Are the WHO (1980) criteria for the 75 g oral glucose tolerance test appropriate for pregnant women?

Consensus in Gestational Diabetes MELLITUS: Looking for the Holy Grail

The world's pre-eminent diabetes, obstetric, endocrine, and health organizations advocate a plethora of diverse algorithms for the screening, diagnosis, management, and follow-up of gestational diabetes mellitus (GDM). Additionally, there are regional recommendations of local health societies. Several of these proposals for GDM are contentious because some of them were developed from unscientific studies, based on expert-opinion, catered to preserve resources, and subjectively modified for convenience. Due to the wide variety of choices available, the approach to GDM can be extremely diverse even within the same hospital. This lack of consensus creates major problems in addressing prevalence, complications, efficacy of treatment, and follow-up of GDM. Moreover, it becomes nearly impossible to compare the numerous studies. Furthermore, the lack of consensus confuses the health care providers of obstetric health who look to the experts for guidance. Therefore, a clear, objective, "evidence-based" global approach, which is simple, easy to follow, and validated by corroborative research, is crucial. We contend that, despite decades of research, a single acceptable global guideline is not yet on the horizon.

Is Risk Factor-based Screening Good Enough to Detect Gestational Diabetes Mellitus in High-Risk Pregnant Women? A Sri Lankan Experience

Background:

There is a long lasting dilemma over the ideal screening and diagnostic method in gestational diabetes mellitus (GDM). Even though universal screening is commonly practiced, selective screening based on risk factors is also practiced in some center. The aim of this study is to evaluate the most appropriate method to screen GDM in high-risk pregnant women in Sri Lanka.

Methods:

This study was a clinic-based, cross-sectional study conducted in a tertiary referral center, Sri Lanka. All women underwent 75 g oral glucose tolerance test at 24–28 weeks of gestation. Diagnosis of GDM was made according to the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) and World Health Organization (WHO) criteria.

Results:

With universal screening using IADPSG criteria, 23.2% (105/452) were found to have GDM and with risk factor-based screening 20.1% (91/452) were detected to have GDM. The prevalence of GDM dropped to 18.1% when GDM was diagnosed using the WHO criteria with universal screening approach. It was further dropped to 15.7% when the WHO criteria were used along with risk factors-based screening approach.

Conclusions:

The IADPSG criteria labeled considerably higher number of women as having GDM compared to the WHO criteria. With regards to the screening methods, the risk-based screening had a lower detection rate of GDM; however, it reduced the necessity of screening of women by around 20%.

Are There Benefits for Gestational Diabetes Mellitus in Treating Lower Levels of Hyperglycemia Than Standard Recommendations?

OBJECTIVES

The new International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommendations for diagnosis of gestational diabetes mellitus (GDM) are generating discussion regarding their universal adoption. Our centre is currently using stricter GDM diagnostic criteria than those proposed by the IADPSG. Evaluation of complication rates and their predictors in our cohort may provide insight for the care of this high-risk population. Therefore, we determined complication rates and identified antepartum maternal predictors of adverse outcomes in our cohort with mild GDM.

METHODS

A retrospective cohort study was performed between 2005 and 2011. It included women with and without GDM, which was diagnosed if fasting plasma glucose levels were 5.0 or above or 2-hour post 75 gram oral glucose tolerance test (OGTT) were 7.8 mmol/L or higher.

RESULTS

A total of 3712 women, with and without diabetes, were included. Rates of macrosomia and pre-eclampsia were significantly higher in the group with GDM but were lower than the rates usually reported. Macrosomia, the need for insulin therapy or caesarean section and postpartum glucose intolerance predictors included prepregnancy body mass index, excessive gestational weight gain and OGTT screening results, although no specific threshold was found.

CONCLUSIONS

This study provides insight into GDM-related complications rates and the benefits of intervention in a large cohort of women with levels of hyperglycemia lower than those currently recommended for diagnosis of GDM. These findings suggest a continuous association between adverse outcomes and maternal hyperglycemia and highlight the important role of maternal risk factors other than glycemic results in the development of pregnancy-related complications. Milder forms of hyperglycemia that would not be identified by IADPSG guidelines may benefit from treatment.

Comparative analysis of current diagnostic criteria for gestational diabetes mellitus

BACKGROUND

To compare current guidelines for diagnosis of gestational diabetes mellitus (GDM) and to identify the ones that are the most relevant for application among pregnant Bulgarian population.

METHODS

A total of 800 pregnant women at high risk for GDM underwent 75 g oral glucose tolerance test between 24 and 28 weeks of gestation as antenatal screening. The results were interpreted and classified according to the guidelines of the International Association of Diabetes and Pregnancy Study Groups (IADPSG), American Diabetes Association (ADA), Australasian Diabetes in Pregnancy Society, Canadian Diabetes Association, European Association for the Study of Diabetes, New Zealand Society for the study of Diabetes and World Health Organization.

RESULTS

The application of different diagnostic criteria resulted in prevalences of GDM between 10.8% and 31.6%. Using any two sets of criteria, women who were classified differently varied between 0.1% and 21.1% (P < 0.001).The IADPSG criteria were the most inclusive criteria and resulted in the highest prevalence of GDM. There was a significant difference in the major metabolic parameters between GDM and control groups, regardless of which of the diagnostic criteria applied. GDM diagnosed according to all criteria resulted in increased proportion of delivery by caesarean section (CS). However, only ADA and IADPSG criteria identified both increased macrosomia (odds ratio, 2.36; 2.29) and CS rate.

CONCLUSION

The need for GDM screening is indisputable. In our view, the new IADPSG guidelines offer a unique opportunity for a unified national and global approach to GDM.

