Short- and long-term outcomes of metformin compared with insulin alone in pregnancy: a systematic review and meta-analysis

Earlier detection of gestational diabetes impacts on medication requirements, neonatal and maternal outcomes

AIM

Gestational diabetes (GD) is a global health concern with significant implications for maternal and neonatal outcomes. This study investigates the association between early GD (eGD) diagnosis (<24 weeks), pharmacotherapy requirements and adverse neonatal outcomes.

MATERIALS AND METHODS

A cohort of 369 pregnant women underwent a 75-g oral glucose tolerance test. Maternal variables, pharmacotherapy prescriptions and neonatal outcomes were analysed employing t-tests, χ2 tests, and logistic regression. A p < .05 was considered significant.

RESULTS

Early GD increased the odds of neonatal hypoglycaemia [odds ratio (OR): 18.57, p = .013] and respiratory distress syndrome (OR: 4.75, p = .034). Nutritional therapy prescription by an accredited nutritionist was the most common treatment in women diagnosed after 24 weeks, but those with eGD required more frequently specialized nutritional consulting + metformin to achieve glycaemic control (p = .027). eGD was associated with a higher requirement of nutritional therapy prescription + metformin (OR: 2.26, 95% confidence interval: 1.25-4.09, p = .007) and with maternal hyperglycaemia during the post-partum period at 2 h of the oral glucose tolerance test (OR: 1.03, 95% confidence interval: 1.02-1.13, p = .024).

CONCLUSION

Timely diagnosis and personalized treatment of GD are desirable because an earlier presentation is related to a higher risk of adverse neonatal and maternal outcomes.

Neonatal outcome following metformin-treated gestational diabetes mellitus: A population-based cohort study

INTRODUCTION

Neonatal hypoglycemia is a common complication associated with gestational diabetes and therefore relevant to consider in evaluations of maternal treatment. We aimed to investigate the risk of neonatal hypoglycemia in offspring exposed to metformin treatment alone (MT) or combined with insulin (MIT) in comparison with nutrition therapy alone (NT), and insulin treatment alone (IT). In addition, we investigated MT in comparison with MIT. Secondary outcomes included neonatal anthropometrics, respiratory morbidity, hyperbilirubinemia, 5-min Apgar score, and preterm birth.

MATERIAL AND METHODS

This Swedish population-based cohort included 16 181 women diagnosed with gestational diabetes, and their singleton offspring born in 2019-2021. We estimated risk as adjusted odds ratio (aOR) with 95% confidence interval (CI), using individual-level, linkage register-data in multivariable logistic regression models.

RESULTS

In the main analysis, MT was associated with a lower risk of neonatal hypoglycemia vs NT (aOR 0.85, 95% CI: 0.74-0.96), vs MIT (0.74 [0.64-0.87]), and vs IT (0.47 [0.40-0.55]), whereas MIT was associated with a similar risk of neonatal hypoglycemia vs NT (1.14 [0.99-1.30]) and with lower risk vs IT (0.63 [0.53-0.75]). However, supplemental feeding rates were lower for NT vs pharmacological treatments (p < 0.001). In post hoc subgroup analyses including only exclusively breastfed offspring, the risk of neonatal hypoglycemia was modified and similar among MT and NT, and higher in MIT vs NT. Insulin exposure, alone or combined with metformin, was associated with increased risk of being large for gestational age. Compared with NT, exposure to any pharmacological treatment was associated with significantly lower risk of 5-min Apgar score < 4. All other secondary outcomes were comparable among the treatment categories.

CONCLUSIONS

The risk of neonatal hypoglycemia appears to be comparable among offspring exposed to single metformin treatment and nutrition therapy alone, and the lower risk that we observed in favor of metformin is probably explained by a difference in supplemental feeding practices rather than metformin per se. By contrast, the lower risk favoring metformin exposure over insulin exposure was not explained by supplemental feeding. However, further investigations are required to determine whether the difference is an effect of metformin per se or mediated by other external factors.

Fetal and post-natal outcomes in offspring after intrauterine metformin exposure: A systematic review and meta-analysis of animal experiments

AIMS

The impact of maternal metformin use during pregnancy on fetal, infant, childhood and adolescent growth, development, and health remains unclear. Our objective was to systematically review the available evidence from animal experiments on the effects of intrauterine metformin exposure on offspring's anthropometric, cardiovascular and metabolic outcomes.

METHODS

A systematic search was conducted in PUBMED and EMBASE from inception (searched on 12th April 2023). We extracted original, controlled animal studies that investigated the effects of maternal metformin use during pregnancy on offspring anthropometric, cardiovascular and metabolic measurements. Subsequently, risk of bias was assessed and meta-analyses using the standardized mean difference and a random effects model were conducted for all outcomes containing data from 3 or more studies. Subgroup analyses were planned for species, strain, sex and type of model in the case of 10 comparisons or more per subgroup.

RESULTS

We included 37 articles (n = 3133 offspring from n = 716 litters, containing n = 51 comparisons) in this review, mostly (95%) on rodent models and 5% pig models. Follow-up of offspring ranged from birth to 2 years of age. Thirty four of the included articles could be included in the meta-analysis. No significant effects in the overall meta-analysis of metformin on any of the anthropometric, cardiovascular and metabolic offspring outcome measures were identified. Between-studies heterogeneity was high, and risk of bias was unclear in most studies as a consequence of poor reporting of essential methodological details.

CONCLUSION

This systematic review was unable to establish effects of metformin treatment during pregnancy on anthropometric, cardiovascular and metabolic outcomes in non-human offspring. Heterogeneity between studies was high and reporting of methodological details often limited. This highlights a need for additional high-quality research both in humans and model systems to allow firm conclusions to be established. Future research should include focus on the effects of metformin in older offspring age groups, and on outcomes which have gone uninvestigated to date.

Challenges in Conducting Clinical Trials for Preeclampsia

PURPOSE OF REVIEW

To review recent data describing the challenges and innovations in therapeutic research focused on the prevention and treatment of preeclampsia.

RECENT FINDINGS

Pregnant individuals have traditionally been excluded from therapeutic research, resulting in a paucity of innovation in therapeutics for pregnancy-specific medical conditions, especially preeclampsia. With the increased awareness of maternal morbidity and mortality, there is significant interest among researchers to expand therapeutic research in pregnancy. Several medications, including aspirin, pravastatin, metformin, and esomeprazole, which are commonly used in non-pregnant populations, are now being investigated for preeclampsia prevention. However, given the historic precedent of exclusion, along with the regulatory, ethical, and feasibility concerns that accompany this population, the study of these and novel medications has been complicated by numerous challenges. While complex, and laden with challenges, there is great ongoing need for therapeutic research to address preeclampsia. Aspirin, pravastatin, metformin, and esomeprazole have all shown promise as potential therapeutic agents; however, their use remains to be optimized, and innovative therapeutics need to be developed.

