Oral hypoglycemic agents vs insulin in management of gestational diabetes: a systematic review and metaanalysis

Gestational diabetes mellitus - more than the eye can see - a warning sign for future maternal health with transgenerational impact

Gestational diabetes mellitus (GDM) is regarded by many as maternal maladaptation to physiological insulin resistance during the second half of pregnancy. However, recent evidence indicates that alterations in carbohydrate metabolism can already be detected in early pregnancy. This observation, the increasing prevalence of GDM, and the significant short and long-term implications for the mother and offspring call for reevaluation of the conceptual paradigm of GDM as a syndrome. This review will present evidence for the syndromic nature of GDM and the controversies regarding screening, diagnosis, management, and treatment.

Metformin in gestational diabetes: physiological actions and clinical applications

Metformin is an effective oral hypoglycaemic agent used in the treatment of type 2 diabetes mellitus; however, its use in pregnancy for the treatment of gestational diabetes mellitus (GDM) remains controversial owing to concerns around safety and efficacy. This comprehensive review outlines the physiological metabolic functions of metformin and synthesizes existing literature and key knowledge gaps pertaining to the use of metformin in pregnancy across various end points in women with GDM. On the basis of current evidence, metformin reduces gestational weight gain, neonatal hypoglycaemia and macrosomia and increases insulin sensitivity. However, considerable heterogeneity between existing studies and the grouping of aggregate and often inharmonious data within meta-analyses has led to disparate findings regarding the efficacy of metformin in treating hyperglycaemia in GDM. Innovative analytical approaches with stratification by individual-level characteristics (for example, obesity, ethnicity, GDM severity and so on) and treatment regimens (diagnostic criteria, treatment timing and follow-up duration) are needed to establish efficacy across a range of end points and to identify which, if any, subgroups might benefit from metformin treatment during pregnancy.

Antenatal maternal hypoglycemia in women with gestational diabetes mellitus and neonatal outcomes

OBJECTIVE

To examine the prevalence of antenatal maternal hypoglycemia after initiation of pharmacotherapy for gestational diabetes mellitus (GDMA2) and its association with pregnancy outcomes.

STUDY DESIGN

Retrospective cohort of GDMA2 women receiving either insulin or oral hypoglycemic agents. Composite neonatal outcome included macrosomia, jaundice, respiratory distress syndrome, large for gestational age, shoulder dystocia, birth trauma, 5-minute Apgar < 7, and neonatal hypoglycemia, and was compared between women with and without hypoglycemia using bivariate and multivariate analyses.

RESULTS

Of 489 women included in the study, 95 (19.4%) had at least one episode of hypoglycemia, most often in the setting of glyburide. Newborns exposed to maternal hypoglycemia had higher rates of the composite neonatal outcome (54.7% vs. 38.3%, p = 0.004). After controlling for confounding factors, maternal hypoglycemia remained independently associated with the composite neonatal outcome (aOR = 1.69, 95% CI 1.04-2.72).

CONCLUSION

Maternal hypoglycemia in GDMA2 was associated with higher rates of adverse neonatal outcomes.

Management of cardiovascular risk factors during pregnancy

Cardiovascular (CV) risk factors are rising among women of reproductive age. Obesity, hyperlipidaemia, diabetes, and hypertension are associated with adverse pregnancy outcomes and increased CV disease (CVD) risk following pregnancy. Pre-conception counselling and longitudinal postpartum follow-up with ongoing CV risk factor screening are critical for early CVD prevention, though significant racial/ethnic disparities in access to care result in significant gaps. This review summarises the recommended management of CV risk factors during and after pregnancy. For obesity, prevention of excessive weight gain is critical. Except in rare cases, lipid-lowering therapies for women with hyperlipidaemia should be stopped before pregnancy. Women with diabetes in pregnancy should maintain tight glucose control, with hemolgobin A1c (HbA1c) <6.5% to prevent congenital abnormalities. Hypertensive disorders of pregnancy are associated with high maternal and neonatal morbidity and require long-term follow-up to prevent future CVD. Finally, this review highlights the lack of clinical trials informing optimal treatment strategies of CV risk factors during and after pregnancy. Further research is needed to better understand how to improve long-term CV health among this high-risk population.

Correlates of Insulin Selection as a First-Line Pharmacological Treatment for Gestational Diabetes

OBJECTIVE

The aim of this study was to investigate prenatal factors associated with insulin prescription as a first-line pharmacotherapy for gestational diabetes mellitus (GDM; compared with oral antidiabetic medication) after failed medical nutrition therapy.

STUDY DESIGN

This is a retrospective cohort study of 437 women with a singleton pregnancy and diagnosis of A2GDM (GDM requiring pharmacotherapy), delivering in a university hospital between 2015 and 2019. Maternal sociodemographic and clinical characteristics, as well as GDM-related factors, including provider type that manages GDM, were compared between women who received insulin versus oral antidiabetic medication (metformin or glyburide) as the first-line pharmacotherapy using univariable and multivariable analyses.

RESULTS

In univariable analysis, maternal age, race and ethnicity, insurance, chronic hypertension, gestational age at GDM diagnosis, glucose level after 50-g glucose loading test, and provider type were associated with insulin prescription. In multivariable analysis, after adjusting for sociodemographic and clinical maternal factors, GDM characteristics and provider type, Hispanic ethnicity (0.26, 95% confidence interval [CI]: 0.09-0.73), and lack of insurance (0.34, 95% CI: 0.13-0.89) remained associated with lower odds of insulin prescription, whereas endocrinology management of GDM (compared with obstetrics and gynecology [OBGYN]) (8.07, 95% CI: 3.27-19.90) remained associated with higher odds of insulin prescription.

CONCLUSION

Women of Hispanic ethnicity and women with no insurance were less likely to receive insulin and more likely to receive oral antidiabetic medication for GDM pharmacotherapy, while management by endocrinology was associated with higher odds of insulin prescription.This finding deserves more investigation to understand if differences are due to patient choice or a health disparity in the choice of pharmacologic agent for A2GDM.

KEY POINTS

· Insulin is recommended as a first-line pharmacotherapy for gestational diabetes.. · Women of Hispanic ethnicity were less likely to receive insulin as first line.. · Lack of insurance was also associated with lower odds of insulin prescription..

Effectiveness of antidiabetic agents for treatment of gestational diabetes: A methodological quality assessment of meta-analyses and network meta-analysis

AIMS/INTRODUCTION

Despite there being several meta-analyses on the effects of antidiabetic agents in patients with gestational diabetes mellitus, the reliability of their findings is a concern, mainly due to undetermined methodological quality of these studies. This study aimed to assess the methodological quality of available meta-analyses and provide a summary estimation of the effectiveness of treatments modalities.

MATERIALS AND METHODS

PubMed, Web of Science and Scopus databases were comprehensively searched for retrieving relevant meta-analyses published in English up to May 2020. A Measurement Tool to Assess Systematic Reviews (AMSTAR-2) was applied to evaluate methodological quality of eligible meta-analyses. A network meta-analysis was used to calculate the pooled odds ratio of maternal and neonatal outcomes in gestational diabetes mellitus patients treated with metformin or glyburide compared with those treated with insulin. The rank network analysis was carried out for ranking of the treatments and reporting the most efficient treatment.

RESULTS

A total of 27 and 17 studies were included for qualitative and quantitative syntheses, respectively; of these, just four studies were classified as high quality. The results showed that metformin had the highest probability of being the best treatment, compared with insulin and glyburide, for the majority of adverse neonatal outcomes, whereas glyburide was the best treatment in reducing the risk of adverse maternal outcomes. The results were not significantly changed after excluding low-quality studies.

CONCLUSIONS

This review study of available literature shows that metformin can be a superior option in most neonatal and maternal adverse pregnancy outcomes in women with gestational diabetes mellitus; the results need to be further updated by including future more qualified studies.

Diagnosis and Management of Gestational Diabetes Mellitus: An Overview of National and International Guidelines

Importance

Gestational diabetes mellitus (GDM) represents one of the most frequent complications of pregnancy and is associated with increased maternal and neonatal morbidity. Its incidence is rising, mostly due to an increase in maternal age and maternal obesity rate.

