Gestational diabetes: do all women need to be tested?

Understanding the Genetic Landscape of Gestational Diabetes: Insights into the Causes and Consequences of Elevated Glucose Levels in Pregnancy

Background/Objectives: During pregnancy, physiological changes in maternal circulating glucose levels and its metabolism are essential to meet maternal and fetal energy demands. Major changes in glucose metabolism occur throughout pregnancy and consist of higher insulin resistance and a compensatory increase in insulin secretion to maintain glucose homeostasis. For some women, this change is insufficient to maintain normoglycemia, leading to gestational diabetes mellitus (GDM), a condition characterized by maternal glucose intolerance and hyperglycaemia first diagnosed during the second or third trimester of pregnancy. GDM is diagnosed in approximately 14.0% of pregnancies globally, and it is often associated with short- and long-term adverse health outcomes in both mothers and offspring. Although recent studies have highlighted the role of genetic determinants in the development of GDM, research in this area is still lacking, hindering the development of prevention and treatment strategies. Methods: In this paper, we review recent advances in the understanding of genetic determinants of GDM and glycaemic traits during pregnancy. Results/Conclusions: Our review highlights the need for further collaborative efforts as well as larger and more diverse genotyped pregnancy cohorts to deepen our understanding of the genetic aetiology of GDM, address research gaps, and further improve diagnostic and treatment strategies.

Gestational Diabetes Mellitus—Recent Literature Review

Gestational diabetes mellitus (GDM), which is defined as a state of hyperglycemia that is first recognized during pregnancy, is currently the most common medical complication in pregnancy. GDM affects approximately 15% of pregnancies worldwide, accounting for approximately 18 million births annually. Mothers with GDM are at risk of developing gestational hypertension, pre-eclampsia and termination of pregnancy via Caesarean section. In addition, GDM increases the risk of complications, including cardiovascular disease, obesity and impaired carbohydrate metabolism, leading to the development of type 2 diabetes (T2DM) in both the mother and infant. The increase in the incidence of GDM also leads to a significant economic burden and deserves greater attention and awareness. A deeper understanding of the risk factors and pathogenesis becomes a necessity, with particular emphasis on the influence of SARS-CoV-2 and diagnostics, as well as an effective treatment, which may reduce perinatal and metabolic complications. The primary treatments for GDM are diet and increased exercise. Insulin, glibenclamide and metformin can be used to intensify the treatment. This paper provides an overview of the latest reports on the epidemiology, pathogenesis, diagnosis and treatment of GDM based on the literature.

Prevalence and risk factors of gestational diabetes mellitus in Yemen

PURPOSE

Gestational diabetes mellitus (GDM) continues to be a significant health disorder triggering harmful complications in pregnant women and fetuses. Our knowledge of GDM epidemiology in Yemen is largely based on very limited data. The aim of this study was, therefore, to determine the prevalence and risk factors of GDM among pregnant women in Dhamar governorate, Yemen.

PATIENTS AND METHODS

A total of 311 subjects were randomly selected for this cross sectional survey. Health history data and blood samples were collected using a pretested questionnaire. To determine the prevalence of GDM, the fasting and random blood glucose techniques were applied according to the recommendations of the American Diabetes Association, using alternative methods that are more convenient to the targeted population. Poisson's regression model incorporating robust sandwich variance was utilized to assess the association of potential risk factors in developing GDM.

RESULTS

The prevalence of GDM was found to be 5.1% among the study population. Multivariate analysis confirmed age ≥30 years, previous GDM, family history of diabetes, and history of polycystic ovary syndrome as independent risk factors for GDM prevalence. However, body mass index ≥30 kg/m(2) and previous macrosomic baby were found to be dependent risk factors.

CONCLUSION

This study reports new epidemiological information about the prevalence and risk factors of GDM in Yemen. Introduction of proper maternal and neonatal medical care and health education are important in order to save the mother and the baby.

Relationship between mid-trimester ultrasound fetal liver length measurements and gestational diabetes mellitus

BACKGROUND

The aim of the present study was to investigate the relationship between mid-trimester ultrasound fetal liver length (FLL) and gestational diabetes mellitus (GDM) in a high-risk population.

