The diagnostic criteria for gestational diabetes: to change or not to change?

Women's views on screening for Type 2 diabetes after gestational diabetes: a systematic review, qualitative synthesis and recommendations for increasing uptake

AIM

Many women do not attend recommended glucose testing following a pregnancy affected by gestational diabetes (GDM). We aimed to synthesize the literature regarding the views and experiences of women with a history of GDM on postpartum glucose testing, focusing on barriers and facilitators to attendance.

METHODS

We systematically identified qualitative studies that examine women's experiences following GDM relating to glucose testing (diabetes screening) or experience of interventions to promote uptake of testing. We conducted a thematic synthesis to develop descriptive and then analytical themes, then developed recommendations to increase uptake based on the findings. We evaluated the quality of each study and the confidence that we had in the recommendations using published checklists.

RESULTS

We included 16 articles after screening 23 160 citations and 129 full texts. We identified four themes of influences relating to the healthcare system and personal factors that affected both ability and motivation to attend: relationship with health care, logistics of appointments and tests, family-related practicalities and concern about diabetes. We developed 10 recommendations addressing diabetes risk information and education, and changes to healthcare systems to promote increased attendance at screening in this population, most with high or moderate confidence.

CONCLUSIONS

We have identified a need to improve women's understanding about Type 2 diabetes and GDM, and to adjust healthcare provision during and after pregnancy to decrease barriers and increase motivation for testing. Encouraging higher uptake by incorporating these recommendations into practice will enable earlier management of diabetes and improve long-term outcomes.

Glycoregulation During Pregnancy

Pregnancy is a period marked by profound changes in a woman’s hormonal status and metabolism, including the development of a carbohydrate-intolerant state. Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy.

The aim of this study was to estimate and analyse the parameters of glycaemic control during pregnancy. We stratified patients into the following three groups according to OGTT results: normal glucose tolerance (NTG), gestational impaired glucose tolerance (GIGT) and GDM.

We investigated 92 pregnant women, diagnosed with vital and desired pregnancy up to 12 weeks of gestation, who had signed informed consent forms. Among them, 7 pregnant women had a spontaneous abortion, while 8 pregnant women dropped out, so a total of 77 pregnant women completed the trial. Most of the women examined had no risk factors (48%), while 35% of the women had one risk factor. The current study demonstrates that normal glucose tolerance was shown in 59 (76.6%) participants, while some form of glucose intolerance (GIGT or GDM) was shown in 18 (23.4%) patients. Our findings revealed an increase in glucose intolerance with advancing pregnancy (in the second and third trimester). In conclusion, we demonstrate that the difference in the quality of glycaemic control during pregnancy is manifested in the second and third trimester, until it manifests in the first trimester. These findings underpin the clinical significance of discovering GDM.

Management of postprandial hyperglycaemia and weight gain in women with gestational diabetes mellitus using a novel telemonitoring system

OBJECTIVES

The purpose of this study was to investigate the effect of remotely delivered telemedicine dietary advice on monitoring of blood glucose levels and weight gain of women with gestational diabetes mellitus (GDM).

METHODS

Women with GDM were recruited and randomly allocated into two groups: a Tele-GDM group that received a telemonitoring device, and a control group that was followed-up traditionally. A telemonitoring service calculated the ratio of reaching or exceeding the pregnancy weight gain target (according to pre-pregnancy weight), following Institute of Medicine guidelines for healthy pregnancy weight gain.

RESULTS

The sample comprised 27 women in the Tele-GDM group and 30 in the control group. At the end of pregnancy, the Tele-GDM group showed significantly lower 2-hour postprandial glucose levels than the control group. Most women in the Tele-GDM group reached their recommended range of weight gain at the end of pregnancy. Additionally, the Tele-GDM group showed significantly lower weight gain than the control group.

CONCLUSIONS

Telemonitoring can facilitate close monitoring of women with GDM and motivate patients to adopt a healthy lifestyle.

