds. Due to limited knowledge base, no recommendations were made on GDM screening. The aim of this study is to evaluate test characteristics of risk factors and fasting blood glucose as screening tests for diagnosing GDM using diagnostic thresholds based upon HAPO study 1.75/2.0 (model I/II respectively) odds ratio for adverse pregnancy outcomes.

Methods

This cross-sectional, population-based study included all pregnant women who attended maternal health care in Örebro County, Sweden between the years 1994–96. A 75 g OGTT with capillary fasting and 2-h blood glucose was offered to all pregnant women at week 28–32. Risk factors and repeated random glucose samples were collected. Sensitivity, specificity and predictive values of blood glucose were calculated.

Results

Prevalence of GDM was 11.7% with model I and 7.2% with the model II criteria. Risk factors showed 28%, (95% CI 24–32) and 31%, (95% CI 25–37) sensitivity for model I and II respectively. A fasting cut off ≥4.8 mmol/l occurred in 24% of women with 91%, (95% CI 88–94) sensitivity and 85%, (95% CI 83–86) specificity using model I while a fasting cut off ≥5.0 mmol/l occurred in 14% with 91%, (95% CI 87–94) sensitivity and 92%, (95% CI 91–93) specificity using model II.

Conclusion

Risk factor screening for GDM was found to be poorly predictive of GDM but fasting glucose of 4.8–5.0 mmol/l showed good test characteristics irrespective of diagnostic model and results in a low rate of OGTTs.

Neonatal delivery weight and risk of future maternal diabetes

OBJECTIVE

To investigate associations between neonatal delivery weight and future risk of maternal type 1 or type 2 diabetes.

METHODS

Data included in the Swedish Medical Birth Registry and Swedish National Diabetes Registry were merged to include all women born during 1930-1989; patients with pre-existing diabetes or gestational diabetes were excluded. Cox regression analyses were performed to identify associations between the neonatal delivery weight from the most recent pregnancy and later occurrence of diabetes.

RESULTS

There were 1 873 440 patients included in the analyses. An increased risk of type 1 (hazard ratio 3.60, 95% confidence interval [CI] 3.23-4.01) or type 2 diabetes (hazard ratio 2.77, 95% CI 2.68-2.87) was observed among patients who had a large for gestational age neonate compared with patients who had neonates within one standard definition of the mean weight for gestational age; the odds of developing type 1 (odds ratio 10.27, 95% CI 7.37-14.31) or type 2 diabetes (odds ratio 8.50, 95% CI 6.01-12.02) within 1 year of delivery was also increased compared with patients who had a neonate within one standard deviation of the mean weight for gestational age.

CONCLUSIONS

Delivering a large for gestational age neonate was a potent risk factor for the later development of maternal type 1 or type 2 diabetes.

Prevalence of gestational diabetes mellitus in Europe: A meta-analysis

AIMS

Estimates of the prevalence of gestational diabetes vary widely. It is important to have a clear understanding of the prevalence of this condition to be able to plan interventions and health care provision. This paper describes a meta-analysis of primary research data reporting the prevalence of gestational diabetes mellitus in the general pregnant population of developed countries in Europe.

METHODS

Four electronic databases were systematically searched in May 2016. English language articles reporting gestational diabetes mellitus prevalence using universal screening in general pregnant population samples from developed countries in Europe were included. All papers identified by the search were screened by one author, and then half screened independently by a second author and half by a third author. Data were extracted by one author. Values for the measures of interest were combined using a random effects model and analysis of the effects of moderator variables was carried out.

RESULTS

A total of 3258 abstracts were screened, with 40 studies included in the review. Overall prevalence of gestational diabetes mellitus was 5.4% (3.8-7.8). Maternal age, year of data collection, country, area of Europe, week of gestation at testing, and diagnostic criteria were found to have a significant univariate effect on GDM prevalence, and area, week of gestation at testing and year of data collection remained statistically significant in multivariate analysis. Quality category was significant in multivariate but not univariate analysis.

CONCLUSIONS

This meta-analysis shows prevalence of GDM that is at the upper end of previous estimates in Europe.

Overweight and obesity: a remaining problem in women treated for severe gestational diabetes

AIM

To analyse the impact of overweight and obesity on the risk of adverse maternal outcomes and fetal macrosomia in pregnancies of women treated for severe gestational diabetes.

METHODS

This was a population-based cohort study including all singleton pregnancies in Sweden without pre-existing diabetes in the period 1998-2012. Only mothers with an early- pregnancy BMI of ≥ 18.5 kg/m² were included. Logistic regression analysis was used to determine odds ratios with 95% CIs for maternal outcomes and fetal growth. Analyses were stratified by maternal gestational diabetes/non-gestational diabetes to investigate the impact of overweight/obesity in each group.