Objective

The aim of this study was to review and compare the recommendations of the most recently published guidelines on the diagnosis and management of this condition.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence (NICE), the International Federation of Gynecology and Obstetrics, the Australasian Diabetes in Pregnancy Society (ADIPS), the Society of Obstetricians and Gynecologists of Canada (SOGC), the American College of Obstetricians and Gynecologists (ACOG), the American Diabetes Association, and the Endocrine Society on gestational diabetes mellitus was carried out.

Results

The NICE guideline recommends targeted screening only for women with risk factors, whereas the International Federation of Gynecology and Obstetrics, ADIPS, SOGC, and the ACOG recommend screening for all pregnant women at 24 to 28 weeks of gestation in order to diagnose and effectively manage GDM; they also state that women with additional risk factors should be screened earlier (ie, in the first trimester) and retested at 24 to 28 weeks, if the initial test is negative. These guidelines describe similar risk factors for GDM and suggest the same thresholds for the diagnosis of GDM when using a 75-g 2-hour oral glucose tolerance test. Of note, the NICE only assesses the fasting and the 2-hour postprandial glucose levels for the diagnosis of GDM. Moreover, the SOGC and the ACOG do not recommend this test as the optimal screening method. The Endocrine Society alone, on the other hand, recommends the universal testing of all pregnant women for diabetes before 13 weeks of gestation or as soon as they attend the antenatal service and retesting at 24 to 28 weeks if the initial results are normal. In addition, there is a general consensus on the appropriate ultrasound surveillance of pregnancies complicated with GDM, and all the medical societies, except the ADIPS, recommend self-monitoring of capillary glucose to assess the glycemic control and set the same targets for fasting and postprandial glucose levels. There is also agreement that lifestyle modifications should be the first-line treatment; however, the reviewed guidelines disagree on the medical management of GDM. In addition, there are controversies regarding the timing of delivery, the utility of hemoglobin A_1c measurement, and the postpartum and lifelong screening for persistent hyperglycemia and type 2 diabetes. However, all the guidelines state that all women in pregnancies complicated by GDM should undergo a glycemic test at around 6 to 12 weeks after delivery. Finally, there is a universal consensus on the importance of breastfeeding and preconception screening before future pregnancies.

Conclusions

As GDM is an increasingly common complication of pregnancy, it is of paramount importance that inconsistencies between national and international guidelines should encourage research to resolve the issues of controversy and allow uniform international protocols for the diagnosis and management of GDM, in order to safely guide clinical practice and subsequently improve perinatal and maternal outcomes.

Metformin is comparable to insulin for pharmacotherapy in gestational diabetes mellitus: A network meta-analysis evaluating 6046 women

CONTEXT

The comparative efficacy of gestational diabetes (GDM) treatments lack conclusive evidence for choice of first-line treatment.

OBJECTIVES

The aim of this study was to compare the efficacy of metformin and glibenclamide to insulin using a core outcome set (COS) to unify outcomes across trials investigating the treatment of gestational diabetes mellitus.

STUDY DESIGN

A network meta-analysis (NMA) was conducted.

DATA-SOURCE

PubMed, Embase, and Cochrane Controlled Register of Trials were searched from inception to January 2020.

STUDY SELECTION

RCTs that enrolled pregnant women who were diagnosed with GDM and that compared the efficacy of different pharmacological interventions for the treatment of GDM were included.

META-ANALYSIS

A generalized pairwise modelling framework was employed.

RESULTS

A total of 38 RCTs with 6046 participants were included in the network meta-analysis. Compared to insulin, the estimated effect of metformin indicated improvements for weight gain (WMD -2·39 kg; 95% CI -3·31 to -1·46), maternal hypoglycemia (OR 0.34; 95% CI 0.12 to 0·97) and LGA (OR 0.61; 95% CI 0.38 to 0·98). There were also improvements in estimated effects for neonatal hypoglycemia (OR 0.48; 95% CI 0.19 to 1·25), pregnancy induced hypertension (OR 0.63; 95% CI 0.37 to 1·06), and preeclampsia (OR 0.74; 95% CI 0.538 to 1·04), though with limited evidence against our model hypothesis of equivalence with insulin for these outcomes.

CONCLUSION

Metformin is, at least, comparable to insulin for the treatment of GDM. Glibenclamide appears less favorable, in comparison to insulin, than metformin.

The timing of initiation of pharmacotherapy for women with gestational diabetes mellitus

BACKGROUND

The decision to initiate pharmacotherapy is integral in the care for pregnant women with gestational diabetes mellitus (GDM). We sought to compare pregnancy outcomes between two threshold percentages of elevated glucose values prior to initiation of pharmacotherapy for GDM. We hypothesized that a lower threshold at pharmacotherapy initiation will be associated with lower rates of adverse perinatal outcomes.

METHODS

This was a retrospective cohort study of women with GDM delivering in a single tertiary care center. Pregnancy outcomes were compared using bivariable and multivariable analyses between women who started pharmacotherapy (insulin or oral hypoglycemic agent) after a failed trial of dietary modifications at two different ranges of elevated capillary blood glucose (CBG) values: Group 1 when 20-39% CBG values were above goal; Group 2 when ≥40% CBG values were above goal. The primary outcome was a composite GDM-associated neonatal adverse outcome that included: macrosomia, large for gestational age (LGA), shoulder dystocia, hypoglycemia, hyperbilirubinemia requiring phototherapy, respiratory distress syndrome, stillbirth, and neonatal demise. Secondary outcomes included cesarean delivery, preterm birth (< 37 weeks), neonatal intensive care unit (NICU) admission, and small for gestational age (SGA).

RESULTS

A total of 417 women were included in the study. In univariable analysis, the composite neonatal outcome was statistically significantly higher in Group 2 compared to Group 1 (47.9% vs. 31.4%, p = 0.001). In addition, rates of preterm birth (15.7% vs 7.4%, p = 0.011), NICU admission (11.7% vs 4.0%, p = 0.006), and LGA (21.2% vs 9.1% p = 0.001) were higher in Group 2. In contrast, higher rates of SGA were noted in Group 1 (8.0% vs. 2.9%, p = 0.019). There was no difference in cesarean section rates. These findings persisted in multivariable analysis after adjusting for confounding factors (composite neonatal outcome aOR = 0.50, 95%CI [0.31-0.78]).

CONCLUSIONS

Initiation of pharmacotherapy for GDM when 20-39% of CBG values are above goal, compared to ≥40%, was associated with decreased rates of adverse neonatal outcomes attributable to GDM. This was accompanied by higher rates of SGA among women receiving pharmacotherapy at the lower threshold. Additional studies are required to identify the optimal threshold of abnormal CBG values to initiate pharmacotherapy for GDM.

Glyburide therapy for gestational diabetes: Glycaemic control, maternal hypoglycaemia, and treatment failure

AIMS

The recommended first-line treatment for women with gestational diabetes mellitus (GDM) in the case of failure of diet is insulin. Recent results suggest that there is a potential role for glyburide therapy and highlight the need for better knowledge of glycaemic control with glyburide. The objective of this study was to describe and quantify in women with GDM the quality of glycaemic control, including the risk of maternal hypoglycaemia and of therapy failure.

METHODS

This is a secondary analysis of the French INDAO non-inferiority trial from 2012 to 2016, in which 890 women with GDM randomized to receive glyburide or insulin treatment were compared for perinatal outcomes. Blood glucose concentrations were assessed prospectively during pregnancy. Optimal glycaemic control was defined as less than 20% of blood glucose values exceeding the targets.

RESULTS

More than 50% of the women had optimal glycaemic control with glyburide, similar to that with insulin. Around 40% of the women had at least one episode of hypoglycaemia, more than with insulin. However, those hypoglycaemic episodes were mostly moderate and the rate of severe hypoglycaemia decreased significantly during the course of the trial. Failure of glyburide treatment (switch to insulin therapy) occurred in 18% of women and had few predictors. However, when failure occurred, glycaemic control was improved after switching to insulin.