Pharmacological treatment of gestational diabetes mellitus: point/counterpoint

Controversies persist over the most efficacious pharmacologic treatment for gestational diabetes mellitus. For purposes of accuracy in this article, the individual American College of Obstetricians and Gynecologists Practice Bulletin and American Diabetes Association Standards of Medical Care positions on each issue are quoted and then deliberated with evidence of counter claims presented in point/counterpoint. This is a review of all the relevant evidence for the most holistic picture possible. The main issues are (1) which diabetic drugs cross the placenta, (2) the quality of evidence and data source validity, (3) the rationale for the designation of glucose control as the primary outcome in gestational diabetes mellitus, and (4) which drugs (metformin, glyburide, or insulin) are most effective in improving secondary outcomes. The concept that 1 drug fits all, whether it be insulin, glyburide, or metformin, is a fallacy. Different drugs provide certain benefits but not all the benefits and not to all patients. In addition, the steps in the gestational diabetes mellitus management decision path and the current cost of the use of insulin, glyburide, or metformin are addressed. In the future, we must consider studying the potential of diabetic drugs that currently are used in nonpregnancy and incorporating the concept of precision medicine in the decision tree to maximize pregnancy outcomes.

Electrochemical and surface plasmon insulin assays on clinical samples

Diabetes is a complex immune disorder that requires extensive medical care beyond glycemic control. Recently, the prevalence of diabetes, particularly type 1 diabetes (T1D), has significantly increased from 5% to 10%, and this has affected the health-associated complication incidences in children and adults. The 2012 statistics by the American Diabetes Association reported that 29.1 million Americans (9.3% of the population) had diabetes, and 86 million Americans (age ≥20 years, an increase from 79 million in 2010) had prediabetes. Personalized glucometers allow diabetes management by easy monitoring of the high millimolar blood glucose levels. In contrast, non-glucose diabetes biomarkers, which have gained considerable attention for early prediction and provide insights about diabetes metabolic pathways, are difficult to measure because of their ultra-low levels in blood. Similarly, insulin pumps, sensors, and insulin monitoring systems are of considerable biomedical significance due to their ever-increasing need for managing diabetic, prediabetic, and pancreatic disorders. Our laboratory focuses on developing electrochemical immunosensors and surface plasmon microarrays for minimally invasive insulin measurements in clinical sample matrices. By utilizing antibodies or aptamers as the insulin-selective biorecognition elements in combination with nanomaterials, we demonstrated a series of selective and clinically sensitive electrochemical and surface plasmon immunoassays. This review provides an overview of different electrochemical and surface plasmon immunoassays for insulin. Considering the paramount importance of diabetes diagnosis, treatment, and management and insulin pumps and monitoring devices with focus on both T1D (insulin-deficient condition) and type 2 diabetes (insulin-resistant condition), this review on insulin bioassays is timely and significant.

Use of the National Diabetes Data Group and the Carpenter-Coustan criteria for assessing gestational diabetes mellitus and risk of adverse pregnancy outcome

Background

The influence of different diagnostic thresholds for gestational diabetes mellitus (GDM) on pregnancy outcomes is not fully understood. Degrees of glucose intolerance according to the Carpenter-Coustan (CC) criteria were less severe than the National Diabetes Data Group (NDDG) criteria for GDM. Recent studies have shown inconsistent results regarding the risk of adverse pregnancy outcomes between the NDDG and CC criteria. Therefore, the objective of this study was to investigate whether pregnant women who met only the CC criteria but not the NDDG criteria and those who met the NDDG criteria had increased risks of adverse pregnancy outcomes compared to a negative screening group.

Methods

A total of 11,486 Taiwanese pregnancies were enrolled in a retrospective cohort study. The study subjects were classified as follows: (1) negative screening group: women with negative 50-g glucose challenge test (GCT) results, (2) false-positive screening group: women with positive GCT results and negative 100-g OGTT results according to both CC and NDDG criteria, (3) CC-only-GDM group: women with positive GCT results plus GDM diagnosis meeting the CC but not the NDDG criteria, and (4) NDDG-GDM group: women diagnosed with GDM using the NDDG criteria. Multiple mixed effects logistic regression analysis was used to examine the relationships between the groups and pregnancy outcomes.