RESULTS

Of 1 249 908 singleton births, 13 057 were diagnosed with gestational diabetes (1.0%). Overweight/obesity had the same impact on the risks of caesarean section and fetal macrosomia in pregnancies with and without gestational diabetes, but the impact of maternal BMI on the risk of preeclampsia was less pronounced in women with gestational diabetes. Normal-weight women with gestational diabetes had an increased risk of caesarean section [odds ratio 1.26 (95% CI 1.16-1.37)], preeclampsia [odds ratio 2.03 (95% CI 1.71-2.41)] and large-for-gestational-age infants [odds ratio 2.25 (95% CI 2.06-2.46)]. Risks were similar in the overweight group without gestational diabetes, caesarean section [odds ratio 1.34 (1.33-1.36)], preeclampsia odds ratio [1.76 (95% CI 1.72-1.81)], large-for-gestational-age [odds ratio 1.76 (95% CI 1.74-1.79)].

CONCLUSIONS

Maternal overweight and obesity is associated with similar increments in risks of adverse maternal outcomes and delivery of large-for-gestational-age infants in women with and without gestational diabetes. Obese women with gestational diabetes are defined as a high-risk group. Normal-weight women with gestational diabetes have similar risks of adverse outcomes to overweight women without gestational diabetes.

Trends in diabetes in pregnancy in Sweden 1998-2012

OBJECTIVE

Diabetes in pregnancy has been shown to increase in parallel with the increasing prevalence of obesity. In this national population-based study, we analyzed the trends for gestational diabetes mellitus (GDM), type 1 diabetes in pregnancy, and type 2 diabetes in pregnancy in Sweden between 1998 and 2012.

RESEARCH DESIGN AND METHODS

A population-based cohort study using the Swedish national medical birth registry data. The time periods were categorized into 3-year intervals and adjusted for maternal body mass index (BMI), ethnicity, and age in a logistic regression.

RESULTS

Each type of diabetes increased over the studied 15-year period. Type 1 diabetes increased by 33.2% (22.2-45.3) and type 2 diabetes by 111% (62.2-174.4) in the adjusted model. Nordic women had the highest prevalence of type 1 diabetes (0·47%) compared with other ethnic groups. The increase in GDM and, to a lesser extent, type 2 diabetes was explained by country of birth, BMI, and maternal age. The prevalence of GDM in Nordic women (0.7-0.8%) did not increase significantly over the time period.

CONCLUSIONS

All types of diabetes in pregnancy increased over the 15-year time period in Sweden. Maternal pre-pregnancy BMI remains the key factor explaining the increase in GDM/type 2 diabetes. How to turn around the growing prevalence of diabetes in pregnancy, with its short-term and long-term health effects on both mother and child, requires population-based interventions that reduce the likelihood of entering pregnancy with a raised BMI.

Seasonal Pattern in the Diagnosis of Gestational Diabetes Mellitus in Southern Sweden

Aim. The aim of this study was to examine seasonal patterns in glucose tolerance and in the diagnosis of gestational diabetes mellitus (GDM). Methods. Altogether, 11 538 women underwent a 75-g oral glucose tolerance test (OGTT) in the twenty-eighth week of pregnancy during the years 2003-2005 in southern Sweden. GDM was defined by the 2-h capillary glucose concentration in the OGTT (≥8.9 mmol/L). Chi-squared test, analysis of variance, and regression analyses were used for statistical evaluations. Results. The seasonal frequency of GDM ranged from 3.3% in spring to 5.5% in summer (p < 0.0001). Mean 2-h glucose concentrations followed the same seasonal trend, with a difference of 0.15 mmol/L between winter and summer (p < 0.0001). The 2-h glucose level increased by 0.009 mmol/L for every degree increase in temperature (p < 0.0001). In regression analysis, summer (June-August) was associated with increased 2-h glucose level (p < 0.001) and increased frequency of GDM compared to the other seasons (odds ratio 1.51, 95% confidence interval 1.24-1.83, and p < 0.001). Conclusions. Our findings suggest seasonal variation in the 2-h glucose concentration in the OGTT and in the proportion of women diagnosed with GDM, with a peak in the summer.

The relative importance of maternal body mass index and glucose levels for prediction of large-for-gestational-age births

Background

The risk of gestational diabetes mellitus (GDM) increases substantially with increasing maternal body mass index (BMI). The aim of the present study was to evaluate the relative importance of maternal BMI and glucose levels in prediction of large-for-gestational-age (LGA) births.