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Position paper of the Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), and the Italian Study Group of Diabetes in pregnancy: Metformin use in pregnancy

OBJECTIVE

This document purpose is to create an evidence-based position statement on the role of metformin therapy in pregnancy complicated by obesity, gestational diabetes (GDM), type 2 diabetes mellitus (T2DM), polycystic ovary syndrome (PCOS) and in women undergoing assisted reproductive technology (ART).

METHODS

A comprehensive review of international diabetes guidelines and a search of medical literature was performed to identify studies presenting data on the use of metformin in pregnancy. The document was approved by the councils of the two scientific societies.

RESULTS

In condition affecting the fertility, as PCOS, metformin use in pre-conception or early in pregnancy may be beneficial for clinical pregnancy, even in ART treatment, and in obese-PCOS women may reduce preterm delivery. In obese women, even in the presence of GDM or T2DM, metformin use in pregnancy is associated with a lower gestational weight gain. In pregnancy complicated by diabetes (GDM or T2DM), metformin improves maternal glycemic control and may reduce insulin dose. Neonatal and infant outcomes related to metformin exposure in utero are lacking. Metformin use in women with GDM or T2DM is associated with lower birth weight. However, an increased tendency to overweight-obesity has been observed in children, later in life.

CONCLUSIONS

Metformin may represent a therapeutic option in selected women with obesity, PCOS, GDM, T2DM, and in women undergoing ART. However, more research is required specifically on the long-term effects of in utero exposition to metformin.

Does treatment modality affect measures of arterial stiffness in women with gestational diabetes?

OBJECTIVE

To investigate whether arterial stiffness (AS) differs between healthy women and women with gestational diabetes mellitus (GDM) managed by different treatment modalities.

METHODS

This was a prospective longitudinal cohort study comparing AS in pregnancies complicated by GDM and low-risk controls. AS was assessed by recording aortic pulse-wave velocity (AoPWV), brachial augmentation index (BrAIx) and aortic augmentation index (AoAIx) using the Arteriograph® at four gestational-age windows: 24 + 0 to 27 + 6 weeks (W1); 28 + 0 to 31 + 6 weeks (W2); 32 + 0 to 35 + 6 weeks (W3) and ≥ 36 + 0 weeks (W4). Women with GDM were considered both as a single group and as subgroups stratified by treatment modality. Data were analyzed using a linear mixed model on each AS variable (log-transformed) with group, gestational-age window, maternal age, ethnicity, parity, body mass index, mean arterial pressure and heart rate as fixed effects and individual as a random effect. We compared the group means including relevant contrasts and adjusted the P-values using Bonferroni correction.

RESULTS

The study population comprised 155 low-risk controls and 127 women with GDM, of whom 59 were treated with dietary intervention, 47 were treated with metformin only and 21 were treated with metformin + insulin. The two-way interaction term of study group and gestational age was significant for BrAIx and AoAIx (P < 0.001), but there was no evidence that mean AoPWV was different between the study groups (P = 0.729). Women in the control group demonstrated significantly lower BrAIx and AoAIx compared with the combined GDM group at W1-W3, but not at W4. The mean difference in log-transformed BrAIx was -0.37 (95% CI, -0.52 to -0.22), -0.23 (95% CI, -0.35 to -0.12) and -0.29 (95% CI, -0.40 to -0.18) at W1, W2 and W3, respectively. The mean difference in log-transformed AoAIx was -0.49 (95% CI, -0.69 to -0.30), -0.32 (95% CI, -0.47 to -0.18) and -0.38 (95% CI -0.52 to -0.24) at W1, W2 and W3, respectively. Similarly, women in the control group also demonstrated significantly lower BrAIx and AoAIx compared with each of the GDM treatment subgroups (diet, metformin only and metformin + insulin) at W1-W3. The increase in mean BrAIx and AoAIx seen between W2 and W3 in women with GDM treated with dietary management was attenuated in the metformin-only and metformin + insulin groups. However, the mean differences in BrAIx and AoAIx between these treatment groups were not statistically significant at any gestational-age window.

CONCLUSIONS

Pregnancies complicated by GDM demonstrate significantly higher AS compared with low-risk pregnancies regardless of treatment modality. Our data provide the basis for further investigation into the association of metformin therapy with changes in AS and risk of placenta-mediated diseases. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Metformin Disrupts Signaling and Metabolism in Fetal Hepatocytes

Metformin is used by women during pregnancy to manage diabetes and crosses the placenta, yet its effects on the fetus are unclear. We show that the liver is a site of metformin action in fetal sheep and macaques, given relatively abundant OCT1 transporter expression and hepatic uptake following metformin infusion into fetal sheep. To determine the effects of metformin action, we performed studies in primary hepatocytes from fetal sheep, fetal macaques, and juvenile macaques. Metformin increases AMP-activated protein kinase (AMPK) signaling, decreases mammalian target of rapamycin (mTOR) signaling, and decreases glucose production in fetal and juvenile hepatocytes. Metformin also decreases oxygen consumption in fetal hepatocytes. Unique to fetal hepatocytes, metformin activates stress pathways (e.g., increased PGC1A gene expression, NRF-2 protein abundance, and phosphorylation of eIF2α and CREB proteins) alongside perturbations in hepatokine expression (e.g., increased growth/differentiation factor 15 [GDF15] and fibroblast growth factor 21 [FGF21] expression and decreased insulin-like growth factor 2 [IGF2] expression). Similarly, in liver tissue from sheep fetuses infused with metformin in vivo, AMPK phosphorylation, NRF-2 protein, and PGC1A expression are increased. These results demonstrate disruption of signaling and metabolism, induction of stress, and alterations in hepatokine expression in association with metformin exposure in fetal hepatocytes.

ARTICLE HIGHLIGHTS

The major metformin uptake transporter OCT1 is expressed in the fetal liver, and fetal hepatic uptake of metformin is observed in vivo. Metformin activates AMPK, reduces glucose production, and decreases oxygen consumption in fetal hepatocytes, demonstrating similar effects as in juvenile hepatocytes. Unique to fetal hepatocytes, metformin activates metabolic stress pathways and alters the expression of secreted growth factors and hepatokines. Disruption of signaling and metabolism with increased stress pathways and reduced anabolic pathways by metformin in the fetal liver may underlie reduced growth in fetuses exposed to metformin.

Focus on Metformin: Its Role and Safety in Pregnancy and Beyond

Metformin is used worldwide in the treatment of type 2 diabetes and has been used in the treatment of diabetes in pregnancy since the 1970s. It is highly acceptable to patients due to its ease of administration, cost and adverse effect profile. It is effective in reducing macrosomia, large-for-gestational-age infants and reduces maternal weight gain. Despite its many advantages, metformin has been associated with reductions in foetal size and has been associated with an increase in infants born small-for-gestational-age in certain cohorts. In this article, we review its efficacy, adverse effects and long-term follow-up before, during and after pregnancy for both mother and infant. We also evaluate the other forms of treatment for gestational diabetes, including oral therapies, insulin therapy and emerging treatments.