Results

There were 9002 (78.4 %), 1776 (15.5 %), 251 (2.2 %), and 457 (4.0 %) study pregnancies in the 4 groups. Compared with the negative screening group, the maternal outcomes were not different within groups except for gestational hypertension/preeclampsia. For neonatal outcomes, the CC-only-GDM group had significantly greater risks of macrosomia, low birth weight, and admission to a neonatal intensive care unit [adjusted odds ratio (aOR), (95 % confidence interval, CI): 2.73 (1.18–6.31), 1.64 (1.01–2.64), and 1.61 (1.05–2.46), respectively]. The NDDG-GDM group also showed significantly greater risks, and the false-positive screening group showed no differences from the negative screening group.

Conclusion

Women who met only the CC criteria and women who met NDDG criteria had significant increased risks of adverse neonatal outcomes. This evidence adds important information to the current debate about the diagnostic criteria for GDM regarding pregnancy outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1030-9) contains supplementary material, which is available to authorized users.

Magnetic Optical Microarray Imager for Diagnosing Type of Diabetes in Clinical Blood Serum Samples

Due to rapidly rising rates of diabetes and prediabetic conditions worldwide and the associated lethal complications, it is imperative to devise new diagnostic tools that reliably and directly measure insulin levels in clinical samples. Herein, we report a simple and sensitive direct imaging of insulin levels in diabetic patient samples using a surface plasmon resonance microarray imager (SPRi). To enhance sensitivity, we utilized magnetic nanoparticles (MNPs) to capture insulin from serum samples either directly or via a capture antibody immobilized on MNPs. The insulin-captured nanoparticles were allowed to bind surface insulin-antibody for detection from pixel intensity increase using a charge coupled device (CCD) built-in with the SPRi. We have compared the analytical figures-of-merit of the SPRi immunoarray on detecting insulin prepared in various percentages of serum solutions. A four parameter logistic model was used to obtain the best fit of microarray responses with insulin concentration and indicated the cooperative binding of insulin-nanoparticle conjugates to surface antibody in both the buffer insulin and the serum insulin conjugates with MNPs. The cooperativity effect is attributed to the greater association of magnetic nanoparticle-bound insulin molecules with increasing concentration of insulin binding to surface antibody. This is the first report of an SPRi immunoarray to accomplish clinical diagnosis of diabetic and prediabetic conditions based on insulin levels with serum matrix effect analysis and comparison between direct and sandwich insulin assay formats.

Metformin versus insulin in gestational diabetes mellitus: a meta-analysis of randomized clinical trials

BACKGROUND

Metformin is widely used in treatment of type 2 diabetes. However, whether it is safe for use in pregnancy is controversial.

METHODS

A search for relevant studies were performed using PubMed (1948-2014), Embase (1974-2014), the Web of knowledge (1950-2014), and the Cochrane database, included all randomized control trials published in English.

RESULTS

Eight RCTs (1712 patients with gestational diabetes mellitus) were retrieved; of those 853 patients were given metformin, and 859 patients were given insulin. Our results showed that metformin does not increase risk of prematurity (RR = 1.26; 95 % CI [0.89, 1.79], P = 0.19). In addition, metformin can either decrease the total weight gain [MD = -1.49, 95 % CI (-2.66, -0.31), P = 0.01] or weight gain after randomization [MD = -1.23, 95 % CI (-1.75, -0.71), P < 0.00001]. No significant differences were observed in patients with pre-eclampsia [RR = 0.82, 95 % CI (0.56, 1.2), P = 0.32] or caesarean section [RR = 0.93, 95 % CI (0.75, 1.16), P = 0.53]. Use of metformin also significantly decreased the risk of neonatal hypoglycemia [RR = 0.58, 95 % CI (0.43, 0.78), P = 0.0003] and admission rates to neonatal intensive care units [RR = 0.74, 95 % CI (0.61, 0.89), P = 0.002]. No other adverse effects were observed, such as hyperbilirubinaemia [RR = 0.83, 95 % CI (0.64, 1.08), P = 0.16], large for gestational age [RR = 0.85, 95 % CI (0.68, 1.05), P = 0.14], small for gestational age [RR = 0.92, 95 % CI (0.61, 1.39), P = 0.69], macrosomia [RR = 0.75, 95 % CI (0.54, 1.03), P = 0.07] or respiratory distress syndrome [RR = 0.88, 95 % CI (0.55, 1.41), P = 0.6].