METHODS

A prospective study was performed in 331 women with singleton pregnancies who were at high risk of GDM and were undergoing a mid-trimester ultrasound examination. The ultrasound scan at 23 weeks gestation was followed by a 100-g oral glucose tolerance test (OGTT) at 24 weeks gestation. Correlations between FLL and OGTT results at different time points were tested. Receiver operating characteristic (ROC) analysis of FLL as a potential prognostic factor for GDM was also performed.

RESULTS

In GDM patients, there was a significant positive correlation (P < 0.01) between FLL and OGTT glycemia immediately before and 60, 120, and 180 min after glucose intake. Mean FLL in GDM was significantly higher than in healthy subjects (41.04 vs 31.09 mm, respectively; P < 0.001). When tested as a potential prognostic factor for GDM, fetal liver measurements showed excellent diagnostic performance. The ROC analysis established a cut-off value of FLL of 39 mm for the prediction GDM, with sensitivity of 71.76%, specificity 97.56%, positive predictive value 91.0%, and negative predictive value 90.9%. The usefulness of FLL measurements was supported by a high area under the ROC curve (90.5%).

CONCLUSION

In conclusion, there is a strong correlation between FLL and OGTT results, with FLL possibly serving as a valid marker for the prediction of GDM in high-risk populations.

The effects of adjuvant insulin therapy among pregnant women with IGT who failed to achieve the desired glycemia levels by diet and moderate physical activity

OBJECTIVE

Evaluation of adjuvant insulin therapy effects on glycemic control, perinatal outcome and postpuerperal glucose tolerance in impaired glucose tolerance (IGT) pregnant women who failed to achieve desired glycemic control by dietary regime.

METHODS

A total of 280 participants were classified in two groups: Group A patients continued with dietary regime and Group B patients were treated with adjuvant insulin therapy. Glycemic control was assessed by laboratory and ultrasonograph means. Pregnancy outcomes were evaluated by prevalence of pregnancy induced hypertension (PIH), high birth weight, neonatal hypoglycemia and caesarean section rates. Postpuerperal glucose tolerance was assessed by oral glucose tolerance test (oGTT).

RESULTS

All laboratory and ultrasound indicators of glycemic control had significantly lower values in Group B. Group A women were more likely to develop the EPH (Edema, Proteinuria, Hypertension) syndrome, 20% versus 7.86% (p = 0.003). High birth weight occurred more frequently in Group A, but the difference was not significant (p = 0.197). Higher rate of caesarean delivery was in Group A than in Group B, 16.43% versus 26.43% (p = 0.041). The difference in neonatal hypoglycemia was not significant (p = 0.478). Pathological oGTT results were observed in 73 Group A patients and in 15 Group B patients.

CONCLUSION

Lower caesarean section rates and the EPH syndrome incidence are the benefits of adjuvant insulin therapy in IGT patients.

Sensitivity and specificity of ultrasonography as a screening tool for gestational diabetes mellitus

OBJECTIVE

To evaluate diagnostic accuracy and efficiency of ultrasound markers of gestational diabetes (GDM) and propose an ultrasound based scoring system suitable for screening (UGDS).

METHODS

110 women with singleton pregnancies and established maternal and/or pregnancy related risk factors for GDM were scanned at/or after 24 weeks gestation followed by administration of a 3 hour 100-gram oral glucose tolerance test (oGTT). A number of ultrasound markers were determined/measured, including fetal adipose subcutaneous tissue, asymmetrical macrosomy, cardiac circumference, cardiac width, and interventricular septum thickness, immature appearance of placenta, intensified breathing movements, polyhydramnios and placental thickness. Each ultrasound GDM marker was assigned one point to create the ultrasound gestational diabetes screening score (UGDS).

RESULTS

All ultrasound GDM markers were positively correlated to the disease P < 0.0001. The strongest independent predictor of GDM was an immature appearance of placenta (RR 40.1 95% CI 5.9-271.0, P < 0.0001). Receiver operator characteristics (ROC) showed an area under the curve of 95.7% confirming good ability of UGDS to discriminate between positive and negative oGTT. We propose a UGDS score of 4 providing sensitivity of 90.9%, and specificity 89.6%.