Short-term neonatal outcomes in women with gestational diabetes treated using metformin versus insulin: a systematic review and meta-analysis of randomized controlled trials

AIMS

To expand the evidence base for the clinical use of metformin, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing the efficacy and safety of metformin versus insulin with respect to short-term neonatal outcomes.

METHODS

A comprehensive search of electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) was performed. Two reviewers extracted the data and calculated pooled estimates by use of a random-effects model. In total, 24 studies involving 4355 participants met the eligibility criteria and were included in the quantitative analyses.

RESULTS

Unlike insulin, metformin lowered neonatal birth weights (mean difference - 122.76 g; 95% confidence interval [CI] - 178.31, - 67.21; p < 0.0001), the risk of macrosomia (risk ratio [RR] 0.68; 95% CI 0.54, 0.86; p = 0.001), the incidence of neonatal intensive care unit admission (RR 0.73; 95% CI 0.61, 0.88; p = 0.0009), and the incidence of neonatal hypoglycemia (RR 0.65; 95% CI 0.52, 0.81; p = 0.0001). Subgroup analysis based on the maximum daily oral dose of metformin indicated that metformin-induced neonatal birth weight loss was independent of the oral dose.

CONCLUSIONS

Our meta-analysis provides further evidence that metformin is a safe oral antihyperglycemic drug and has some benefits over insulin when used for the treatment of gestational diabetes, without an increased risk of short-term neonatal adverse outcomes. Metformin may be particularly useful in women with gestational diabetes at high risk for neonatal hypoglycemia, women who want to limit maternal and fetal weight gain, and women with an inability to afford or use insulin safely.

Diabetes and anti-diabetic interventions and the risk of gynaecological and obstetric morbidity: an umbrella review of the literature

BACKGROUND

Diabetes has reached epidemic proportions in recent years with serious health ramifications. The aim of this study was to evaluate the strength and validity of associations between diabetes and anti-diabetic interventions and the risk of any type of gynaecological or obstetric conditions.

METHODS

Design: Umbrella review of systematic reviews and meta-analyses.

DATA SOURCES

PubMed, Medline, Embase, Cochrane Database of Systematic Reviews, manual screening of references.

ELIGIBILITY CRITERIA

Systematic reviews and meta-analyses of observational and interventional studies investigating the relationship between diabetes and anti-diabetic interventions with gynaecological or obstetric outcomes. Meta-analyses that did not include complete data from individual studies, such as relative risk, 95% confidence intervals, number of cases/controls, or total population were excluded.

DATA ANALYSIS

The evidence from meta-analyses of observational studies was graded as strong, highly suggestive, suggestive or weak according to criteria comprising the random effects estimate of meta-analyses and their largest study, the number of cases, 95% prediction intervals, I² heterogeneity index between studies, excess significance bias, small study effect and sensitivity analysis using credibility ceilings. Interventional meta-analyses of randomised controlled trials were assessed separately based on the statistical significance of reported associations, the risk of bias and quality of evidence (GRADE) of included meta-analyses.

RESULTS

A total of 117 meta-analyses of observational cohort studies and 200 meta-analyses of randomised clinical trials that evaluated 317 outcomes were included. Strong or highly suggestive evidence only supported a positive association between gestational diabetes and caesarean section, large for gestational age babies, major congenital malformations and heart defects and an inverse relationship between metformin use and ovarian cancer incidence. Only a fifth of the randomised controlled trials investigating the effect of anti-diabetic interventions on women's health reached statistical significance and highlighted metformin as a more effective agent than insulin on risk reduction of adverse obstetric outcomes in both gestational and pre-gestational diabetes.

CONCLUSIONS

Gestational diabetes appears to be strongly associated with a high risk of caesarean section and large for gestational age babies. Weaker associations were demonstrated between diabetes and anti-diabetic interventions with other obstetric and gynaecological outcomes.

TRIAL REGISTRATION

Open Science Framework (OSF) (Registration https://doi.org/10.17605/OSF.IO/9G6AB ).

Screening and management of major endocrinopathies during pregnancy: an update

Endocrinopathies during pregnancy constitute a challenging issue, being prevalent and requiring appropriate management to avoid maternal and fetal complications. This review aims to summarize and present major endocrine problems during pregnancy, the appropriate screening, maternal monitoring and management, fetal monitoring, and follow-up. Glucose metabolism, thyroid function, as well as calcium and vitamin D metabolism are the main endocrine domains that should be screened and monitored during pregnancy. Gestational diabetes mellitus (GDM) is the most prevalent endocrine disease during pregnancy, followed by thyroid disorders. Specific recommendations are provided for the optimal clinical care of pregnant women and their offspring for GDM, thyroid disorders, and calcium and vitamin D disorders.

Risk factors for preterm labor: An Umbrella Review of meta-analyses of observational studies

Preterm birth defined as delivery before 37 gestational weeks, is a leading cause of neonatal and infant morbidity and mortality. Understanding its multifactorial nature may improve prediction, prevention and the clinical management. We performed an umbrella review to summarize the evidence from meta-analyses of observational studies on risks factors associated with PTB, evaluate whether there are indications of biases in this literature and identify which of the previously reported associations are supported by robust evidence. We included 1511 primary studies providing data on 170 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections and vaccines. Only seven risk factors provided robust evidence. The results from synthesis of observational studies suggests that sleep quality and mental health, risk factors with robust evidence should be routinely screened in clinical practice, should be tested in large randomized trial. Identification of risk factors with robust evidence will promote the development and training of prediction models that could improve public health, in a way that offers new perspectives in health professionals.

Antidiabetic Medication Utilisation before and during Pregnancy in Switzerland between 2012 and 2019: An Administrative Claim Database from the MAMA Cohort

Background

The incidence of diabetes mellitus (both pregestational and gestational) is increasing worldwide, and hyperglycemia during pregnancy is associated with adverse pregnancy outcomes. Evidence on the safety and efficacy of metformin during pregnancy has accumulated resulting in an increase in its prescription in many reports.

Aims

We aimed to determine the prevalence of antidiabetic drug use (insulins and blood glucose-lowering drugs) before and during pregnancy in Switzerland and the changes therein during pregnancy and over time.

Methods

We conducted a descriptive study using Swiss health insurance claims (2012-2019). We established the MAMA cohort by identifying deliveries and estimating the last menstrual period. We identified claims for any antidiabetic medication (ADM), insulins, blood glucose-lowering drugs, and individual substances within each class. We defined three groups of pattern use based on timing of dispensation: (1) dispensation of at least one ADM in the prepregnancy period and in or after trimester 2 (T2) (pregestational diabetes); (2) dispensation for the first time in or after T2 (GDM); and (3) dispensation in the prepregnancy period and no dispensation in or after T2 (discontinuers). Within the pregestational diabetes group, we further defined continuers (dispensation for the same group of ADM) and switchers (different ADM group dispensed in the prepregnancy period and in or after T2).