Method

This observational cohort study was based on women giving birth in southern Sweden during the years 2003–2005. Information on 10 974 pregnancies was retrieved from a population-based perinatal register. A 75-g oral glucose tolerance test (OGTT) was performed in the 28 week of pregnancy for determination of the 2-h plasma glucose concentration. BMI was obtained during the first trimester. The dataset was divided into a development set and a validation set. Using the development set, multiple logistic regression analysis was used to identify maternal characteristics associated with LGA. The prediction of LGA was assessed by receiver-operating characteristic (ROC) curves, with LGA defined as birth weight > +2 standard deviations of the mean.

Results

In the final multivariable model including BMI, 2-h glucose level and maternal demographics, the factor most strongly associated with LGA was BMI (odds ratio 1.1, 95 % confidence interval [CI] 1.08–1.30). Based on the total dataset, the area under the ROC curve (AUC) of 2-h glucose level to predict LGA was 0.54 (95 % CI 0.48–0.60), indicating poor performance. Using the validation database, the AUC for the final multiple model was 0.69 (95 % CI 0.66–0.72), which was identical to the AUC retrieved from a model not including 2-h glucose (0.69, 95 % CI 0.66–0.72), and larger than from a model including 2-h glucose but not BMI (0.63, 95 % CI 0.60–0.67).

Conclusions

Both the 2-h glucose level of the OGTT and maternal BMI had a significant effect on the risk of LGA births, but the relative contribution was higher for BMI. The findings highlight the importance of concentrating on healthy body weight in pregnant women and closer monitoring of weight during pregnancy as a strategy for reducing the risk of excessive fetal growth.

The Risk of Gestational Diabetes Mellitus Following Bereavement: A Cohort Study from Denmark and Sweden

BACKGROUND

We investigated whether bereavement of a close family member - a source of severe psychological stress exposure - the year before pregnancy is associated with gestational diabetes mellitus (GDM).

METHODS

We studied pregnant women with livebirths in Denmark during 1994-2008 and with births in Sweden during 1987-2006 (n = 2,569,446). We obtained data on death of women's parents, siblings, and older children, and on demographic and health- and pregnancy-related factors through linkage between nationwide registers.

RESULTS

In multivariable models, death of a close relative the year before pregnancy was associated with a 14% increased odds of GDM [95% confidence intervals (CIs) 1.03, 1.26]. The odds ratios corresponding to the loss of a child, parent, and sibling were 1.51 (95% CI: 1.17, 1.95), 1.12 (95% CI: 1.00, 1.25), and 0.68 (95% CI: 0.40, 1.25), respectively. Deaths due to cardiovascular diseases or diabetes were more closely related to the risk of GDM than other types of deaths. We found no association between unnatural deaths and the risk of GDM.

CONCLUSIONS

Death of a close relative the year before pregnancy was associated with a modestly increased GDM risk. Our findings according to the relative's cause of death suggest that differences in screening for GDM among exposure groups and residual confounding by familial factors related to metabolic and cardiovascular diseases may have contributed to this association. If there is a causal stress effect on GDM in this predominantly Nordic population, it is most likely small.

Perinatal outcome in relation to fetal sex in offspring to mothers with pre-gestational and gestational diabetes--a population-based study

AIM

The objective of the present study was to investigate if perinatal outcome differs with fetal sex in pregnancies with maternal Type 1 diabetes, Type 2 diabetes or gestational diabetes.

METHODS

This was a population-based cohort study, with data from the Medical Birth Registry in Sweden throughout the period 1998-2007. Singleton pregnancies with maternal Type 1 diabetes (n = 4092), Type 2 diabetes (n = 412) and gestational diabetes (n = 8602) were identified based on the International Classification of Diseases, 10th edition code. For comparison, 905 565 pregnancies without diabetes were included. The primary outcome was a composite outcome, consisting of any of the following diagnoses: perinatal mortality rate, major malformation, preterm delivery, acute respiratory disorders and neonatal hypoglycaemia. Logistic regression was used to obtain odds ratios for adverse outcomes in male offspring within the diabetic and reference cohorts, respectively.

RESULTS

In pregnancies with diabetes, maternal characteristics did not differ with fetal sex, except for a higher rate of Caesarean delivery in male offspring of women with Type 1 diabetes. Male infants to mothers with Type 1 diabetes and gestational diabetes had significantly increased odds of respiratory disorders [adjusted odds ratio (confidence interval) Type 1 diabetes: 1.50 (1.12-2.02); gestational diabetes: 1.81 (1.27-2.57)]. Male infants to mothers with gestational diabetes also had significantly increased odds of major malformations [adjusted odds ratio: 1.44 (1.07-1.93)]. In offspring of mothers with Type 2 diabetes, odds ratios of most outcomes were higher in male infants; however, not significantly different from female infants. In pregnancies without diabetes, male infants had significantly higher odds of all adverse outcomes, except perinatal mortality rate.