CONCLUSIONS

This study suggests that UGDS is a good predictor of GDM.

Gestational diabetes mellitus: Get, set, go From diabetes capital of the world to diabetes care capital of the world

Screening and diagnosis for gestational diabetes mellitus (GDM) as well as interventions for its management evoke considerable controversy. There are different types of screening methods: universal or risk-based, one step or two step. Different thresholds for diagnosis of GDM have been in vogue. Previous definition and diagnostic criteria had no place for diagnosis of overt diabetes in pregnancy. Following Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study and International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommendations, new screening and diagnostic criteria around the world seem to be gaining consensus. The present recommendation given by IADPSG for screening and diagnosis of diabetes mellitus in pregnancy has two discrete phases. The first is detection of women with overt diabetes not previously diagnosed or treated outside of pregnancy. Universal early testing in populations is recommended at the first prenatal visit. The second phase is a 75-g OGTT at 24-28 week gestation in all women not previously found to have overt diabetes or GDM. ACHOIS and MFMU Network trails have proven benefit in treating hyperglycemias less than what is diagnostic for diabetes. DIPSI has shown the alternative way for resource-challenged communities. Efforts from all stake holders with interest in GDM are required to make the diabetes capital of the world into the diabetes care capital of the world.

Prepregnancy BMI and the risk of gestational diabetes: a systematic review of the literature with meta-analysis

The objective of this study is to assess and quantify the risk for gestational diabetes mellitus (GDM) according to prepregnancy maternal body mass index (BMI). The design is a systematic review of observational studies published in the last 30 years. Four electronic databases were searched for publications (1977-2007). BMI was elected as the only measure of obesity, and all diagnostic criteria for GDM were accepted. Studies with selective screening for GDM were excluded. There were no language restrictions. The methodological quality of primary studies was assessed. Some 1745 citations were screened, and 70 studies (two unpublished) involving 671 945 women were included (59 cohorts and 11 case-controls). Most studies were of high or medium quality. Compared with women with a normal BMI, the unadjusted pooled odds ratio (OR) of an underweight woman developing GDM was 0.75 (95% confidence interval [CI] 0.69 to 0.82). The OR for overweight, moderately obese and morbidly obese women were 1.97 (95% CI 1.77 to 2.19), 3.01 (95% CI 2.34 to 3.87) and 5.55 (95% CI 4.27 to 7.21) respectively. For every 1 kg m(-2) increase in BMI, the prevalence of GDM increased by 0.92% (95% CI 0.73 to 1.10). The risk of GDM is positively associated with prepregnancy BMI. This information is important when counselling women planning a pregnancy.

Associação glicemia de jejum e fatores de risco como teste para rastreamento do diabete gestacional

OBJETIVOS: comparar dois testes de rastreamento do diabete gestacional. MÉTODOS: estudo prospectivo no qual foram avaliadas 356 gestantes, sem diagnóstico prévio do diabete melito, submetidas, de modo independente, a dois testes de rastreamento: associação glicemia de jejum e fator de risco (GJ+FR) e teste oral simplificado de tolerância à glicose (TTG50g). A comparação entre os métodos foi realizada pelos índices de sensibilidade (S), especificidade (E) e valores preditivos positivo (VPP) e negativo (VPN), resultados falsos, positivos (FP) e negativos (FN) e pela diferença dos resultados observados e esperados, avaliada pelo teste do Qui-quadrado (p<0,05). RESULTADOS: a associação GJ+FR determinou a confirmação diagnóstica em maior número de gestantes (187; 52,5%) que o TTG50g (49; 13,8%). Esta diferença foi significativa (p<0,05). A associação GJ+FR apresentou sensibilidade de 83,7% e valor preditivo negativo (VPN) de 95,3% em relação ao TTG50g. CONCLUSÕES: os índices elevados de sensibilidade e VPN da associação GJ+FR em relação ao TTG50g, sua simplicidade, praticidade, baixo custo e fácil replicação permitem sua indicação no rastreamento do diabete gestacional.