CONCLUSIONS

Glyburide is an effective treatment for reaching glycaemic goals during pregnancy in women with GDM. The risk of maternal hypoglycaemia may be minimized by clinical practice experience. These findings could be taken into account in the management of GDM.

Progress in the Development of Chitosan Based Insulin Delivery Systems: A Systematic Literature Review

Diabetes mellitus is a chronic disease that is considered a worldwide epidemic, and its control is a constant challenge for health systems. Since insulin had its first successful use, scientists have researched to improve the desired effects and reduce side-effects. Over the years, the challenge has been to increase adherence to treatment and improve the quality of life for diabetics by developing an insulin delivery system. This systematic review (SR) analyses experimental articles from 1998 to 2018 related to the development of the chitosan/insulin delivery system (CIDS). Automated support: Start tool was used to perform part of these activities. The search terms “insulin”, “delivery or release system”, and “chitosan” were used to retrieve articles in PubMed, Science Direct, Engineering Village, and HubMed. A total of 55 articles were selected. The overview, phase, model, way of administration, and the efficiency of CIDS were analyzed. According to SR results, most of the articles were published from 2010 onwards, representing 72.7% of the selected papers, and research groups from China publicized 23.6% of the selected articles. According to the SR, 51% of the studies were carried out in vivo and 45% in vitro. Most of the systems were nanoparticle based (54.8%), and oral administration was proposed by 60.0% of the selected articles. Only 36.4% performed loaded capacity and encapsulation efficiency assays, and 24 h (16.4%), 12 h (12.7%), and 6 h (11.0%) were the most frequent insulin release times. Chitosan’s intrinsic characteristics, which include biodegradability, biocompatibility, adhesiveness, the ability to open epithelial tight junctions to allow an increase in the paracellular transport of macromolecular drugs, such as insulin, and the fact that it does not result in allergic reactions in the human body after implantation, injection, topical application or ingestion, have contributed to the increase in research of CIDS over the years. However, the number of studies is still limited and the use of an alternative form of insulin administration is not yet possible. Thus, more studies in this area, aiming for the development of an insulin delivery system that can promote more adherence to the treatment and patient comfort, are required.

Metformin in Pregnancy Study (MiPS): protocol for a systematic review with individual patient data meta-analysis

INTRODUCTION

Gestational diabetes mellitus (GDM) is a common disorder of pregnancy and contributes to adverse pregnancy outcomes. Metformin is often used for the prevention and management of GDM; however, its use in pregnancy continues to be debated. The Metformin in Pregnancy Study aims to use individual patient data (IPD) meta-analysis to clarify the efficacy and safety of metformin use in pregnancy and to identify relevant knowledge gaps.

METHODS AND ANALYSIS

MEDLINE, EMBASE and all Evidence-Based Medicine will be systematically searched for randomised controlled trials (RCT) testing the efficacy of metformin compared with placebo, usual care or other interventions in pregnant women. Two independent reviewers will assess eligibility using prespecified criteria and will conduct data extraction and quality appraisal of eligible studies. Authors of included trials will be contacted and asked to contribute IPD. Primary outcomes include maternal glycaemic parameters and GDM, as well as neonatal hypoglycaemia, anthropometry and gestational age at delivery. Other adverse maternal, birth and neonatal outcomes will be assessed as secondary outcomes. IPD from these RCTs will be harmonised and a two-step meta-analytic approach will be used to determine the efficacy and safety of metformin in pregnancy, with a priori adjustment for covariates and subgroups to examine effect moderators of treatment outcomes. Sensitivity analyses will assess heterogeneity, risk of bias and the impact of trials which have not provided IPD.

ETHICS AND DISSEMINATION

All IPD will be deidentified and studies contributing IPD will have ethical approval from their respective local ethics committees. This study will provide robust evidence regarding the efficacy and safety of metformin use in pregnancy, and may identify subgroups of patients who may benefit most from this treatment modality. Findings will be published in peer-reviewed journals and disseminated at scientific meetings, providing much needed evidence to inform clinical and public health actions in this area.

Pharmacologic Treatment of Diabetes in Pregnancy

Importance

Diabetes affects 6% to 9% of pregnancies, with gestational diabetes mellitus accounting for more than 90% of cases. Pregestational and gestational diabetes are associated with significant maternal and fetal risks; therefore, screening and treatment during pregnancy are recommended. Recommendations regarding the preferred treatment of diabetes in pregnancy have recently changed, with slight differences between American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) recommendations.

Objective

Our review discusses the diagnosis, management, and treatment of pregestational and gestational diabetes with the oral hypoglycemic agents metformin and glyburide as well as insulin. We also review the evidence for the safety and efficacy of these medications in pregnancy.

Evidence Acquisition

Articles were obtained from PubMed, the ACOG Practice Bulletin on Gestational Diabetes Mellitus, and the SMFM statement on the pharmacological treatment of gestational diabetes.

Results

Insulin does not cross the placenta and has an established safety profile in pregnancy and is therefore considered a first-line treatment for gestational diabetes. Metformin and glyburide have also been shown to be relatively safe in pregnancy but with more limited long-term data. Regarding maternal and fetal outcomes, metformin is superior to glyburide and similar to insulin.

Conclusions and Relevance

Insulin is the preferred pharmacologic treatment according to ACOG. However, SMFM has stated that outcomes with metformin are similar, and it may also be considered as first-line therapy. Both agree that the available data show that metformin is safer and superior to glyburide, and glyburide is no longer recommended as a first-line therapy for the treatment of gestational diabetes.

Neonatal outcomes and its association among gestational diabetes mellitus with and without depression, anxiety and stress symptoms in Malaysia: A cross-sectional study

OBJECTIVE

Prevalence of depression, anxiety and stress symptoms in gestational diabetes mellitus ranges from 10.2% to 39.9% based on previous studies in Malaysia. Presence of depression, anxiety or stress in pregnancy may increase the risk of neonatal morbidity and mortality. The aim of this study was to determine the prevalence of neonatal outcomes and its association among mothers with gestational diabetes mellitus with and without the presence of depression, anxiety and stress symptoms in Malaysia.

DESIGN

This was a cross-sectional study.

SETTING

Tertiary hospitals in Malaysia.

PARTICIPANTS

Mothers with gestational diabetes mellitus (n = 418) who deliver their neonates at two major tertiary hospitals in Malaysia.

MEASUREMENTS

Neonatal outcomes, such as low birth weight, preterm birth, macrosomia, metabolic and electrolyte disorders, neonatal respiratory distress and congenital anomalies were determined.

FINDINGS

Prevalence of low birth weight in neonates born to mothers with gestational diabetes mellitus was 14.6%, followed by metabolic and electrolyte disorders 10.5%, preterm birth 9.1%, macrosomia 4.8%, neonatal respiratory distress 5.8% and congenital anomalies (2.4%). Among the adverse neonatal outcomes, neonatal respiratory distress was significantly associated with the presence of depression symptoms in mothers with gestational diabetes mellitus using univariate analysis (p = 0.010). After controlling for confounding factors, predictors for neonatal respiratory distress at delivery were the presence of depression symptoms in mothers with gestational diabetes mellitus (Adjusted OR = 3.87, 95% CI = 1.32-11.35), living without a husband (Adjusted OR = 9.74, 95% CI = 2.04-46.51), preterm delivery (Adjusted OR = 7.20, 95% CI = 2.23-23.30), caesarean section (Adjusted OR = 3.33, 95% CI = 1.09-10.15), being nulliparous and primiparous (Adjusted OR = 3.62, 95% CI = 1.17-11.17) and having family history of diabetes (Adjusted OR = 3.20, 95% CI = 1.11-9.21).

KEY CONCLUSIONS

The findings of this study demonstrate the positive association of neonatal respiratory distress with the presence of depression symptoms in mothers with gestational diabetes mellitus.

IMPLICATIONS FOR PRACTICE

It is therefore important to identify depression symptoms after a diagnosis of gestational diabetes mellitus in pregnant mothers is made to enable early referral and interventions.