CONCLUSION

The risk of adverse perinatal outcome in offspring of mothers with Type 1 diabetes and gestational diabetes did not differ by sex, except for a higher risk in male infants for respiratory disorders. The risk of major malformations was also significantly increased in male offspring to mothers with gestational diabetes. In offspring of mothers with Type 2 diabetes, no significant differences between sexes were found.

Gestational diabetes mellitus and later cardiovascular disease: a Swedish population based case-control study

Objective

To identify if gestational diabetes mellitus (GDM) is a clinically useful marker of future cardiovascular disease (CVD) risk and if GDM combined with other risks (smoking, hypertension or body mass) identifies high-risk groups.

Design

Population-based matched case–control study.

Setting

National Swedish register data from 1991 to 2008.

Population

A total of 2639 women with a cardiovascular event and matched controls.

Methods

Conditional logistic regression examined associations with CVD before and after adjustment for conventional risk factors and confounders. Effect modification for the association of GDM with CVD by body mass index (BMI), smoking and chronic hypertension was assessed by stratification and interaction testing. Adjustment for diabetes post-pregnancy evaluated its mediating role.

Main outcome measures

Inpatient diagnoses or causes of death identifying ischemic heart disease, ischemic stroke, atherosclerosis or peripheral vascular disease.

Results

The adjusted odds ratios (and 95% confidence intervals) for the association of CVD with GDM are 1.51 (1.07–2.14), 2.23 (2.01–2.48) for smoking, 1.98 (1.71–2.29) for obesity and 5.10 (3.18–8.18) for chronic hypertension. In stratified analysis the association of CVD with GDM was only seen among women with BMI ≥25, with an odds ratio of 2.39 (1.39–4.10), but only women with a BMI <30 accounted for this increased risk. Adjustment for post-pregnancy diabetes attenuated it somewhat to 1.99 (1.13–3.52).

Conclusions

In the absence of other recognised cardiovascular risk factors, such as smoking, obesity or chronic hypertension, GDM is a useful marker of raised CVD risk among women with BMI between 25 and 29.

Disproportionate body composition and neonatal outcome in offspring of mothers with and without gestational diabetes mellitus

OBJECTIVE

High birth weight is a risk factor for neonatal complications. It is not known if the risk differs with body proportionality. The primary aim of this study was to determine the risk of adverse pregnancy outcome in relation to body proportionality in large-for-gestational-age (LGA) infants stratified by maternal gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

Population-based study of all LGA (birth weight [BW] >90th percentile) infants born to women with GDM (n = 1,547) in 1998-2007. The reference group comprised LGA infants (n = 83,493) born to mothers without diabetes. Data were obtained from the Swedish Birth Registry. Infants were categorized as proportionate (P-LGA) if ponderal index (PI) (BW in grams/length in cm(3)) was ≤90th percentile and as disproportionate (D-LGA) if PI >90th percentile. The primary outcome was a composite morbidity: Apgar score 0-3 at 5 min, birth trauma, respiratory disorders, hypoglycemia, or hyperbilirubinemia. Logistic regression analysis was used to obtain odds ratios (ORs) for adverse outcomes.

RESULTS

The risk of composite neonatal morbidity was increased in GDM pregnancies versus control subjects but comparable between P- and D-LGA in both groups. D-LGA infants born to mothers without diabetes had significantly increased risk of birth trauma (OR 1.19 [95% CI 1.09-1.30]) and hypoglycemia (1.23 [1.11-1.37]). D-LGA infants in both groups had significantly increased odds of Cesarean section.

CONCLUSIONS

The risk of composite neonatal morbidity is significantly increased in GDM offspring. In pregnancies both with and without GDM, the risk of composite neonatal morbidity is comparable between P- and D-LGA.

The potential impact of new diagnostic criteria on the frequency of gestational diabetes mellitus in Sweden

The International Association of Diabetes and Pregnancy Study Groups (IADPSG) has suggested new diagnostic criteria for gestational diabetes mellitus. Many centers in Europe still use the World Health Organization (WHO) criteria. In southern Sweden we use the 2-h threshold of the European Association for the Study of Diabetes criteria based on universal screening with a 75-g oral glucose tolerance test. We have retrospectively scrutinized oral glucose tolerance tests in a subset of 174 women included in a previous study, diagnosed with gestational diabetes mellitus 1996-1999. A complete repeat oral glucose tolerance test was performed directly after diagnosis in 120 women. When applying the current Swedish criteria, and the IADPSG and the WHO criteria to the material, gestational diabetes mellitus was confirmed in 67% (80/120), 84% (101/120), and 80% (96/120), respectively. Hence, 26% (101/80) more women were identified by the IADPSG criteria and 20% (96/80) more women by the WHO criteria, compared with the criteria presently in use.