Risk factor screening for abnormal glucose tolerance in pregnancy

OBJECTIVES

To assess the prevalence and association of frequently used screening risk factors for gestational diabetes mellitus (GDM) and to compare the validity and cost of universal screening with risk factor screening.

METHOD

A cross-sectional survey of 768 pregnant women at > or = 24 weeks' gestation who were attending the antenatal clinic at the Hospital Universiti Kebangsaan Malaysia (HUKM) was made. Risk factors were determined using a questionnaire. An abnormal oral glucose tolerance test was defined as a 2-h post-prandial blood sugar level of > or = 7.8 mmol/l.

RESULTS

A total of 191 pregnant mothers (24.9%) had GDM. The most commonly identified screening factors were positive family history of diabetes mellitus (31.4%), history of spontaneous abortion (17.8%), vaginal discharge and pruritus vulvae in current pregnancy (16.0%), and maternal age greater than 35 years (14.7%). Five hundred and thirteen mothers (66.8%) had at least one risk factor. All screening risk factors, except past history of diabetes mellitus in previous pregnancy and maternal age, were not significantly associated with abnormal glucose tolerance (GT). Risk factor screening gave a sensitivity of 72.2% and a specificity of 35.0%. Universal screening would cost RM 12.06 while traditional risk factor screening would cost RM 11.15 per identified case and will have missed 53 of the 191 cases.

CONCLUSIONS

Risk factor screening scored poorly in predicting GDM. Cost analysis of universal compared with traditional risk factor screening showed a negligible difference. Thus universal screening appears to be the most reliable method of diagnosing GDM.

Selective versus universal screening for gestational diabetes mellitus: an evaluation of predictive risk factors

OBJECTIVE

To assess whether selective screening for gestational diabetes mellitus (GDM) on the basis of risk-factor assessment is a practicable alternative to universal screening.

DESIGN

Case-control study.

SETTING

A 212-bed regional specialist hospital in Melbourne, providing services in obstetrics and gynaecology, paediatrics, geriatrics and rehabilitation.

SUBJECTS

6,032 women who gave birth at the hospital, May 1996 to August 1997 and November 1997 to August 1998; all were screened for GDM, and 313 were diagnosed with the condition.

MAIN OUTCOME MEASURES

Odds ratios (ORs) for risk factors (age, obesity, family history of diabetes mellitus and high-risk racial heritage) in women with GDM compared to those without GDM; proportion of women with GDM whose diagnosis would have been missed by selective screening.

RESULTS

ORs were 1.9 for age > or = 25 years (95% CI, 1.3-2.7), 2.3 for body mass index > or = 27kg/m2 (95% CI, 1.6-3.3), 2.5 for high-risk racial heritage (95% CI, 2.0-3.2), and 7.1 for family history of diabetes mellitus (95% CI, 5.6-8.9). Other proposed criteria (previous GDM and glycosuria) added no further diagnostic power. Selective screening using the above four criteria would have missed two of 313 cases (0.6%) and could have saved screening up to 1,025 women without GDM (17% of all women).

CONCLUSIONS

Selective screening for GDM based on prior risk assessment can reduce the need for testing, with negligible loss of diagnostic efficiency.

Gestational diabetes mellitus; resource utilization and costs of diagnosis and treatment

The recommendation to test every woman for gestational diabetes mellitus (GDM) has a defined cost. The management of women diagnosed with GDM will use additional health resources. This examines the cost and resource utilization of a consecutive group of women diagnosed over a 1-year period. The cost of testing a woman for GDM is around $10.00 with slight variations depending on the testing procedure. The annual cost of testing in NSW would be less than 1 million dollars. Women diagnosed with GDM used the resources of a diabetes education centre for an average of 2.8 hours and attended for 3.4 (2.3) medical visits. Insulin was required by 18.7% of the women for 9.7 (4.7) weeks using 47.7 (21.2) units each day. Testing women for GDM is a low-cost item. Managing a woman diagnosed with GDM may cost several hundred dollars. Cost reductions could be made by reducing the amount of insulin used and by avoiding hospitalization.