Comparative effects of glibenclamide, metformin and insulin on fetal pancreatic histology and maternal blood glucose in pregnant streptozotocin-induced diabetic rats

BACKGROUND

Oral hypoglycemic agents use during pregnancy was assumed to cause fetal macrosomia and skeletal deformities, and maternal complications due to significant transfer across placenta or ineffective control of blood glucose.

OBJECTIVE

This study investigated effects of insulin, metformin and glibenclamide on maternal blood glucose; and fetal crown-rump length, gross malformation and pancreatic histology in pregnant streptozotocin-induced diabetic rats.

METHODS

Twenty-five pregnant rats of groups 1 to 5 as normal and diabetic controls; and diabetic treated with insulin, metformin and glibenclamide were used. Experimental GDM was induced using 45 and 35mg/Kgbw of intraperitoneal streptozotocin.

RESULTS

Metformin, Insulin and Glibenclamide significantly reduced maternal glucose by 140.6mg/dL, 103.2mg/dL and 98.54mg/dl; respectively and showed islets with regular interlobular ducts, islets with some irregular interlobular ducts, and islets with many irregular interlobular ducts in histological fetal pancreatic photomicrographs respectively. This depicts metformin having highest ameliorative effect. There were no significant differences in maternal and fetal body weights, maternal blood glucose between diabetic groups, and fetal gross examination.

CONCLUSION

At the doses used in this research, metformin and glibenclamide showed no adverse effects on maternal and fetal features in the treatment of GDM. Thus, they can be used as safe and inexpensive alternatives to insulin.

Prevalence and profile of adverse drug reactions in high-risk pregnancy: a cohort study

Background

Commonly used drugs in pregnant women include antihypertensives, hypoglycemic agents, analgesics, antimicrobials, antiemetics and antispasmodics but the use of medicines during pregnancy, especially in high-risk pregnancy, may be associated with high risk of adverse drug reactions (ADR). The objective of this study was to determine the risk of an adverse drug reaction in hospitalized high-risk pregnant women and the factors associated with their occurrence.

Methods

The study received IRB approval and all patients gave written informed consent. Observational cohort study conducted from September 2015 to November 2016 in 1070 pregnant women consecutively admitted to the high risk sector of the University Maternity Januário Cicco in Brazil. ADR were detected through daily active search. Risk factors for the occurrence of ADR were determined using multivariate logistic regression.

Results

The mean age of the study population was 26.2 ± 7.2 years and gestational age was 31.2 ± 7.2 weeks. The average number of previous pregnancies was 2.4 ± 1.8 and 46.4% reported cases of previous abortion/miscarriage. ADR were observed in 10.7% of women. The main medicines involved, with the incidence rate of ADR per 100 prescriptions of the drug (IR), were parenteral scopolamine (IR 14.9%), methyldopa (IR 15.9%), insulin (IR 8.46%), oral scopolamine (IR 3.58%), captopril (IR 2.38%) and ceftriaxone (IR 18.4%). Multivariate analysis showed that only gestational age in weeks (odds-ratio 0.97, 95% confidence interval 0.95–0.98) was related to the occurrence of adverse reactions.

Conclusion

Lower gestational age is a risk factor for high-risk pregnant women, increasing the likelihood of adverse reactions, with parenteral medications being those that have the highest potential risk of harm.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2321-8) contains supplementary material, which is available to authorized users.

Drugs to Control Diabetes During Pregnancy

Diabetes is a common complication of pregnancy associated with both short- and long-term adverse maternal and offspring effects. All types of diabetes in pregnancy are increasing in prevalence. Treatment of diabetes in pregnancy, targeting glycemic control, improves both maternal and offspring outcomes, albeit imperfectly for many women. Pharmacologic treatment recommendations differ between pregestational and gestational diabetes. Improved treatment of diabetes in pregnancy will need to consider maternal disease heterogeneity and comorbidities as well as long-term offspring outcomes. In this review, the authors summarize recent clinical studies to highlight established pharmacologic treatments for diabetes in pregnancy and provide suggestions for further research.

Longer-term outcomes in offspring of GDM mothers treated with metformin versus insulin

Insulin has traditionally been the gold standard pharmacological treatment for gestational diabetes mellitus (GDM). Insulin requires multiple injections a day, can cause frequent hypoglycaemia, requires careful handling, and is generally more expensive compared to oral agents. Metformin has been increasingly popular in recent years. Based on the short-term data available, metformin appears to be safe and effective for the treatment of GDM but existing studies have all stressed the lack of longer-term offspring data. This article will analyse the evidence available on the longer-term outcomes in the offspring of women with GDM treated with metformin versus insulin. Pubmed, EMBASE, CENTRAL, and CNKI were searched for follow-up studies of randomised controlled trials that compared metformin with insulin for the treatment of GDM. Existing follow-up studies did not find any significant increase in the risk of adverse effects in terms of growth and development in the offspring of GDM mothers managed with metformin versus insulin.

Pregestational Diabetes in Pregnancy

Diabetes is a common chronic condition in women of reproductive age. Preconception care is crucial to reducing the risk of adverse maternal and fetal outcomes, such as hypertensive disorders, abnormal fetal growth, traumatic delivery and stillbirth, associated with poor glycemic control. Insulin is the preferred medication to optimize glucose control in women with pregestational diabetes. Frequent dose adjustments are needed during pregnancy to achieve glycemic goals, and team-based multidisciplinary care may help. Postpartum care should include lactation support, counseling on contraceptive options, and transition to primary care.

Safety of non-insulin glucose-lowering drugs in pregnant women with pre-gestational diabetes: A cohort study

AIMS

To evaluate the association between use of non-insulin antidiabetics in early pregnancy and the risk of miscarriages, stillbirths and major structural malformations.

MATERIALS AND METHODS

A cohort of 1511 pregnant women with pre-gestational diabetes linked to live births was identified using electronic medical records from The Health Improvement Network (THIN) for the period 1995 to 2012. Information on prescriptions, foetal outcomes and potential confounders was ascertained from both codes and free text in the THIN database. Odds ratios (OR) and 95% confidence intervals (CI) of adverse foetal outcomes in women treated with non-insulin antidiabetics during the first trimester compared to those on insulin were estimated using logistic regression to adjust for type of diabetes, glycaemic control and other maternal characteristics.

RESULTS

Among 311 pregnant women on non-insulin antidiabetics, 21.9% had a miscarriage and 1.6% a stillbirth; 1.9% of live births had major malformations. The corresponding frequencies for the 883 women on insulin were 13.3%, 1.7% and 9.6%. Insulin users more often had type 1 diabetes and poor glycaemic control. Compared to women with type 1 diabetes, those with type 2 diabetes had a higher risk of miscarriages (20.5% vs 12.8%) but a lower prevalence of malformations (4.0% vs 9.2%). Compared to women with HbA1c ≤7%, those with HbA1c >7% had a higher prevalence of malformations (12.6% vs 2.7%). After adjustment for diabetes type and glycaemic control, compared to insulin, non-insulin antidiabetic patients were associated with an OR for miscarriage of 1.19 (95% CI, 0.75-1.89), for stillbirths of 0.65 (95% CI, 0.16-2.58), and for major malformations of 0.25 (95% CI, 0.08-0.84).

CONCLUSION

Among women with diabetes, use of non-insulin antidiabetics early in pregnancy was not associated with greater risks of foetal losses or major malformations than was insulin.

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.

Metformin in the first trimester and risks for specific birth defects in the National Birth Defects Prevention Study

BACKGROUND

We assessed associations between first-trimester metformin use for pregestational diabetes and specific major birth defects.

METHODS

We compared risks associated with first-trimester metformin use by diabetic women to nondiabetic women on no diabetes medication; we calculated crude odds ratios by exact logistic regression and adjusted by inverse probability weighting. Confounding by diabetes was assessed by comparing risks for metformin-exposed diabetic women to those for insulin-exposed diabetics and nondiabetics treated with metformin for subfertililty.