Gestational diabetes mellitus: including serum pregnancy-associated plasma protein-A testing in the clinical management of primiparous women? A case-control study

AIMS

To assess pregnancy-associated plasma protein A (PAPP-A) correlation with GDM and its usefulness in predicting GDM in primiparous women.

METHODS

First trimester data related to 307 pregnant women affected by GDM and 366 control pregnant women were retrieved from a computer data base and integrated with ad hoc data. Clinical data were recorded at delivery. A logistic model was used to analyze the association between first trimester data and subsequent clinical outcomes. We derived a risk score using both classical risk factors for GDM and PAPP-A.

RESULTS

Diabetic and control women were significantly different in terms of age (p<0.001), BMI (p<0.001), weight (p<0.001), family history of diabetes (p<0.001), PAPP-A concentration and PAPP-A corrected multiple of the median (MoM) (p<0.001). The ROC-AUC of the clinical risk score was 0.60 (95%CI 0.56-0.64), the adjusted score including PAPP-A MoM was 0.70 (95%CI 0.66-0.74).

CONCLUSIONS

Low PAPP-A was strongly associated with GDM and lower values were found in diabetic women needing insulin therapy. Adding PAPP-A to first trimester screening could improve the prediction of women at high risk who will develop GDM. Further studies are needed to validate the applicability of our findings in different populations and settings.

Gestational diabetes and preeclampsia in association with air pollution at levels below current air quality guidelines

BACKGROUND

Several studies have estimated associations between air pollution and birth outcomes, but few have evaluated potential effects on pregnancy complications.

OBJECTIVE

We investigated whether low-level exposure to air pollution is associated with gestational diabetes and preeclampsia.

METHODS

High-quality registry information on 81,110 singleton pregnancy outcomes in southern Sweden during 1999-2005 was linked to individual-level exposure estimates with high spatial resolution. Modeled exposure to nitrogen oxides (NOx), expressed as mean concentrations per trimester, and proximity to roads of different traffic densities were used as proxy indicators of exposure to combustion-related air pollution. The data were analyzed by logistic regression, with and without adjusting for potential confounders.

RESULTS

The prevalence of gestational diabetes increased with each NOx quartile, with an adjusted odds ratio (OR) of 1.69 (95% CI: 1.41, 2.03) for the highest (> 22.7 µg/m3) compared with the lowest quartile (2.5-8.9 µg/m3) of exposure during the second trimester. The adjusted OR for acquiring preeclampsia after exposure during the third trimester was 1.51 (1.32, 1.73) in the highest quartile of NOx compared with the lowest. Both outcomes were associated with high traffic density, but ORs were significant for gestational diabetes only.

CONCLUSION

NOx exposure during pregnancy was associated with gestational diabetes and preeclampsia in an area with air pollution levels below current air quality guidelines.

Use of healthcare resources after gestational diabetes mellitus: a longitudinal case-control analysis

AIMS

To analyse whether gestational diabetes mellitus (GDM) was associated with increases in healthcare utilisation after delivery.

METHODS

A longitudinal case-control registry-based study of 579 women with GDM delivered in 1995-2001. Two controls for each case were selected from the Swedish National Board of Health and Welfare, matched for year of birth, year of delivery, and municipality of residence. Data regarding healthcare utilisation was provided by the Patients' Administrative System in Skåne County, Sweden, covering the period from the years of delivery up to year 2009.

RESULTS

Women with previous GDM had higher mean number of contacts and total cost in the years after delivery as compared to controls, also when excluding utilisation related to subsequent pregnancies and childbirth. By year 2009, 31% of women with prior GDM were diagnosed with diabetes, compared to 1% of controls. Women diagnosed with diabetes were more likely to use health care (odds ratio 14.22, 95% confidence interval 5.87-34.45) controlling for age and time since delivery, whereas cases not diagnosed with diabetes did not differ from controls. The average annual cost of healthcare utilisation was 101% higher (p<0.001) for women with diabetes 10 years after delivery compared to controls.

CONCLUSIONS

GDM was associated with higher healthcare utilisation postpartum for women who had a diabetes diagnosis. The results call for implementation of structured programmes to follow up women with GDM postpartum for early detection of diabetes and effective management, which may have the potential for improved health and savings in healthcare costs.