Results

MAMA included 104,098 deliveries with a mean maternal age at delivery of 31.7. Antidiabetic dispensations among pregnancies with pregestational and gestational diabetes increased over time. Insulin was the most dispensed medication for both diseases. Between 2017 and 2019, less than 10% of pregnancies treated for pregestational diabetes continued metformin rather than switching to insulin. Metformin was offered to less than 2% of pregnancies to treat gestational diabetes (2017-2019).

Conclusion

Despite its position in the guidelines and the attractive alternative that metformin represents to patients who may encounter barriers with insulin therapy, there was reluctance to prescribe it.

Predictors for pharmacological therapy and perinatal outcomes with metformin treatment in women with gestational diabetes

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) has been increasing in Australia and worldwide. The study aims were to examine, in comparison with dietary intervention, perinatal outcomes for women with gestational diabetes who were attending a single hospital clinic and to identify predictors for their pharmacological GDM treatment.

METHODS

A prospective, observational study of women with GDM, treated with "Diet, N= 50", "Metformin, N = 35", "Metformin and Insulin, N = 46" or "Insulin, N = 20".

FINDINGS

The mean BMI for the whole cohort was 25.8 ± 4.7 kg/m². The Metformin group, compared to the Diet group, had OR=3.1 (95% CI:1.13 to 8.25) for caesarean section birth (LSCS) compared to normal vaginal birth mode with no longer such a significant association after controlling for the number of their elective LSCS. The insulin treated group had the highest number of small for gestational age neonates (20%, p<0.05) with neonatal hypoglycaemia (25%, p< 0.05). Fasting glucose value on oral GTT (glucose tolerance test) was the strongest predictor for a pharmacological intervention requirement with OR = 2.77 (95CI%: 1.16 to 6.61), followed by timing of OGTT with OR=0.90 (95% CI: 0.83 to 0.97) and previous pregnancy loss with OR=0.28 (95% CI:0.10 to 0.74).

INTERPRETATION

These data suggest that metformin may be a safe alternative treatment to insulin treatment in GDM. Raised fasting glucose on oral GTT was the strongest indicator that GDM women with BMI < 35 kg/m² may require pharmacological therapy. Further studies are needed to identify the most effective and safe management of gestational diabetes within the public hospital setting.

AUSTRALIAN NEW ZEALAND CLINICAL TRIAL REGISTRY ANZCTR TRIAL ID

ACTRN12620000397910.

Sex-specific effects of maternal metformin intervention during glucose-intolerant obese pregnancy on body composition and metabolic health in aged mouse offspring

AIMS/HYPOTHESIS

Metformin is increasingly used to treat gestational diabetes (GDM) and pregnancies complicated by pregestational type 2 diabetes or polycystic ovary syndrome but data regarding long-term offspring outcome are lacking in both human studies and animal models. Using a mouse model, this study investigated the effects of maternal metformin intervention during obese glucose-intolerant pregnancy on adiposity, hepatic steatosis and markers of metabolic health of male and female offspring up to the age of 12 months.

METHODS

C57BL/6J female mice were weaned onto either a control diet (Con) or, to induce pre-conception obesity, an obesogenic diet (Ob). The respective diets were maintained throughout pregnancy and lactation. These obese dams were then randomised to the untreated group or to receive 300 mg/kg oral metformin hydrochloride treatment (Ob-Met) daily during pregnancy. In male and female offspring, body weights and body composition were measured from 1 month until 12 months of age, when serum and tissues were collected for investigation of adipocyte cellularity (histology), adipose tissue inflammation (histology and quantitative RT-PCR), and hepatic steatosis and fibrosis (histochemistry and modified Folch assay).

RESULTS

At 12 months of age, male Ob and Ob-Met offspring showed increased adiposity, adipocyte hypertrophy, elevated expression of proinflammatory genes, hyperleptinaemia and hepatic lipid accumulation compared with Con offspring. Male Ob-Met offspring failed to show hyperplasia between 8 weeks and 12 months, indicative of restricted adipose tissue expansion, resulting in increased immune cell infiltration and ectopic lipid deposition. Female Ob offspring were relatively protected from these phenotypes but Ob-Met female offspring showed increased adiposity, adipose tissue inflammation, hepatic lipid accumulation, hyperleptinaemia and hyperinsulinaemia compared with Con female offspring.

CONCLUSIONS/INTERPRETATION

Maternal metformin treatment of obese dams increased offspring metabolic risk factors in a sex- and age-dependent manner. These observations highlight the importance of following up offspring of both sexes beyond early adulthood after interventions during pregnancy. Our findings illustrate the complexity of balancing short-term benefits to mother and child vs any potential long-term metabolic effects on the offspring when prescribing therapeutic agents that cross the placenta.

Metformin in pregnancy and risk of abnormal growth outcomes at birth: a register-based cohort study

We previously reported an increased risk of being small for gestational age (SGA) and a decreased risk of being large for gestational age (LGA) after in utero exposure to metformin compared with insulin exposure. This follow-up study investigated if these observations remain when metformin exposure (henceforth, metformin cohort) is compared with non-pharmacological antidiabetic treatment of gestational diabetes mellitus (GDM; naïve cohort), instead of insulin. RESEARCH DESIGN AND METHODS : This was a Finnish population register-based cohort study from singleton children born during 2004-2016. Birth outcomes from metformin cohort (n=3964) and the naïve cohort (n=82 675) were used in the main analyses. Additional analyses were conducted in a subcohort, restricting the metformin cohort to children of mothers with GDM only (n=2361). Results were reported as inverse probability of treatment weighted OR (wOR), with the naïve cohort as reference. RESULTS  : No difference was found for the outcome of SGA between the cohorts in the main analyses (wOR 0.97, 95% CI 0.73 to 1.27) or in the additional analyses (wOR 1.01, 95% CI 0.75 to 1.37). No difference between the cohorts was found for the risk of LGA (wOR 0.91, 95% CI 0.75 to 1.11) in the main analyses but a decreased risk was observed in the additional analyses (wOR 0.72, 95% CI 0.56 to 0.92). CONCLUSIONS : This follow-up study found no increase in the risk of SGA or LGA after in utero exposure to metformin, compared with drug-naïve GDM. The decreased risk of LGA in mothers with GDM may suggest residual confounding. The lack of increased SGA risk aligns with findings from studies using metformin in non-diabetic pregnancies. In contrast, lower birth weight and increased SGA birth risk were observed in GDM pregnancies for metformin versus insulin. Metformin should be avoided with emerging growth restriction in utero. The interplay of intrauterine hyperglycemia and pharmacological treatments needs further assessment.