Specific information about the WHO guidelines for gestational diabetes screening improves clinical practices

RATIONALE, AIMS AND OBJECTIVE

To evaluate the impact of specific information on World Health Organization (WHO) guidelines for gestational diabetes mellitus (GDM) screening on clinical practices and to estimate its acceptance by women.

METHODS

A non-randomized interventional study, comparing two periods, that is, before (period I) and after (period II) the implementation of the WHO guidelines during year 2000 in three obstetrical units, using reminders, meetings and pre-printed prescription sheets. Women were interviewed on GDM screening acceptance.

RESULTS

A total of 333 pregnant women were included in period I and 345 in period II. The proportion of women who were screened significantly increased between period I and period II (0.9% in period I, 59.1% in period II, P < 10(-3)). The screening test was realized in accordance with guidelines for 80% of women in period II. The acceptability of the test by women was estimated at 98%. Furthermore, 90% of them would accept to be screened again during another pregnancy.

DISCUSSION

Specific information about WHO screening guidelines improves doctor practices. Moreover, the high rate of acceptance by women is an argument to promote more widespread WHO screening for GDM during pregnancy.

Gestational diabetes: dilemma caused by multiple international diagnostic criteria

AIMS

To highlight the variation in the diagnosis of gestational diabetes (GDM) as defined by six well-accepted international expert panels.

METHODS

Two thousand, five hundred and fifty-four pregnant women underwent a 75-g oral glucose tolerance test for routine, antenatal GDM screening. They were classified using the criteria of the American Diabetes Association, Australasian Diabetes in Pregnancy Society, the Canadian Diabetes Association, the European Association for the Study of Diabetes, the New Zealand Society for the study of Diabetes and the World Health Organization (WHO).

RESULTS

Between any two criteria, both the GDM prevalence (range; 7.9-24.9%) and the women classified differently [range; 70 (2.7%)-454 (17.8%) women], was significant (P<0.001). The most inclusive criteria, i.e. Australasian, despite generating the highest prevalence of GDM, did not pick up all the women identified by the most restrictive criteria, i.e. Canadian. The Australasian and the WHO criteria were associated with an increase in the number of Caesarean sections [odds ratio (OR); 1.64, 1.45, respectively] while the American, Canadian and New Zealand criteria identified an increase in macrosomia (birthweight>or=4000 g) incidence (OR; 2.09, 2.01, 1.92, respectively).

CONCLUSIONS

The guidelines of the various professional committees, being based on consensus and expert opinion, show major discrepancies in their ability to identify women with GDM and their capacity to predict adverse pregnancy outcome. Only evidence-based criteria derived from reliable and consistent scientific data will eliminate the confusion caused in clinical practice.

A comparison between a 75-g and 100-g oral glucose tolerance test in pregnant women

OBJECTIVES

To test the validity of a 75-g, 2-h oral glucose tolerance test (OGTT) for diagnosing gestational diabetes mellitus (GDM) using the criteria and reference values suggested by the American Diabetes Association for the 100-g, 3-h OGTT.

METHODS

The results of a 75-g, 2-h OGTT were compared with those of a 100-g, 3-h OGTT in 42 pregnant women. The women's mean+/-S.D. age and gestational age were 33.6+/-5.4 years and 28.2+/-4.2 weeks, respectively. Each subject was randomly scheduled within 1 week for both the 75-g and 100-g OGTTs.

RESULTS

The mean plasma glucose concentrations at 1, 2, and 3 h during the 100-g OGTT were significantly higher than those during the 75-g OGTT. Using the Carpenter and Coustan criteria, the prevalence of GDM was 21.4% when using the 100-g, 3-h OGTT, whereas it was found to be at only 7.1% when using the 75-g, 2-h OGTT.

CONCLUSIONS

Plasma glucose responses during the 75-g OGTT were found to be lower than those during the 100-g OGTT. When using the same diagnostic criteria, the prevalence of GDM was also found lower using the 75-g glucose load. It would therefore not be appropriate to use the 75-g OGTT for diagnosing GDM using the criteria and reference values of the 100-g OGTT. To give a comparable prevalence of GDM, the threshold of abnormal plasma glucose levels of the 75-g OGTT would need to be lower than that of the 100-g OGTT.

The effect of early feeding on the neonatal blood glucose level at 1-hour of age

Early infant feeding after birth is being promoted, although it is unclear whether this has any effect on carbohydrate metabolism. We planned to measure the capillary glucose at one hour (1 h) of age in a group of infants from non-diabetic pregnancies using the HemoCue B-Glucose system to see if the timing and method of early feeding would influence this result. Seventy-five term infants were studied, 22 of which were breast-fed, 24 bottle fed and 29 not fed during the first hour after birth. The mean whole blood glucose results were 2.34 mmol/l, 2.52 mmol/l and 2.58 mmol/l respectively (P = NS). The first two groups were fed at a median of 22 minutes before sampling. We conclude that the timing and method of early feeding in the newborn have no significant effect on the blood glucose level measured at 1 h of age, and this remains a reliable outcome measure in studies of glucose metabolism in pregnancy.

The 75 g oral glucose tolerance in pregnancy

A 75 g oral glucose tolerance test was performed between 26 and 32 weeks gestation in 1371 women attending an ante-natal clinic in Melbourne. Gestational diabetes according to various criteria was present in 4.2% (2 h plasma glucose > or = 8.0 mmol/l), 5.2% (2 h plasma glucose > or = 7.8 mmol/l) and 5.5% by the proposed Australian criteria (fasting plasma glucose > or = 5.5 mmol/l and/or 2 h plasma glucose > or = 8.0 mmol/l). The long-term implications of gestational diabetes in the development of diabetes and metabolic abnormalities for both the mother and her child in addition to related infant morbidity emphasise the urgent need for an agreed definition of this condition.