Outcomes of gestational diabetes in Sweden depending on country of birth

OBJECTIVE

To analyze maternal and neonatal outcomes for women with gestational diabetes mellitus (GDM) in Sweden, depending on country of birth (Nordic vs. non-Nordic women).

DESIGN

Population-based cohort study using the Swedish Medical Birth register.

SETTING

Data on pregnant women in Sweden with diagnosed GDM.

POPULATION

All singleton births to women with GDM between 1998 and 2007 (n = 8560).

METHODS

Logistic regression in an adjusted model to assess the risk of adverse maternal and neonatal outcomes. Chi-squared tests or Student's unpaired t-tests were used to analyze differences between maternal and fetal characteristics.

MAIN OUTCOME MEASURES

Maternal and neonatal complications.

RESULTS

GDM incidence was higher at 2.0% among non-Nordic women, compared with 0.7% in the Nordic group. The non-Nordic women were older, had less chronic hypertensive disease, smoked less, and had lower BMI and shorter height. Preeclampsia was significantly lower in the non-Nordic group. The mean birthweight (3561 vs. 3698 g, p < 0.001) and the large-for-gestational age rate (11.7 vs. 17.5%, p < 0.001) were significantly lower in the non-Nordic group. Large-for-gestational age was dependent on maternal height [crude odds ratio 0.6 (0.5-0.7) and adjusted odds ratio 0.8 (0.6-0.9)].

CONCLUSIONS

Non-Nordic women with GDM in Sweden have better obstetrical and neonatal outcomes than Nordic women. These results do not support the idea of inequality of health care. Large-for-gestational age as a diagnosis is highly dependent on maternal height, which raises the question of the need for individualized growth curves.

Genetic prediction of postpartum diabetes in women with gestational diabetes mellitus

AIMS

To examine whether genetic variants that predispose individuals to type 2 diabetes (T2D) could predict the development of diabetes after gestational diabetes mellitus (GDM).

METHODS

13 SNPs (FTO rs8050136, CDKAL1 rs7754840 and rs7756992, CDKN2A/2B rs10811661, HHEX rs1111875, IGF2BP2 rs1470579 and rs4402960, SLC30A8 rs13266634, TCF7L2 rs7903146, PPARG rs1801282, GCK rs1799884, HNF1A rs1169288, and KCNJ11 rs5219) were genotyped in 793 women with GDM after a median follow-up of 57 months.

RESULTS

After adjustment for age and ethnicity, the TCF7L2 rs7903146 and the FTO rs8050136 variants significantly predicted postpartum diabetes; hazard ratio (95% confidence interval 1.29 (1.01-1.66) and 1.36 (1.06-1.74), respectively (additive model) versus 1.45 (1.01-2.08) and 1.56 (1.06-2.29) (dominant model)). Adjusting for BMI attenuated the effect of the FTO variant, suggesting that the effect was mediated through its effect on BMI. Combining all risk alleles to a weighted risk score was significantly associated with the risk of postpartum diabetes (hazard ratio 1.11, 95% confidence interval 1.05-1.18, p=0.00016 after adjustment for age and ethnicity).

CONCLUSIONS

The TCF7L2 rs7903146 and FTO rs8050136 polymorphisms, and particularly a weighted risk score of T2D risk alleles, predict diabetes after GDM. Further studies in other populations are needed to confirm our results.

Gestational diabetes mellitus in Europe: prevalence, current screening practice and barriers to screening. A review

BACKGROUND

Gestational diabetes mellitus is a potentially serious condition that affects many pregnancies and its prevalence is increasing. Evidence suggests early detection and treatment improves outcomes, but this is hampered by continued disagreement and inconsistency regarding many aspects of its diagnosis.

METHODS

The Vitamin D and Lifestyle Intervention for Gestational Diabetes Mellitus Prevention (DALI) research programme aims to promote pan-European standards in the detection and diagnosis of gestational diabetes and to develop effective preventive interventions. To provide an overview of the context within which the programme will be conducted and its findings interpreted, systematic searching and narrative synthesis have been used to identify and review the best available European evidence relating to the prevalence of gestational diabetes, current screening practices and barriers to screening.

RESULTS

Prevalence is most often reported as 2-6% of pregnancies. Prevalence may be lower towards the Northern Atlantic seaboard of Europe and higher in the Southern Mediterranean seaboard. Screening practice and policy is inconsistent across Europe, hampered by lack of consensus on testing methods, diagnostic glycaemic thresholds and the value of routine screening. Poor clinician awareness of gestational diabetes, its diagnosis and local clinical guidelines further undermine detection of gestational diabetes.