CONCLUSIONS

Metformin may be beneficial in treating gestational diabetes. However, even more studies are needed to provide more evidence for the future use of metformin.

Managing Diabetes in Pregnancy Using Cell Phone/Internet Technology

In Brief For pregnant women with diabetes, using cell phone/Internet technology to track and report self-monitoring of blood glucose results improves compliance and satisfaction compared to using the more traditional methods of log books, telephone calls, and voicemail messages.

Gestational diabetes: differences between the current international diagnostic criteria and implications of switching to IADPSG

AIMS

To highlight the differences between eight international expert panel diagnostic criteria (either current or outdated but in use) for the diagnosis of gestational diabetes mellitus (GDM) and implications of switching to the International Association of Diabetes in Pregnancy Study Groups (IADPSG) criterion.

METHODS

2337 pregnant women underwent a 75-g oral glucose tolerance test as part of a universal screening protocol. The GDM prevalence and number of women classified differently were compared between the criteria of the American Diabetes Association (2003); Australasian Diabetes in Pregnancy Society (1998); the Canadian Diabetes Association, CDA (2003 & 2013); the European Association for the Study of Diabetes (1996); IADPSG (2010); the New Zealand Society for the Study of Diabetes (2004) and the World Health Organization (1999).

RESULTS

The prevalence varied from 9.2% to 45.3% with the different criteria. The IADPSG compared a) best with CDA 2013 [356(15.2%) women classified differently, (kappa, k=68.3%)] and b) worst with CDA 2003 [843 (36.1%) women classified differently, (k=21.8%)]; p<0.001.Switching to IADPSG from the original criteria would increase the prevalence 1.5-4.9 times.

CONCLUSIONS

In 2015, the various international guidelines for GDM continue to show major discrepancies in the prevalence and the women classified dissimilarly. A consensus on a single global guideline would be a giant leap forward.

The effects of implementing the International Association of Diabetes and Pregnancy Study Groups criteria for diagnosing gestational diabetes on maternal and neonatal outcomes

BACKGROUND

In 2010, the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) recommended a new strategy for the screening and diagnosis of gestational diabetes mellitus (GDM). However, no study has indicated that adopting the IADPSG recommendations improves perinatal outcomes. The objective of this study was to evaluate the effects of implementing the IADPSG criteria for diagnosing GDM on maternal and neonatal outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

Previously, we used a two-step approach (a 1-h, 50-g glucose challenge test followed by a 3-h, 100-g glucose tolerance test when indicated) to screen for and diagnose GDM. In July 2011, we adopted the IADPSG recommendations in our routine obstetric care. In this study, we retrospectively compared the rates of various maternal and neonatal outcomes in all women who delivered after 24 weeks of gestation during the periods before (P1, between January 1, 2009 and December 31, 2010) and after (P2, between January 1, 2012 and December 31, 2013) the IADPSG criteria were implemented. Pregnancies complicated by multiple gestations, fetal chromosomal or structural anomalies, and pre-pregnancy diabetes mellitus were excluded. Our results showed that the incidence of GDM increased from 4.6% using the two-step method to 12.4% using the IADPSG criteria. Compared to the women in P1, the women in P2 experienced less weight gain during pregnancy, lower birth weights, shorter labor courses, and lower rates of macrosomia (<4000 g) and large-for-gestational age (LGA) infants. P2 was a significant independent factor against macrosomia (adjusted odds ratio [OR] 0.63, 95% confidence interval [CI] 0.43-0.90) and LGA (adjusted OR 0.74, 95% CI 0.61-0.89) after multivariable logistic regression analysis.