RESULTS

Among 9,279 nonmalformed controls and 24,375 malformed cases, diabetics who used metformin (with or without insulin) had increased adjusted odds ratios (aORs) for several birth defects associated with diabetes. However, women treated with metformin for subfertility had aORs similar to or lower than those for diabetic metformin users, and many approximated the null. For atrial septal defect secundum, anorectal defects, and limb reduction defects, the estimates for metformin when used for subfertility were 2-3-fold.

CONCLUSION

While metformin use for diabetes was associated with an increased risk of many birth defects, when metformin was used for subfertility most defects had aORs that approximated the null, while only three defects had modestly increased aORs, two of which had lower confidence bounds that included the null. Our study does not suggest that metformin poses an appreciable risk for major birth defects, but further studies are necessary.

Outcomes for Women with Gestational Diabetes Treated with Metformin: A Retrospective, Case-Control Study

Metformin is increasingly being used a therapeutic option for the management of gestational diabetes mellitus (GDM). The aim of this study was to compare the maternal characteristics and perinatal outcomes of women with GDM treated with metformin (with or without supplemental insulin) with those receiving other management approaches. A retrospective, case-control study was carried out and 83 women taking metformin were matched 1:1 with women receiving insulin or diet and lifestyle modification alone. Women managed with diet and lifestyle modification had a significantly lower fasting plasma glucose (p < 0.001) and HbA1c (p < 0.01) at diagnosis of GDM. Furthermore, women managed with metformin had a higher early pregnancy body mass index (BMI) compared to those receiving insulin or diet and lifestyle modification (p < 0.001). There was no difference in mode of delivery, birth weight or incidence of large- or small-for-gestational-age neonates between groups. Women receiving glucose lowering therapies had a higher rate of neonatal hypoglycaemia (p < 0.05). The incidence of other adverse perinatal outcomes was similar between groups. Despite their greater BMI, women with metformin-treated GDM did not have an increased risk of adverse perinatal outcomes. Metformin is a useful alternative to insulin in the management of GDM.

"It's a Very Big Burden on Me": Women's Experiences Using Insulin for Gestational Diabetes

Objectives Gestational Diabetes Mellitus (GDM) affects hundreds of thousands of women each year. Many require medications to manage their blood glucose levels. Only insulin is approved by the U.S. Food and Drug Administration for use in pregnancy. While other medications can be used, their safety remains controversial. Few studies have examined women's lived experience of using insulin for GDM. Our objective in this study was to foreground the voices of women speaking about their treatment experience. Methods We conducted two focus groups including 16 women treated for GDM with medications, primarily insulin. Topics included women's experiences with GDM diagnosis and treatment including concerns about risks and benefits of treatments. Transcripts were analyzed using an inductive coding approach. Results Many women had negative experiences with insulin use, such as feeling that they had no voice in treatment decisions, and received inadequate information about insulin, including about the impact it would have on their daily lives. Many continued to have difficulty managing their blood sugar once on insulin, and they worried about the short term and long term health effects of insulin on themselves and their babies. They wanted more information about non-insulin treatment options as well as more social support. Conclusion In our sample of women with GDM, insulin treatment resulted in negative experiences with emotional and experiential impacts lasting beyond pregnancy. There is a need for more research on other medications for GDM, so that women can have access to more treatment options and better information to guide their choices.

Combining metformin and esomeprazole is additive in reducing sFlt-1 secretion and decreasing endothelial dysfunction - implications for treating preeclampsia

INTRODUCTION

The discovery of new treatments that prevent or treat preeclampsia would be a major advance. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sENG) are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. We recently identified metformin and esomeprazole as potential treatments for preeclampsia. Both reduce placental and endothelial secretion of sFlt-1 and soluble endoglin, and reduce endothelial dysfunction.

OBJECTIVES

We set out to assess whether combining metformin and esomeprazole would additively reduce sFlt-1 and soluble endoglin secretion and reduce endothelial dysfunction (verses drug alone). Metformin and esomeprazole were added to primary placental cells and tissues, and endothelial cells and their effects on sFlt-1 and soluble endoglin secretion were assessed in vitro. Tumor necrosis factor-α (TNF-α) was added to endothelial cells to induce dysfunction in vitro. We examined the ability of metformin + esomeprazole to rescue TNF-α induced vascular cell adhesion molecule-1 (VCAM-1) and Endothelin-1 (ET-1) expression, leukocyte adhesion (markers of endothelial dysfunction).

RESULTS

Combining metformin and esomeprazole was additive at reducing sFlt-1 secretion and expression of sFlt-1 e15a mRNA isoform in primary cytotrophoblast, placental explants and endothelial cells. In contrast, no additive reduction in sENG was observed with combined metformin and esomeprazole. The low-dose combination of metformin + esomeprazole additively reduced TNF-α-induced VCAM-1 mRNA, but not VCAM-1 protein expression. There was no additive reduction when combining metformin and esomeprazole on TNF-α induced PBMC adhesion to endothelial cells. However, combining metformin and esomeprazole additively reduced ET-1 mRNA expression.

CONCLUSIONS

In conclusion combining metformin and esomeprazole additively reduced secretion of sFlt-1, and markers of endothelial dysfunction. The combination of metformin and esomeprazole may provide a more effective treatment or prevention for preeclampsia compared to either as single agents.

Rahim AA, Eliana F, Shrestha HK, Chaudhary S, Ngugi N, Mbanya JC, Aye TT, Latt TS, Akanov ZA, Syed AR, Tandon N, Unnikrishnan AG, Madhu SV, Jawa A, Chowdhury S, Bajaj S, Das AK. Consensus Recommendations on Sulfonylurea and Sulfonylurea Combinations in the Management of Type 2 Diabetes Mellitus - International Task Force

For decades, sulfonylureas (SUs) have been important drugs in the antidiabetic therapeutic armamentarium. They have been used as monotherapy as well as combination therapy. Focus on newer drugs and concerns about the risk of severe hypoglycemia and weight gain with some SUs have led to discussion on their safety and utility. It has to be borne in mind that the adverse events associated with SUs should not be ascribed to the whole class, as many modern SUs, such as glimepiride and gliclazide modified release, are associated with better safety profiles. Furthermore, individualization of treatment, using SUs in combination with other drugs, backed with careful monitoring and patient education, ensures maximum benefits with minimal side effects. The current guidelines, developed by experts from Africa, Asia, and the Middle East, promote the safe and smart use of SUs in combination with other glucose-lowering drugs.

Gestational diabetes from A to Z

Gestational diabetes mellitus (GDM) is defined as any degree of hyperglycaemia that is recognized for the first time during pregnancy. This definition includes cases of undiagnosed type 2 diabetes mellitus (T2DM) identified early in pregnancy and true GDM which develops later. GDM constitutes a greater impact on diabetes epidemic as it carries a major risk of developing T2DM to the mother and foetus later in life. In addition, GDM has also been linked with cardiometabolic risk factors such as lipid abnormalities, hypertensive disorders and hyperinsulinemia. These might result in later development of cardiovascular disease and metabolic syndrome. The understanding of the different risk factors, the pathophysiological mechanisms and the genetic factors of GDM, will help us to identify the women at risk, to develop effective preventive measures and to provide adequate management of the disease. Clinical trials have shown that T2DM can be prevented in women with prior GDM, by intensive lifestyle modification and by using pioglitazone and metformin. However, a matter of controversy surrounding both screening and management of GDM continues to emerge, despite several recent well-designed clinical trials tackling these issues. The aim of this manuscript is to critically review GDM in a detailed and comprehensive manner, in order to provide a scientific analysis and updated write-up of different related aspects.

Glibenclamide and metfoRmin versus stAndard care in gEstational diabeteS (GRACES): a feasibility open label randomised trial

BACKGROUND

Metformin is widely used to treat gestational diabetes (GDM), but many women remain hyperglycaemic and require additional therapy. We aimed to determine recruitment rate and participant throughput in a randomised trial of glibenclamide compared with standard therapy insulin (added to maximum tolerated metformin) for treatment of GDM.