CONCLUSIONS

Europe-wide agreement on screening approaches and diagnostic standards for gestational diabetes could lead to better detection and treatment, improved outcomes for women and children and a strengthened evidence base. There is an urgent need for well-designed research that can inform decisions on best practice in gestational diabetes mellitus screening and diagnosis.

Prevalence of impaired glucose tolerance and diabetes after gestational diabetes mellitus comparing different cut-off criteria for abnormal glucose tolerance during pregnancy

OBJECTIVE

To determine the prevalence of diabetes and impaired glucose tolerance after gestational diabetes mellitus in relation to different categories of glucose tolerance during pregnancy.

DESIGN

Prospective study.

SETTING

Four delivery departments and three hospitals in southern Sweden took part in recruitment and follow-up.

POPULATION

Women undergoing a 75g oral glucose tolerance test during pregnancy delivering in 2003-2005.

METHODS

At first follow-up, one to two years after delivery, 29% of eligible women with abnormal glucose tolerance during pregnancy had an oral glucose tolerance test - 160 with gestational diabetes and 309 with gestational impaired glucose tolerance - in addition to 167 control women. Cut-off levels defining gestational diabetes and impaired glucose tolerance were two-hour capillary blood glucose levels of 9.0 and 7.8mmol/l or plasma glucose 10.0 and 8.6mmol/l, respectively.

MAIN OUTCOME MEASURES

Frequency of abnormal test results at follow-up.

RESULTS

Diabetes was diagnosed in 11% and impaired glucose tolerance in 24% of women with gestational diabetes vs. 4 and 23% in those with gestational impaired glucose tolerance, respectively. Combining women with abnormal test results during pregnancy revealed diabetes or impaired glucose tolerance in 29% as compared to 10% among controls; the odds ratio (95% confidence interval) for having abnormal test results was 3.3 (1.8-5.9) in a multivariate logistic regression analysis.

CONCLUSIONS

Lowering the cut-off level for gestational diabetes to include the category of impaired glucose tolerance would identify a high percentage of women with diabetes and impaired glucose tolerance postpartum, who constitute target groups for intervention and/or diabetes prevention.

Screening for hyperglycaemia in pregnancy: Consensus and controversy

Policy decisions on whether to implement screening programmes depend on whether the proposed programmes meet a set of criteria laid down by the World Health Organization. Screening for hyperglycaemia in pregnancy (HGP) does not meet all the criteria. However the case for screening has been strengthened by a number of recent developments, including: rising prevalence of HGP because of increasing maternal age and BMI; the results of the Hyperglycaemia and Adverse Pregnancy Outcomes study, showing that adverse effects of HGP are seen over a wider range of plasma glucose levels than previously thought; two large trials which showed the benefits of treating lesser degrees of HGP; trials showing that metformin and glibenclamide were effective and safe alternatives to immediate insulin in those without good control on lifestyle measures alone. However uncertainties remain around the threshold for treatment, and on the best screening strategy.

Maternal and neonatal outcomes and time trends of gestational diabetes mellitus in Sweden from 1991 to 2003

AIMS

To determine maternal and neonatal outcomes for women with gestational diabetes mellitus (GDM) in Sweden during 1991-2003, and to compare the outcomes in the two time periods.

METHODS

This is a population-based cohort study using the Swedish Medical Birth Register data for the period 1991-2003. There were 1,260,297 women with singleton pregnancies registered during this time, of whom 10 525 were diagnosed with GDM, based on a 75 g oral glucose tolerance test. The main diagnostic criteria were fasting capillary whole blood glucose>or=6.1 mmol/l and 2 h blood glucose>or=9.0 mmol/l.

RESULTS

Maternal characteristics differed significantly between the GDM and non-GDM group. Adjusted odds ratios (OR) were as follows: for pre-eclampsia, 1.81 (95% confidence interval (CI) 1.64-2.00); for shoulder dystocia, 2.74 (2.04-3.68); and for Caesarean section, 1.46 (1.38-1.54). No difference was seen in perinatal mortality, stillbirth rates, Apgar scores, fetal distress or transient tachypnoea. There was a markedly higher risk of large for gestational age, OR 3.43 (3.21-3.67), and Erb's palsy, OR 2.56 (1.96-3.32), in the GDM group, and statistically significant differences in prematurity<37 weeks, birth weight>4.5 kg, and major malformation, OR 1.19-1.71. No statistically significant improvement in outcomes was seen between the two study periods.

CONCLUSIONS

Women with GDM have higher risks of pre-eclampsia, shoulder dystocia and Caesarean section. Their infants are often large for gestational age and have higher risks of prematurity, Erb's palsy and major malformations. These outcomes did not improve over time.