CONCLUSIONS/SIGNIFICANCE

The adoption of the IADPSG criteria for diagnosis of GDM was associated with significant reductions in maternal weight gain during pregnancy, birth weights, and the rates of macrosomia and LGA.

Early third trimester maternal response to glucose challenge and pregnancy outcome in Chinese women-relationship between upper distribution level and recommended diagnostic criteria

BACKGROUND/OBJECTIVES

The objective of this study was to examine the relationship between upper distribution levels of glucose values in the 75-g oral glucose tolerance test (OGTT) and recommended diagnostic criteria for gestational diabetes mellitus (GDM) and adverse pregnancy outcomes.

SUBJECTS/METHODS

The distribution of the OGTT 2-h values of 13,501 pregnant women, which were below the World Health Organization (WHO) threshold for overt diabetes mellitus (DM), and managed in one teaching hospital in China, was reviewed and related to maternal characteristics and pregnancy outcomes.

RESULTS

For the entire group, the 90th and 95th percentile values of the OGTT 2-h glucose level, respectively, were close to the diagnostic cutoff values of the WHO and International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. For adverse maternal outcomes, glucose level above the 90th percentile value was associated with increased hypertensive disorders, whereas no difference was seen with cutoff using the 95th percentile value. For perinatal outcomes, the 90th percentile was associated with increased neonatal intensive care unit admission and hypoglycemia, whereas the 95th percentile showed in addition association with phototherapy for jaundice and 5th-minute Apgar score <7. Although no differences in the incidence of adverse pregnancy outcomes were found using the different cutoffs, the >95th percentile cutoff value would have missed out 33.3-56.7% of the cases of adverse outcomes that would otherwise have been attributed to GDM.

CONCLUSIONS

Further studies are warranted to clarify which diagnostic criterion is most appropriate universally to identify adverse pregnancy outcomes attributed to GDM, and which could be mitigated with treatment specific for GDM.

Reproductive history and progression of lower urinary tract symptoms in women: results from a population-based cohort study

OBJECTIVE

To examine whether reproductive history and related conditions are associated with the development and persistence of lower urinary tract symptoms (LUTS) other than urinary incontinence in a racially and/or ethnically diverse population-based sample of women.

MATERIALS AND METHODS

The Boston Area Community Health Survey enrolled 3201 women aged 30-79 years of black, Hispanic, or white race and/or ethnicity. Baseline and 5-year follow-up interviews were completed by 2534 women (conditional response rate, 83.4%). The association between reproductive history factors and population-weighted estimates of LUTS progression and persistence was tested using multivariable logistic regression models.

RESULTS

Between baseline and 5-year follow-up, 23.9% women had LUTS progression. In age-adjusted models, women who had delivered ≥2 childbirths had higher odds of LUTS progression, but the association was completely accounted for by vaginal child delivery (eg, 2 vaginal childbirths vs none, multivariable-adjusted odds ratio = 2.21; 95% CI, 1.46-3.35; P <.001). No increased odds of LUTS progression were found for women with only 1 vaginal delivery or who only had cesarean section(s). Uterine prolapse was associated with higher odds of LUTS progression (multivariable-adjusted odds ratio = 3.05; 95% CI, 1.43-6.50; P = .004). Gestational diabetes was associated with approximately twice the odds of LUTS progression, but only among younger women (interaction P = .003).

CONCLUSION

In this cohort study, ≥2 vaginal child deliveries, uterine prolapse, and among younger women, gestational diabetes were robust predictors of LUTS progression. Clinicians should assess the presence of bothersome urinary frequency, urgency, and voiding symptoms among women who have had multiple vaginal childbirths or gestational diabetes.

Predictors and clinical implications of a false negative glucose challenge test in pregnancy

OBJECTIVE

A common approach to screening for glucose intolerance in pregnant women is the use of a 50g glucose challenge test (GCT) in the late second trimester, followed by a diagnostic oral glucose tolerance test (OGTT) when the GCT is positive (1-hour post-challenge blood glucose ≥ 7.8 mmol/L). As women with a negative GCT do not undergo the diagnostic OGTT, it is possible that they could have undiagnosed gestational diabetes (GDM) or gestational impaired glucose tolerance (GIGT). Thus, we sought to characterize predictors of a false negative GCT and its clinical implications.