A Review on the Use of Metformin in Pregnancy and Its Associated Fetal Outcomes

A commonly used first-line anti-diabetic medication, metformin, has been used in pregnancy. The drug is known to have specific effects on different organs around the body. One of these organs includes the ovaries. Therefore, for more than 40 years, it has often been prescribed for maternal obesity along with gestational diabetes mellitus. Untreated pregnancies like these frequently result in complications for both the mother and the fetus, like macrosomia, pregnancy-induced hypertension, obstructed labor, stillbirths, and perinatal deaths. In addition, there is also evidence that these mothers tend to develop type II diabetes mellitus during their pregnancy and even a few years post-delivery. These complications can be controlled or even reduced with the help of metformin, sometimes combining it with insulin or clomiphene citrate if required. There is still a need to cautiously prescribe the drug by outweighing its benefits against the risk associated with it. The current research on the subject leans more towards the benefits offered to the mother during pregnancy. Only a few randomized, controlled trials have been conducted on the fetal condition after the mother has been administered metformin.

Furthermore, these studies lack the appropriate sample size and long-term follow-up on these metformin-exposed offspring. As a result, there are no reliable data available to clinicians and physicians about the drug. Owing to its benefits in certain pregnancies, it is less likely that the drug will cease to be prescribed. Therefore, it becomes increasingly imperative to conduct more research on this topic to ensure the drug is safe for the mother and the offspring.

COVID-19 and Gestational Diabetes: The Role of Nutrition and Pharmacological Intervention in Preventing Adverse Outcomes

Pregnant women with GDM affected by COVID-19 seem to be at higher risk of adverse maternal and neonatal outcomes, especially those with overweight or obesity. Good glycemic control seems to be the most effective measure in reducing the risk of GDM and severe COVID-19. For such purposes, the Mediterranean diet, micronutrient supplementation, and physical activity are considered the first line of treatment. Failure to achieve glycemic control leads to the use of insulin, and this clinical scenario has been shown to be associated with an increased risk of adverse maternal and neonatal outcomes. In this review, we explore the current evidence pertaining to the pathogenesis of SARS-CoV-2 leading to the main complications caused by COVID-19 in patients with GDM. We also discuss the incidence of complications caused by COVID-19 in pregnant women with GDM according to their treatment.

Metformin Prevents Key Mechanisms of Obesity-Related Complications in Visceral White Adipose Tissue of Obese Pregnant Mice

With the gaining prevalence of obesity, related risks during pregnancy are rising. Inflammation and oxidative stress are considered key mechanisms arising in white adipose tissue (WAT) sparking obesity-associated complications and diseases. The established anti-diabetic drug metformin reduces both on a systemic level, but only little is known about such effects on WAT. Because inhibiting these mechanisms in WAT might prevent obesity-related adverse effects, we investigated metformin treatment during pregnancy using a mouse model of diet-induced maternal obesity. After mating, obese mice were randomised to metformin administration. On gestational day G15.5, phenotypic data were collected and perigonadal WAT (pgWAT) morphology and proteome were examined. Metformin treatment reduced weight gain and visceral fat accumulation. We detected downregulation of perilipin-1 as a correlate and observed indications of recovering respiratory capacity and adipocyte metabolism under metformin treatment. By regulating four newly discovered potential adipokines (alpha-1 antitrypsin, Apoa4, Lrg1 and Selenbp1), metformin could mediate anti-diabetic, anti-inflammatory and oxidative stress-modulating effects on local and systemic levels. Our study provides an insight into obesity-specific proteome alterations and shows novel modulating effects of metformin in pgWAT of obese dams. Accordingly, metformin therapy appears suitable to prevent some of obesity’s key mechanisms in WAT.

Antenatal insulin therapy in gestational diabetes mellitus: validation of the new Brugmann scores

BACKGROUND

Following the adoption of the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria for gestational diabetes mellitus (GDM) diagnosis by the World Health Organization (WHO) in 2014, many investigators have tried to identify independent risk factors for antenatal insulin therapy (AIT). The purpose of the current study is to build and validate a score that stratifies patients according to their need for AIT.

METHODS

All pregnant women diagnosed with GDM according to the IADPSG definition were included. Group 1 comprised patients of 2018, and group 2 comprised patients of 2019. Each group was divided into two subgroups: subgroup A comprised patients diagnosed according to the 75-g oral glucose tolerance test (OGTT), and subgroup B comprised patients diagnosed according to fasting plasma glucose (FPG).

RESULTS

A total of 1298 patients were included; 19.3% of those diagnosed by OGTT and 40.9% by FPG required AIT. The risk for AIT was stratified as low, moderate, and high. Brugmann FPG score comprised six risk factors and Brugmann OGTT score 12. Higher scores were associated with higher risk for AIT. The use of these scores in the two subgroups of group 2 showed no statistical differences compared to group 1.

CONCLUSIONS

Both Brugmann FPG and OGTT scores may be useful to stratify patients with GDM according to their need for AIT. Future studies should be conducted to prospectively validate these scores, and to examine whether or not using oral anti-hyperglycemic agents in a high-risk group may decrease the need for AIT.

Pregnancy Outcomes: Effects of Metformin (POEM) study: a protocol for a long-term, multicentre, open-label, randomised controlled trial in gestational diabetes mellitus

INTRODUCTION

Gestational diabetes mellitus (GDM) is a common disorder of pregnancy with health risks for mother and child during pregnancy, delivery and further lifetime, possibly leading to type 2 diabetes mellitus (T2DM). Current treatment is focused on reducing hyperglycaemia, by dietary and lifestyle intervention and, if glycaemic targets are not reached, insulin. Metformin is an oral blood glucose lowering drug and considered safe during pregnancy. It improves insulin sensitivity and has shown advantages, specifically regarding pregnancy-related outcomes and patient satisfaction, compared with insulin therapy. However, the role of metformin in addition to usual care is inconclusive and long-term outcome of metformin exposure in utero are lacking. The primary aim of this study is to investigate the early addition of metformin on pregnancy and long-term outcomes in GDM.

METHODS AND ANALYSIS

The Pregnancy Outcomes: Effects of Metformin study is a multicentre, open-label, randomised, controlled trial. Participants include women with GDM, between 16 and 32 weeks of gestation, who are randomised to either usual care or metformin added to usual care, with insulin rescue in both groups. Metformin is given up to 1 year after delivery. The study consists of three phases (A-C): A-until 6 weeks after delivery; B-until 1 year after delivery; C-observational study until 20 years after delivery. During phase A, the primary outcome is a composite score consisting of: (1) pregnancy-related hypertension, (2) large for gestational age neonate, (3) preterm delivery, (4) instrumental delivery, (5) caesarean delivery, (6) birth trauma, (7) neonatal hypoglycaemia, (8) neonatal intensive care admission. During phase B and C the primary outcome is the incidence of T2DM and (weight) development in mother and child.