Prediction of postpartum diabetes in women with gestational diabetes mellitus

AIMS/HYPOTHESIS

We studied the incidence of postpartum diabetes after gestational diabetes mellitus and investigated biochemical and clinical predictors of postpartum diabetes.

METHODS

We monitored 174 women with gestational diabetes by performing oral glucose tolerance tests during pregnancy as well as 1, 2 and 5 years postpartum. Women who developed impaired fasting glucose, impaired glucose tolerance or diabetes were compared with women who remained normoglycaemic at 5 years. Insulinogenic index, disposition index and HOMA-beta cell index were used to assess beta cell function; insulin resistance was estimated by HOMA index of insulin resistance.

RESULTS

At 5 years postpartum, 30% of the women had developed diabetes and 51% some form of abnormal glucose tolerance. Women who developed diabetes had higher fasting glucose and HbA(1c) during pregnancy than those who remained normoglycaemic. They also had lower HOMA-beta cell index, insulinogenic index and disposition index than the normoglycaemic women. HbA(1c) and fasting glucose during pregnancy as well as the number of previous pregnancies and family history of diabetes were independent predictors of postpartum diabetes. HbA(1c) > or =4.7% (Swedish Mono S) or > or =5.7% (National Glycohemoglobin Standardization Program) and fasting blood glucose > or =5.2 mmol/l were associated with a four- to sixfold increased risk.

CONCLUSIONS/INTERPRETATION

Among women with gestational diabetes mellitus, those at risk of future diabetes can be identified by HbA(1c) and fasting glucose values in the upper normal range during pregnancy. A family history of diabetes and previous pregnancies further increase this risk.

Surprisingly low compliance to local guidelines for risk factor based screening for gestational diabetes mellitus - A population-based study

Background

Screening for gestational diabetes mellitus (GDM) is routine during pregnancy in many countries in the world. The screening programs are either based on general screening offered to all pregnant women or risk factor based screening stipulated in local clinical guidelines. The aims of this study were to investigate: 1) the compliance with local guidelines of screening for GDM and 2) the outcomes of pregnancy and birth in relation to risk factors of GDM and whether or not exposed to oral glucose tolerance test (OGTT).

Methods

This study design was a population-based retrospective cross-sectional study of 822 women. A combination of questionnaire data and data collected from medical records was applied. Compliance to the local guidelines of risk factor based screening for GDM was examined and a comparison of outcomes of pregnancy and delivery in relation to risk factor groups for GDM was performed.

Results

Of the 822 participants, 257 (31.3%) women fulfilled at least one criterion for being exposed to screening for GDM according to the local clinical guidelines. However, only 79 (30.7%) of these women were actually exposed to OGTT and of those correctly exposed for screening, seven women were diagnosed with GDM. Women developing risk factors for GDM during pregnancy had a substantially increased risk of giving birth to an infant with macrosomia.

Conclusion

Surprisingly low compliance with the local clinical guidelines for screening for GDM during pregnancy was found. Furthermore, the prevalence of the risk factors of GDM in our study was almost doubled compared to previous Swedish studies. Pregnant women developing risk factors of GDM during pregnancy were found to be at substantially increased risk of giving birth to an infant with macrosomia. There is a need of actions improving compliance to the local guidelines.

Diabetes and pregnancy: women's opinions about the care provided during the childbearing year

BACKGROUND

The extended programmes for pregnant women with diabetes, needed to improve pregnancy outcome, might negatively influence the experience of expecting a baby.

AIM

To investigate opinions about care during pregnancy, childbirth and the postnatal period among women with diabetes mellitus (DM) and gestational DM (GDM).

METHOD

A four-part questionnaire was constructed, covering the childbearing year, with a focus on treatment and information. A total of 156 women were asked to participate (53 DM, 103 GDM), three refused. The questionnaire was anonymous.

RESULTS

The reply frequency was 94%. Of all answers, 95% fell in neutral-satisfied range (Lickert scale 2-5). Three answering patterns deviated positively (care on Specialist Antenatal Clinic, accessibility, and participation-responsibility-respect). Four patterns deviated negatively (information flow, preparation, postpartum care and postpartum check-up). Increased supervision caused problems with time for the family and at work. Comments showed focus on diabetes, forcing the healthy pregnancy aspects into the background. The answers concerning treatment indicated satisfaction (4 + 5 Lickert scale). Women with GDM felt badly prepared before the glucose tolerance test. It was doubtful whether they had been able to make an informed choice about participating. Lack of knowledge among staff was pointed out. Need for more written material was expressed.

CONCLUSION

Satisfaction with care was shown. A discussion about the implication of informed choice with both staff and mothers are needed. Sharper implementation of the diabetes-care-chain was also an area for improvement.