METHODS

Two hundred two women with a negative GCT screening test underwent subsequent OGTT, which enabled their stratification into two groups: (1) those with normal glucose tolerance on OGTT (n = 166) and (2) those with either GDM (n = 8) or GIGT (n = 28).

RESULTS

The 36 women found to have GDM or GIGT at the time of OGTT had higher GCT glucose values than those with normal glucose tolerance (mean 6.6 mmol/L vs. 5.9 mmol/L, P < 0.001), as well as poorer insulin sensitivity (P = 0.004) and pancreatic beta-cell function (P < 0.001). On logistic regression analysis, the only significant independent predictor of GDM/GIGT was the GCT glucose value (OR 2.19; 95% CI 1.40 to 3.41, P < 0.001). However, there was no clear GCT glucose threshold for identifying GDM/GIGT, consistent with its modest area under the receiver operating characteristic curve (0.71). Importantly, there were also no differences between the two groups in median length of gestation, median birth weight, prevalence of macrosomia, or proportion of low Apgar scores.

CONCLUSION

False negative GCTs cannot be readily predicted by risk factors. However, their clinical implications at delivery may be benign.

Drug metabolism and transport during pregnancy: how does drug disposition change during pregnancy and what are the mechanisms that cause such changes?

There is increasing evidence that pregnancy alters the function of drug-metabolizing enzymes and drug transporters in a gestational-stage and tissue-specific manner. In vivo probe studies have shown that the activity of several hepatic cytochrome P450 enzymes, such as CYP2D6 and CYP3A4, is increased during pregnancy, whereas the activity of others, such as CYP1A2, is decreased. The activity of some renal transporters, including organic cation transporter and P-glycoprotein, also appears to be increased during pregnancy. Although much has been learned, significant gaps still exist in our understanding of the spectrum of drug metabolism and transport genes affected, gestational age-dependent changes in the activity of encoded drug metabolizing and transporting processes, and the mechanisms of pregnancy-induced alterations. In this issue of Drug Metabolism and Disposition, a series of articles is presented that address the predictability, mechanisms, and magnitude of changes in drug metabolism and transport processes during pregnancy. The articles highlight state-of-the-art approaches to studying mechanisms of changes in drug disposition during pregnancy, and illustrate the use and integration of data from in vitro models, animal studies, and human clinical studies. The findings presented show the complex inter-relationships between multiple regulators of drug metabolism and transport genes, such as estrogens, progesterone, and growth hormone, and their effects on enzyme and transporter expression in different tissues. The studies provide the impetus for a mechanism- and evidence-based approach to optimally managing drug therapies during pregnancy and improving treatment outcomes.

New guidelines for diagnosis of gestational diabetes: pathology-based impact assessment

BACKGROUND

A recent study indicated an average of 19.5% abnormal oral glucose tolerance in antenatal clients per year.

AIM

The purpose of this study was to determine the impact on gestational diabetes cases due to new guidelines for diagnosis and classification of hyperglycaemia in pregnancy.

MATERIALS AND METHODS

This study reviewed the archived clinical pathology data on oral glucose tolerance tests performed between January 1999 and December 2008 on antenatal clients (N = 615). The cases were reviewed to determine changes if any in percentage of gestational diabetes due to new guidelines.

RESULTS

Over the 10 years period, a yearly average of additional 10.8% antenatal cases suggestive of gestational diabetes was observed due to the new recommended thresholds. Further, the average yearly incidence would have increased from 8.8 cases to 16.2 cases, which translates to almost 46% increase in the prospective numbers of gestational diabetes.

CONCLUSIONS

This report presents the extent of how the new recommended guidelines for diagnosis and classification of hyperglycaemia in pregnancy could increase the prevalence of gestational diabetes. It also provides pathology-based evidence for the epidemiology of gestational diabetes mellitus and allows for planning the costs that would be attendant to the full implementation of the new guidelines.