ETHICS AND DISSEMINATION

The study was approved by the Central Committee on Research Involving Human Subjects in the Netherlands. Results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02947503.

Changing patterns in medication prescription for gestational diabetes during a time of guideline change in the USA: a cross-sectional study

OBJECTIVE

To define patterns of prescription and factors associated with choice of pharmacotherapy for gestational diabetes mellitus (GDM), namely metformin, glyburide and insulin, during a period of evolving professional guidelines.

DESING

Cross-sectional study.

SETTING

US commercial insurance beneficiaries from Market-Scan (late 2015 to 2018).

STUDY DESIGN

We included women with GDM, singleton gestations, 15-51 years of age on pharmacotherapy. The exposure was pharmacy claims for metformin, glyburide and insulin.

MAIN OUTCOMES

Pharmacotherapy for GDM with either oral agent, metformin or glyburide, compared with insulin as the reference, and secondarily, consequent treatment modification (addition and/or change) to metformin, glyburide or insulin.

RESULTS

Among 37 762 women with GDM, we analysed data from 10 407 (28%) with pharmacotherapy, 21% with metformin (n = 2147), 48% with glyburide (n = 4984) and 31% with insulin (n = 3276). From late 2015 to 2018, metformin use increased from 17 to 29%, as did insulin use from 26 to 44%, whereas glyburide use decreased from 58 to 27%. By 2018, insulin was the most common pharmacotherapy for GDM; metformin was more likely to be prescribed by 9% compared with late 2015/16, but glyburide was less likely by 45%. Treatment modification occurred in 20% of women prescribed metformin compared with 2% with insulin and 8% with glyburide.

CONCLUSIONS

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for GDM among a privately insured US population during a time of evolving professional guidelines. Further evaluation of the relative effectiveness and safety of metformin compared with insulin is needed.

TWEETABLE ABSTRACT

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for gestational diabetes mellitus in the USA.

Impact Of Prepregnancy Overweight And Obesity On Treatment Modality And Pregnancy Outcome In Women With Gestational Diabetes Mellitus

BACKGROUND

We aim to evaluate the impact of prepregnancy overweight on treatment modalities of Gestational Diabetes Mellitus (GDM). We assessed the association of increased pregravid Body Mass Index (BMI) with dosing of basal and rapid acting insulin as well as pregnancy outcome.

METHODS

We included 509 gestational diabetic women (normal weight: 200, overweight: 157, obese: 152), attending the pregnancy outpatient clinic at the Department of Obstetrics and Gynecology, Medical University of Vienna, in this retrospective study. We used a prospectively compiled database to assess patient characteristics, treatment approaches - particularly maximum doses of basal and rapid acting insulin or metformin - and pregnancy outcome.

RESULTS

Increased BMI was associated with the need of glucose lowering medication (odds ratio (OR): 1.08 for the increase of 1 kg/m² BMI, 95%CI 1.05-1.11, p<0.001). Mothers with pregestational obesity received the highest amount of insulin. Metformin was more often used in patients with obesity who also required higher daily doses. Maternal BMI was associated with increased risk of cesarean section (OR 1.04, 95%CI 1.01-1.07, p<0.001) and delivering large for gestational age offspring (OR 1.09, 95%CI 1.04-1.13, p<0.001). Birthweight percentiles were highest in patients with obesity who required glucose lowering therapy.

CONCLUSIONS

Treatment modalities and outcome in GDM pregnancies are closely related to the extent of maternal BMI. Patients with obesity required glucose lowering medication more often and were at higher risk of adverse pregnancy outcomes. It is crucial to further explore the underlying pathophysiologic mechanisms to optimize clinical management and individual treatment approaches.

Metformin in pregnancy and risk of adverse long-term outcomes: a register-based cohort study

This study aimed to investigate if maternal pregnancy exposure to metformin is associated with increased risk of long-term and short-term adverse outcomes in the child. RESEARCH DESIGN AND METHODS : This register-based cohort study from Finland included singleton children born 2004-2016 with maternal pregnancy exposure to metformin or insulin (excluding maternal type 1 diabetes): metformin only (n=3967), insulin only (n=5273) and combination treatment (metformin and insulin; n=889). The primary outcomes were long-term offspring obesity, hypoglycemia, hyperglycemia, diabetes, hypertension, polycystic ovary syndrome, and challenges in motor-social development. In a sensitivity analysis, the primary outcomes were investigated only among children with maternal gestational diabetes. Secondary outcomes were adverse outcomes at birth. Analyses were conducted using inverse- probability of treatment weighting (IPTW), with insulin as reference. RESULTS  : Exposure to metformin or combination treatment versus insulin was not associated with increased risk of long-term outcomes in the main or sensitivity analyses. Among the secondary outcomes, increased risk of small for gestational age (SGA) was observed for metformin (IPTW-weighted OR 1.65, 95% CI 1.16 to 2.34); increased risk of large for gestational age, preterm birth and hypoglycemia was observed for combination treatment. No increased risk was observed for neonatal mortality, hyperglycemia, or major congenital anomalies. CONCLUSIONS : This study found no increased long-term risk associated with pregnancy exposure to metformin (alone or in combination with insulin), compared with insulin. The increased risk of SGA associated with metformin versus insulin suggests caution in pregnancies with at-risk fetal undernutrition. The increased risks of adverse outcomes at birth associated with combination treatment may reflect confounding by indication or severity.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

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.

Long-term effects of metformin use in gestational diabetes mellitus on offspring health

Metformin is the first-line drug for the treatment of type 2 diabetes mellitus, but its role in gestational diabetes mellitus (GDM) management is not clear. Recent evidence suggests a certain beneficial effect of metformin in the treatment of GDM, but a high treatment failure rate leads to the initiation of additional medications, such as insulin. Moreover, since metformin crosses the placental barrier and reaches a significant level in the fetus, it is likely to influence the fetal metabolic milieu. The evidence indicates the long-term safety in children exposed to metformin in utero except for mild adverse anthropometric profiles. Diligent follow-up of metformin-exposed offspring is warranted from the clinician’s point of view.

Metformin for gestational diabetes study: metformin vs insulin in gestational diabetes: glycemic control and obstetrical and perinatal outcomes: randomized prospective trial

BACKGROUND

Gestational diabetes that is not properly controlled with diet has been commonly treated with insulin. In recent years, several studies have published that metformin can lead to, at least, similar obstetrical and perinatal outcomes as insulin. Nevertheless, not all clinical guidelines endorse its use, and clinical practice is heterogeneous.

OBJECTIVE

This study aimed to test whether metformin could achieve the same glycemic control as insulin and similar obstetrical and perinatal results, with a good safety profile, in women with gestational diabetes that is not properly controlled with lifestyle changes.