METHODS

We conducted an open label feasibility study in 5 UK antenatal clinics among pregnant women 16 to 36 weeks' gestation with metformin-treated GDM. Women failing to achieve adequate glycaemic control on metformin monotherapy were randomised to additional glibenclamide or insulin. The primary outcome was recruitment rate. We explored feasibility with uptake, retention, adherence, safety, glycaemic control, participant satisfaction and clinical outcomes.

RESULTS

Records of 197 women were screened and 23 women randomised to metformin and glibenclamide (n = 13) or metformin and insulin (n = 10). Mean (SD) recruitment rate was 0.39 (0.62) women/centre/month. 9/13 (69.2%, 95%CI 38.6-90.9%) women adhered to glibenclamide and all provided outcome data (100% retention). There were no episodes of severe hypoglycaemia, but metformin and insulin gave superior glycaemic control to metformin and glibenclamide, with fewer blood glucose readings <3.5 mmol/l (median [IQR] difference/woman/week of treatment 0.58 [0.03-1.87]).

CONCLUSIONS

A large randomised controlled trial comparing glibenclamide or insulin in combination with metformin for women with GDM would be feasible but is unlikely to be worthwhile, given the poorer glycaemic control with glibenclamide and metformin in this pilot study. The combination of metformin and glibenclamide should be reserved for women with GDM with true needle phobia or inability to use insulin therapy.

TRIAL REGISTRATION

www.clinicaltrials.gov registration number:NCT02080377 February 11th 2014.

Gestational diabetes mellitus: an updated overview

The clinical and public health relevance of gestational diabetes mellitus (GDM) is widely debated due to its increasing incidence, the resulting negative economic impact, and the potential for severe GDM-related pregnancy complications. Also, effective prevention strategies in this area are still lacking, and controversies exist regarding diagnosis and management of this form of diabetes. Different diagnostic criteria are currently adopted worldwide, while recommendations for diet, physical activity, healthy weight, and use of oral hypoglycemic drugs are not always uniform. In the present review, we provide an update of current insights on clinical aspects of GDM, by discussing the more controversial issues.

Patterns of glucose-lowering therapies and neonatal outcomes in the treatment of gestational diabetes in Canada, 2009-2014

AIM

To examine patterns of use of different glycaemic control agents for treating gestational diabetes mellitus.

METHODS

This was a large, retrospective, population-based cohort study of pregnant women with gestational diabetes from Alberta, Canada. We linked data from the Alberta Vital Statistics - Birth database with administrative claims data. Alberta Vital Statistics - Birth data were used to identify births that occurred between 1 January 2009 and 31 December 2014. We used International Classification of Diseases version 9/10 codes to identify women with gestational diabetes, and we excluded women with pre-existing diabetes.

RESULTS

Our cohort consisted of 16 857 women with gestational diabetes, with a total of 18 761 birth events between 2009 and 2014. Over the study period, the proportion of women with gestational diabetes who were treated with glycaemic control therapies increased from 25.0% to 31.4% (P<0.0001). The number of pregnancies treated with insulin only increased (from 23.6% to 28.3%; P<0.0001), as did the number treated with metformin, +/- insulin (from 1.4% to 3.2%; P<0.0001). Rates of large-for-gestational-age infants were significantly higher among pregnancies treated with insulin only (17%) or metformin (16.5%) than among pregnancies that did not receive any pharmacological treatment (12.8%).

CONCLUSIONS

Our findings show increasing use of insulin and metformin in women with gestational diabetes. Rates of large-for-gestational-age infants were similar among pregnant women receiving either pharmacological treatment, and higher than among pregnant women who did not receive any pharmacological treatment. Future research should explore the long-term outcomes and safety of metformin as an alternative for treating gestational diabetes.

Comparison of glyburide and insulin in the management of gestational diabetes: A meta-analysis

Objective

The aim of this meta-analysis was to determine the efficacy and safety of glyburide as a treatment for gestational diabetes mellitus (GDM) compared to insulin.

Methods

A meta-analysis was conducted to compare the management of gestational diabetes with glyburide and insulin. Studies fulfilling all of the following inclusion criteria were included in this meta-analysis: subjects were women with gestational diabetes requiring drug treatment; the comparison treatment included glyburide vs insulin; one or more outcomes (maternal or neonatal) should be provided in the individual study; the study design should be a randomized control trial. Exclusion criteria: non-RCT studies; non-human data. PubMed, Embase and CENTRAL databases were searched from inception until 10 October 2016.

Results

Ten randomized control trials involving 1194 participants met the inclusion criteria and were included. 13 primary outcomes (6 maternal, 7 neonatal) and 26 secondary outcomes (9 maternal, 17 neonatal) were detected and analyzed in this study. Glyburide significantly increased the risk of any neonatal hypoglycemia [risk ratio (RR), 1.89; 95% confidence interval (95%CI), 1.26 to 2.82; p = 0.002]. Sensitivity analysis confirmed robustness of this result [RR, 2.29; 95%CI, 1.49 to 3.54; p = 0.0002]. No differences were observed between the two groups with respect to birth weights [mean difference (MD), 79; 95%CI, -64 to 221.99; p = 0.28] and the risk of macrosomia [RR, 1.69; 95%CI, 0.57 to 5.08; p = 0.35].

Conclusion

For women with gestational diabetes, no differences in maternal short term outcomes were observed in those treated with glyburide or insulin. However, the incidence of neonatal hypoglycemia was higher in the glyburide group compared to the insulin group.

Efficacy of metformin in improving glycaemic control & perinatal outcome in gestational diabetes mellitus: A non-randomized study

BACKGROUND & OBJECTIVES

Gestational diabetes mellitus (GDM) can cause adverse perinatal outcome if not treated. Although insulin therapy has been the main treatment modality over decades but considering its cost and parenteral mode of administration, it does not seem to be appropriate, especially in low-resource settings. The objective of this study was to evaluate the role of metformin in GDM and know its efficacy as well as adverse effect on foetus and mother.

METHODS

All pregnant women with GDM who were not controlled on medical nutrition therapy and required metformin therapy were included in the study. Careful monitoring of blood sugar was done. Development of any maternal or foetal complications and adverse effect were recorded.

RESULTS

A total of 2797 pregnant women were screened, of whom 233 (8.3%) were found to have GDM. Of the 64 women with GDM (28.7%) who required metformin therapy, majority (93.8%) achieved blood sugar control, whereas three (4.7%) women failed. Caesarean section rate was 54 per cent, and 15.6 per cent neonates were large for gestational age. Only two (3.1%) women had gastrointestinal side effects which were minor and got resolved with time. No case of hypoglycaemia or perinatal mortality was reported.

INTERPRETATION & CONCLUSIONS

Our findings indicate that metformin may be used as a safe and effective oral hypoglycaemic agent in GDM, especially in low-resource settings where cost, storage and compliance are logistic issues. However, long-term follow up studies are needed to solve issues related to its safety in pregnancy.

Glyburide Versus Metformin and Their Combination for the Treatment of Gestational Diabetes Mellitus: A Randomized Controlled Study

OBJECTIVE

To compare the efficacy and safety of glyburide versus metformin and their combination for the treatment of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

In this prospective randomized controlled study, we randomly assigned patients with GDM at 13-33 weeks gestation and whose blood glucose was poorly controlled by diet to receive either glyburide or metformin. If optimal glycemic control was not achieved, the other drug was added. If adverse effects occurred, the drug was replaced. If both failed, insulin was given. The primary outcomes were the rate of treatment failure and glycemic control after the first-line medication according to mean daily glucose charts.

RESULTS

Glyburide was started in 53 patients and metformin in 51. In the glyburide group, the drug failed in 18 (34%) patients due to adverse effects (hypoglycemia) in 6 (11%) and lack of glycemic control in 12 (23%). In the metformin group, the drug failed in 15 (29%) patients, due to adverse effects (gastrointestinal) in 1 (2%) and lack of glycemic control in 14 (28%). Treatment success after second-line therapy was higher in the metformin group than in the glyburide group (13 of 15 [87%] vs. 9 of 18 [50%], respectively; P = 0.03). In the glyburide group, nine (17%) patients were eventually treated with insulin compared with two (4%) in the metformin group (P = 0.03). The combination of the drugs reduced the need for insulin from 33 (32%) to 11 (11%) patients (P = 0.0002). Mean daily blood glucose and other obstetrical and neonatal outcomes were comparable between groups, including macrosomia, neonatal hypoglycemia, and electrolyte imbalance.