STUDY DESIGN

The metformin for gestational diabetes study was a multicenter, open-label, parallel arms, randomized clinical trial performed at 2 hospitals in Málaga (Spain), enrolling women with gestational diabetes who needed pharmacologic treatment. Women at the age of 18 to 45 years, in the second or third trimesters of pregnancy, were randomized to receive metformin or insulin (detemir or aspart). The main outcomes were (1) glycemic control (mean glycemia, preprandial and postprandial) and hypoglycemic episodes and (2) obstetrical and perinatal outcomes and complications (hypertensive disorders, type of labor, prematurity, macrosomia, large for gestational age, neonatal care unit admissions, respiratory distress syndrome, hypoglycemia, jaundice). Outcomes were analyzed on an intention-to-treat basis.

RESULTS

Between October 2016 and June 2019, 200 women were randomized, 100 to the insulin-treated group and 100 to the metformin-treated group. Mean fasting and postprandial glycemia did not differ between groups, but postprandial glycemia was significantly better after lunch or dinner in the metformin-treated-group. Hypoglycemic episodes were significantly more common in the insulin-treated group (55.9% vs 17.7% on metformin; odds ratio, 6.118; 95% confidence interval, 3.134-11.944; P=.000). Women treated with metformin gained less weight from the enrollment to the prepartum visit (36-37 gestational weeks) (1.35±3.21 vs 3.87±3.50 kg; P=.000). Labor inductions (45.7% [metformin] vs 62.5% [insulin]; odds ratio, 0.506; 95% confidence interval, 0.283-0.903; P=.029) and cesarean deliveries (27.6% [metformin] vs 52.6% [insulin]; odds ratio, 0.345; 95% confidence interval, 0.187-0.625; P=.001) were significantly lower in the metformin-treated group. Mean birthweight, macrosomia, and large for gestational age and babies' complications were not different between treatment groups. The lower cesarean delivery rate for women treated with metformin was not associated with macrosomia, large or small for gestational age, or other complications of pregnancy.

CONCLUSION

Metformin treatment was associated with a better postprandial glycemic control than insulin for some meals, a lower risk of hypoglycemic episodes, less maternal weight gain, and a low rate of failure as an isolated treatment. Most obstetrical and perinatal outcomes were similar between groups.

Effects of Different Glucose-Lowering Measures on Maternal and Infant Outcomes in Pregnant Women with Gestational Diabetes: A Network Meta-analysis

INTRODUCTION

A network meta-analysis was conducted to compare and rank the effects of different glucose-lowering measures on maternal and infant outcomes in pregnant women with gestational diabetes mellitus (GDM).

METHODS

We searched the PubMed, CNKI, Embase, Cochrane Library, Wanfang, and Weipu databases for relevant studies published between database establishment and June 2021. Study retrieval involved subject-heading and keyword searches. Randomized controlled trials (RCTs) with different glucose-lowering treatments for GDM patients were included. The Cochrane tool was used to assess bias risk. Pairwise and network meta-analyses were used to compare and rank the effects of different hypoglycemic measures on maternal and infant outcomes in pregnant women with GDM.

RESULTS

We included 41 RCTs involving 6245 pregnant women with GDM. Patients treated with insulin had a higher incidence of neonatal intensive care unit (NICU) occupancy (1.3, 95% CI 1.0-1.7) than those treated with metformin. The insulin (1.5, 95% CI 1.1-2.1 and 1.8, 95% CI 1.0-3.3) and glyburide (2.0, 95% CI 1.2-3.2 and 2.5, 95% CI 1.1-8.4) groups exhibited higher incidences of neonatal hypoglycemia and large for gestational age (LGA) newborns than the metformin group. The glyburide group exhibited a lower probability of cesarean section than the metformin (0.76, 95% CI 0.55-1.0) and insulin (0.71, 95% CI 0.52-0.96) groups. Preeclampsia incidence in the diet and exercise groups was significantly lower than in the metformin (0.19, 95% CI 0.043-0.72) and insulin (0.15, 95% CI 0.032-0.52) groups. No intervention significantly reduced the incidences of macrosomia, preterm birth, gestational hypertension, or respiratory distress syndrome (RDS). The ranking results showed that the metformin group had the lowest rates of neonatal hypoglycemia, macrosomia, LGA, and NICU occupancy. The glyburide group had the lowest NICU occupancy and cesarean section rates and the highest neonatal hypoglycemia, LGA, preeclampsia, and gestational hypertension rates. The diet and exercise group had the lowest preterm delivery and preeclampsia rates and the highest NICU occupancy rate.

CONCLUSION

Metformin is a potentially superior choice for GDM treatment because it is associated with minimal incidences of multiple adverse pregnancy outcome indicators and does not lead to high values of certain adverse outcome indices. Other hypoglycemic agent or diet groups exhibit high incidences of certain adverse outcomes. Therefore, when selecting a GDM treatment strategy, the efficacies and risks of different treatment programs should be evaluated according to the scenario in hand.

Gestational metformin administration in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized control studies

AIMS

To evaluate metformin's effects on pregnancy outcomes in women with polycystic ovary syndrome.

METHODS

A literature search was conducted using PubMed, EMBASE, Web of Science, MEDLINE, and the Cochrane Library. All randomized controlled trials comparing metformin administration during pregnancy versus placebo or blank in PCOS women were selected. The primary outcomes were the incidence of gestational diabetes mellitus (GDM), preterm delivery, and miscarriage. We combined data with the Review Manager. Bayesian meta-analysis was employed for further verification with the R software.

RESULTS

Six randomized control trial studies involving 1229 participants were included. Metformin use was associated with reduced risk of preterm delivery (Risk ratios [RR], 0.45; 95% CI, 0.25-0.80; p, 0.007) and higher larger neonatal head circumference (Mean difference (MD), 0.47; 95% CI, 0.20-0.74; p, 0.0006] but had no effect on the incidence of GDM (RR 1.87; 95% CI, 0.58-1.87; p, 0.89), miscarriage (RR, 0.85; 95% CI, 0.45-1.60; p, 0.62), pre-eclampsia (RR, 1.18; 95% CI, 0.43-3.21; p, 0.75), neonatal length (MD, 0.33; 95% CI, -0.12-0.78; p, 0.15) and birthweight (MD, 73.78; 95% CI, -52.98-200.53; p, 0.17).

CONCLUSIONS

Metformin administration in PCOS pregnancies was associated with reduced preterm delivery risk and larger neonatal head circumference.

Metformin in Pregnancy for Women with Type 2 Diabetes: a Review

PURPOSE OF REVIEW

To review the current evidence for the use of metformin in pregnancy for women with type 2 diabetes.