CONCLUSIONS

Glyburide and metformin are comparable oral treatments for GDM regarding glucose control and adverse effects. Their combination demonstrates a high efficacy rate with a significantly reduced need for insulin, with a possible advantage for metformin over glyburide as first-line therapy.

Pharmacological Management of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common morbidities complicating pregnancy, with short- and long-term consequences to the mothers, fetuses, and newborns. Management and treatment are aimed to achieve best possible glycemic control, while avoiding hypoglycemia and ensuring maternal and fetal safety. It involves behavioral modifications, nutrition and medications, if needed; concurrent with maternal and fetal surveillance for possible adverse outcomes. This review aims to elaborate on the pharmacological options for GDM therapy. We performed an extensive literature review of different available studies, published during the last 50 years, concerning pharmacological therapy for GDM, dealing with safety and efficacy, for both fetal and maternal morbidity consequences; as well as failure and success in establishing appropriate metabolic and glucose control. Oral medication therapy is a safe and effective treatment modality for GDM and in some circumstances may serve as first-line therapy when nutritional modifications fail. When oral agents fail to establish glucose control then insulin injections should be added. Determining the best oral therapy in inconclusive, although it seems that metformin is slightly superior to glyburide, in some aspects. As for parenteral therapy, all insulins listed in this article are considered both safe and effective for treatment of hyperglycemia during pregnancy. Importantly, a better safety profile, with similar efficacy is documented for most analogues. As GDM prevalence rises, there is a need for successful monitoring and treatment for patients. Caregivers should know the possible and available therapeutic options.

Neurodevelopmental outcome at 2 years in offspring of women randomised to metformin or insulin treatment for gestational diabetes

OBJECTIVE

Gestational diabetes mellitus (GDM) is a common complication of pregnancy and is increasingly being treated with metformin that crosses the placenta rather than insulin, which does not. This study seeks to examine the neurodevelopment of offspring of women treated with metformin or insulin for GDM.

DESIGN

We performed a prospective follow-up study of children whose mothers had been randomly assigned at 20-33 weeks gestation to treatment with metformin or insulin for GDM. Of the 211 children followed up at 2 years, 128 were from Auckland, New Zealand (64 metformin vs 64 insulin), and 83 from Adelaide, Australia (39 metformin vs 49 insulin). Neurodevelopment was examined with the Bayley Scales of Infant Development V.2 mental development index (MDI) and psychomotor development index (PDI). Clinical and demographic background characteristics were obtained at enrolment, birth and follow-up.

RESULTS

No significant differences were found between treatment groups in clinical or demographic characteristics. The MDI and PDI composite scores were tested with general linear models. No significant differences were found between metformin and insulin, respectively, in New Zealand (MDI, M=83.6 vs 86.9 and PDI, M=83.4 vs M=85.2) or Australia (MDI, M=102.5 vs M=98.4 and PDI, M=105.6 vs M=99.9) and no interactions observed. The differences in neurodevelopmental outcomes between the Auckland and Adelaide cohorts were explained by parental ethnicity, infant birth weight >4000 g, neonatal hypoglycaemia, maternal glycaemia and smoking in the household.

CONCLUSIONS

This study provides additional data supporting the safety of metformin in the treatment of GDM.

TRIAL REGISTRATION NUMBER

ACTRN 12605000311651.

Is it worth treating gestational diabetes: if so, when and how?

The primary aims of the treatment of gestational diabetes (GDM) are to prevent macrosomia and pregnancy complications. Many large studies and meta-analyses have demonstrated that, compared with usual care, the specific treatment of women with GDM seems to achieve these aims, including lower birthweight and lower rates of shoulder dystocia. Nutritional therapy is a cornerstone of GDM care and is generally recommended as a primary treatment. Medical treatment should be started after 1-2 weeks if normoglycaemia is not achieved with lifestyle changes. This review provides an overview of the current data on and practices for the treatment of GDM and summarises a presentation given at the 'Gestational diabetes: what's up?' symposium at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Peter Damm and Colleagues, DOI: 10.1007/s00125-016-3985-5 , and by Cuilin Zhang and colleagues, DOI: 10.1007/s00125-016-3979-3 ) and an overview by the Session Chair, Kerstin Berntorp (DOI: 10.1007/s00125-016-3975-7 ).

Comparison of Glibenclamide and Insulin on Neonatal Outcomes in Pregnant Women with Gestational Diabetes

BACKGROUND

Untreated or poorly controlled gestational diabetes can cause serious complications for mother and newborn. Glibenclamide is rarely used in treating mothers with this disease. This study aimed at comparing the effect of glibenclamide and insulin on neonatal outcomes in women with gestational diabetes mellitus.

METHODS

In this randomized controlled clinical trial, 249 pregnant women aged 18-45 years within the 11(th)-33(rd) weeks of gestation with gestational diabetes, single fetus pregnancy, and in need of hyperglycemia treatment were entered and grouped randomly as either glibenclamide or insulin. In the insulin group (n = 129), insulin was administered with an initial dose of 0.2 IU/kg subcutaneously twice per day, whereas in the glibenclamide group (n = 120), 1.25 mg oral glibenclamide was administered once daily and increased if needed.

RESULTS

The results showed no significant difference in means age, gestational age, and body mass index between women in the two groups. In addition, there were no significant differences in the frequency of neonatal hypoglycemia, anomaly, hyperbilirubinemia, admission in Neonatal Intensive Care Unit (NICU), and neonatal respiratory distress between two groups. Macrosomia was lower in the glibenclamide group than the insulin group (3.3% vs. 13.2%, respectively, P = 0.005). Regression logistics model results showed that the type of treatment (odds ratio [OR]: 4.62; confidence interval [CI]: 1.45-14.02; P = 0.01) and gestational age at delivery (OR: 1.41; CI: 1.04-1.74; P = 0.01) were as predictor factors of macrosomia.

CONCLUSIONS

The results of this study revealed that glibenclamide is able to reduce the risk of fetal macrosomia without increasing neonatal anomalies, jaundice, hypocalcemia, infant respiratory distress, and NICU admission.

Use of metformin earlier in pregnancy predicts supplemental insulin therapy in women with gestational diabetes

The use of metformin in gestational diabetes is safe and effective, yet some women require additional insulin therapy to achieve glycaemic targets. We found a significant association between earlier gestational age at initiation of metformin therapy and the necessity for supplemental insulin in women treated with metformin during pregnancy.

Efficacy and safety of metformin for the treatment of gestational diabetes: a new approach to the problem

Historically, the following two methods were used to treat gestational diabetes mellitus: non-medical life-style interventions (diet and increased physical activity) and insulin treatment when other interventions were not effective. The possibility of alternative types of treatment such as oral anti-diabetic drugs has been the source of debate in recent years. Metformin is an oral anti-diabetic drug that reduces insulin resistance, which is common during gestation and is considered one of the main pathways of glucose metabolism alteration during pregnancy. The main concern is that metformin can cross the placenta and is found unchanged in foetal blood. This is the reason why oral anti-diabetic drugs are contraindicated during pregnancy in many countries, including Russia (according to the 2012 Russian recommendations for gestational diabetes treatment). In recent years, many studies investigating the safety and efficacy of metformin for maternal and foetal health have been published. We will review recent randomized clinical trials and discuss new international clinical recommendations (FIGO, 2015) and new opportunities for gestational diabetes mellitus treatment. 

Metformin as a prevention and treatment for preeclampsia: effects on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion and endothelial dysfunction

BACKGROUND

Preeclampsia is associated with placental ischemia/hypoxia and secretion of soluble fms-like tyrosine kinase 1 and soluble endoglin into the maternal circulation. This causes widespread endothelial dysfunction that manifests clinically as hypertension and multisystem organ injury. Recently, small molecule inhibitors of hypoxic inducible factor 1α have been found to reduce soluble fms-like tyrosine kinase 1 and soluble endoglin secretion. However, their safety profile in pregnancy is unknown. Metformin is safe in pregnancy and is also reported to inhibit hypoxic inducible factor 1α by reducing mitochondrial electron transport chain activity.

OBJECTIVE

The purposes of this study were to determine (1) the effects of metformin on placental soluble fms-like tyrosine kinase 1 and soluble endoglin secretion, (2) to investigate whether the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion are regulated through the mitochondrial electron transport chain, and (3) to examine its effects on endothelial dysfunction, maternal blood vessel vasodilation, and angiogenesis.

STUDY DESIGN

We performed functional (in vitro and ex vivo) experiments using primary human tissues to examine the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion from placenta, endothelial cells, and placental villous explants. We used succinate, mitochondrial complex II substrate, to examine whether the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin secretion were mediated through the mitochondria. We also isolated mitochondria from preterm preeclamptic placentas and gestationally matched control subjects and measured mitochondrial electron transport chain activity using kinetic spectrophotometric assays. Endothelial cells or whole maternal vessels were incubated with metformin to determine whether it rescued endothelial dysfunction induced by either tumor necrosis factor-α (to endothelial cells) or placenta villous explant-conditioned media (to whole vessels). Finally, we examined the effects of metformin on angiogenesis on maternal omental vessel explants.

RESULTS

Metformin reduced soluble fms-like tyrosine kinase 1 and soluble endoglin secretion from primary endothelial cells, villous cytotrophoblast cells, and preterm preeclamptic placental villous explants. The reduction in soluble fms-like tyrosine kinase 1 and soluble endoglin secretion was rescued by coadministration of succinate, which suggests that the effects of metformin on soluble fms-like tyrosine kinase 1 and soluble endoglin were likely to be regulated at the level of the mitochondria. In addition, the mitochondrial electron transport chain inhibitors rotenone and antimycin reduced soluble fms-like tyrosine kinase 1 secretion, which further suggests that soluble fms-like tyrosine kinase 1 secretion is regulated through the mitochondria. Mitochondrial electron transport chain activity in preterm preeclamptic placentas was increased compared with gestation-matched control subjects. Metformin improved features of endothelial dysfunction relevant to preeclampsia. It reduced endothelial cell messenger RNA expression of vascular cell adhesion molecule 1 that was induced by tumor necrosis factor-α (vascular cell adhesion molecule 1 is an inflammatory adhesion molecule up-regulated with endothelial dysfunction and is increased in preeclampsia). Placental conditioned media impaired bradykinin-induced vasodilation; this effect was reversed by metformin. Metformin also improved whole blood vessel angiogenesis impaired by fms-like tyrosine kinase 1.

CONCLUSION

Metformin reduced soluble fms-like tyrosine kinase 1 and soluble endoglin secretion from primary human tissues, possibly by inhibiting the mitochondrial electron transport chain. The activity of the mitochondrial electron transport chain was increased in preterm preeclamptic placenta. Metformin reduced endothelial dysfunction, enhanced vasodilation in omental arteries, and induced angiogenesis. Metformin has potential to prevent or treat preeclampsia.

Metformin for the treatment of gestational diabetes: An updated meta-analysis

OBJECTIVE

To assess the efficacy of metformin and insulin in the treatment of pregnant women with gestational diabetes mellitus (GDM).

METHODS

A meta-analysis was conducted by including randomized controlled trials comparing metformin and insulin in GDM. An electronic search was conducted to identify relevant studies. Data were synthesized by a random effects meta-analysis model. A Bayesian analysis was also performed to account for uncertainties in the treatment efficacy.

RESULTS

Eight clinical trials involving 1712 individuals were included in the final analysis. The pooled estimates of metformin-insulin differences were very small and statistically non-significant in fasting plasma glucose, postprandial plasma glucose and HbA1c, measured at 36-37 weeks of gestation. Notably, 14-46% of those receiving metformin required additional insulin. Compared with the insulin group, metformin treatment was associated with a lower incidence of neonatal hypoglycemia (relative risk, RR 0.74; 95% CI 0.58-0.93; P=0.01) and of neonatal intensive care admission (RR 0.76; 95% CI 0.59-0.97; P=0.03). Bayesian analysis revealed that the efficacy of metformin was consistently higher than insulin with a probability of over 98% on these two neonatal complications. Other outcomes were not significantly different between the two treatment groups.

CONCLUSION

In women with gestational diabetes, metformin use and insulin therapy have comparable glycemic control profile, but metformin use was associated with lower risk of neonatal hypoglycemia.

Oral hypoglycemic agents: do the ends justify the means?

BACKGROUND

Glyburide has replaced insulin as the first line of therapy in the treatment of gestational diabetes in the United States. Glyburide and metformin therapies were reported to be comparable to insulin yet also cost-effective, patient-friendly, and potentially compliance-enhancing. Recently, the efficacy of the use of these oral hypoglycemic drugs has been questioned. In this review, the questionable concerns will be addressed: Which diabetic drug(s) cross the placenta? What is the quality of evidence and the data source validity? Which treatment modalities are most effective in reducing the primary outcome in GDM? Which drug is most effective in improving secondary outcomes?

FINDINGS

This review documents the methodological issues in study design that have impacted the results for the provision of health care interventions in GDM. The review summarizes the contents of the articles qualitatively and assesses the theoretical and empirical evidence. Multiple types of studies exist and every study design serves a specific purpose. Different study designs addressing the same question can yield varying results. The risk of presenting uncertain results without categorically knowing the direction and magnitude of the effect holds true for both randomized and nonrandomized controlled trials. The review further emphasizes the importance of achieving the targeted levels of glycemic control.

CONCLUSION

The implications of this review are critical to addressing the current gaps in the literature on the efficacy of the use of oral hypoglycemic agents in GDM. The emphasis needs to be placed on patient treatment in order to manage hyperglycemia to reduce fetal and maternal morbidity. In this regard, we need to delineate proper outcome criteria that will reflect disease severity and treat using appropriate pharmacological therapy.

Gestational diabetes: A clinical update

Gestational diabetes mellitus (GDM) is increasing in prevalence in tandem with the dramatic increase in the prevalence of overweight and obesity in women of childbearing age. Much controversy surrounds the diagnosis and management of gestational diabetes, emphasizing the importance and relevance of clarity and consensus. If newly proposed criteria are adopted universally a significantly growing number of women will be diagnosed as having GDM, implying new therapeutic challenges to avoid foetal and maternal complications related to the hyperglycemia of gestational diabetes. This review provides an overview of clinical issues related to GDM, including the challenges of screening and diagnosis, the pathophysiology behind GDM, the treatment and prevention of GDM and the long and short term consequences of gestational diabetes for both mother and offspring.

Metformin versus Insulin in the Management of Pre-Gestational Diabetes Mellitus in Pregnancy and Gestational Diabetes Mellitus at the Korle Bu Teaching Hospital: A Randomized Clinical Trial

Objective

To determine if metformin monotherapy or metformin in combination with insulin is equally effective as insulin monotherapy at glycemic control in diabetes mellitus in pregnancy among Ghanaians.

Methods

This was a study involving 104 pregnant women with type 2 diabetes mellitus (T2DM) or gestational diabetes mellitus (GDM) at 20-30 weeks gestation. Participants were randomized into metformin and insulin treatment groups. Starting dose of metformin was 500 mg once a day and increased gradually over two (2) weeks, to meet glycemic targets. Insulin was added if targets could not be reached on metformin alone at maximum doses. Total daily dose of premixed insulin at initiation was calculated as 0.3 IU/kg body weight and titrated upwards to achieve glycemic control. Glycemic profile monitoring was done every two weeks.

Results

The two hour post prandial blood glucose (2HPG) levels were significantly lower in the metformin group than the insulin group (p= 0.004).

Conclusion

The findings of this study suggest that metformin monotherapy is effective in achieving glycemic targets in the management of diabetes in pregnancy. It is more effective than insulin in lowering the 2HPG level.

Trial Registration

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12614000942651