RECENT FINDINGS

A large, multicenter, double-blind randomized controlled trial found that women with type 2 diabetes in pregnancy treated with metformin as an adjunct to insulin therapy had less gestational weight gain, insulin requirements, caesarian sections, macrosomia, and neonatal adiposity, but more neonates were small for gestational age (SGA) compared with insulin alone. It is unclear if the higher number of SGA infants are a direct result of metformin exposure or mediated through other effects such as less gestational weight gain and improved glycemic control. Additional follow-up studies of offspring exposed to metformin in utero are required. Metformin may be a useful adjunctive treatment for women with type 2 diabetes in pregnancy to help meet glycemic targets if there are no concerns for or indications of SGA.

The efficacy and safety of metformin alone or as an add-on therapy to insulin in pregnancy with GDM or T2DM: A systematic review and meta-analysis of 21 randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Pregnant women are increasingly being exposed to metformin for conditions including gestational diabetes mellitus and type 2 diabetes mellitus. Metformin has been found to exhibit maternal to foetal transfer, and the long-term influence is uncertain. We conducted a meta-analysis to compare the efficacy and safety of metformin alone or as add-on therapy to insulin and insulin in pregnancy with gestational diabetes mellitus or type 2 diabetes mellitus.

METHODS

We performed a comprehensive literature search of PubMed, Embase, Cochrane Library and ClinicalTrials.gov for randomized controlled trials (RCTs) that compared metformin to insulin in pregnancy. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were used to synthesize the results. Two authors independently extracted the data, evaluated study quality and calculated pooled estimates.

RESULTS

Twenty-one studies involving 4,545 patients were included in this meta-analysis. Compared with insulin, metformin significantly reduced the risks of maternal weight gain [MD -1.51 kg, 95%CI (-1.90 kg, -1.12 kg), P < 0.00001], gestational age at birth [MD -0.12 week, 95%CI (-0.21 week, -0.02 week), P = 0.02], gestational hypertension [RR 0.63, 95%CI (0.48, 0.82), P = 0.0006], maternal hypoglycaemia [RR 0.33, 95%CI (0.15, 0.73), P = 0.006], birthweight [MD -0.13 kg, 95%CI (-0.20 kg, -0.07 kg), P < 0.0001], neonatal hypoglycaemia [RR 0.56, 95%CI (0.49, 0.64), P < 0.00001], neonatal intensive care unit admission [RR 0.73, 95%CI (0.64, 0.83), P < 0.00001], birthweight ≥4000 g [RR 0.70, 95%CI (0.59, 0.83), P < 0.0001], and large for gestational age [RR 0.83, 95%CI (0.72, 0.97), P = 0.02] and significantly increased the risk of small for gestational age [RR 1.43, 95%CI (1.08, 1.89), P = 0.01] in pregnancy.

WHAT IS NEW AND CONCLUSION

Metformin may have potential benefits for pregnant women and newborns in terms of maternal and foetal outcomes. More studies with long-term follow-up of offspring exposed to metformin in utero are needed to provide evidence for the future use of metformin in pregnancy.

Metformin Perturbs Pancreatic Differentiation From Human Embryonic Stem Cells

Metformin is becoming a popular treatment before and during pregnancy, but current literature on in utero exposure to metformin lacks long-term clinical trials and mechanistic studies. Current literature on the effects of metformin on mature pancreatic β-cells highlights its dual, opposing, protective, or inhibitory effects, depending on metabolic environment. However, the impact of metformin on developing human pancreatic β-cells remains unknown. In this study, we investigated the potential effects of metformin exposure on human pancreatic β-cell development and function in vitro. In the absence of metabolic challenges such as high levels of glucose and fatty acids, metformin exposure impaired the development and function of pancreatic β-cells, with downregulation of pancreatic genes and dysfunctional mitochondrial respiration. It also affected the insulin secretion function of pancreatic β-cells. These findings call for further in-depth evaluation of the exposure of human embryonic and fetal tissue during pregnancy to metformin and its implications for long-term offspring health.

Maternal Metformin Intervention during Obese Glucose-Intolerant Pregnancy Affects Adiposity in Young Adult Mouse Offspring in a Sex-Specific Manner

Background: Metformin is commonly used to treat gestational diabetes mellitus. This study investigated the effect of maternal metformin intervention during obese glucose-intolerant pregnancy on the gonadal white adipose tissue (WAT) of 8-week-old male and female mouse offspring. Methods: C57BL/6J female mice were provided with a control (Con) or obesogenic diet (Ob) to induce pre-conception obesity. Half the obese dams were treated orally with 300 mg/kg/d of metformin (Ob-Met) during pregnancy. Gonadal WAT depots from 8-week-old offspring were investigated for adipocyte size, macrophage infiltration and mRNA expression of pro-inflammatory genes using RT-PCR. Results: Gestational metformin attenuated the adiposity in obese dams and increased the gestation length without correcting the offspring in utero growth restriction and catch-up growth caused by maternal obesity. Despite similar body weight, the Ob and Ob-Met offspring of both sexes showed adipocyte hypertrophy in young adulthood. Male Ob-Met offspring had increased WAT depot weight (p < 0.05), exaggerated adipocyte hyperplasia (p < 0.05 vs. Con and Ob offspring), increased macrophage infiltration measured via histology (p < 0.05) and the mRNA expression of F4/80 (p < 0.05). These changes were not observed in female Ob-Met offspring. Conclusions: Maternal metformin intervention during obese pregnancy causes excessive adiposity, adipocyte hyperplasia and WAT inflammation in male offspring, highlighting sex-specific effects of prenatal metformin exposure on offspring WAT.

Prevention of Hypertensive Disorders of Pregnancy-Is There a Place for Metformin?

The possibility of prophylaxis of hypertensive disorders of pregnancy (HDPs) such as preeclampsia (PE) and pregnancy-induced hypertension is of interest due to the unpredictable course of these diseases and the risks they carry for both mother and fetus. It has been proven that their development is associated with the presence of the placenta, and the processes that initiate it begin at the time of the abnormal invasion of the trophoblast in early pregnancy. The ideal HDP prophylaxis should alleviate the influence of risk factors and, at the same time, promote physiological trophoblast invasion and maintain the physiologic endothelium function without any harm to both mother and fetus. So far, aspirin is the only effective and recommended pharmacological agent for the prevention of HDPs in high-risk groups. Metformin is a hypoglycemic drug with a proven protective effect on the cardiovascular system. Respecting the anti-inflammatory properties of metformin and its favorable impact on the endothelium, it seems to be an interesting option for HDP prophylaxis. The results of previous studies on such use of metformin are ambiguous, although they indicate that in a certain group of pregnant women, it might be effective in preventing hypertensive complications. The aim of this study is to present the possibility of metformin in the prevention of hypertensive disorders of pregnancy with respect to its impact on the pathogenic elements of development

Prescribing for pregnancy: managing diabetes

Topics for DTB review articles are selected by DTB's editorial board to provide concise overviews of medicines and other treatments to help patients get the best care. Articles include a summary of key points and a brief overview for patients. Articles may also have a series of multiple choice CME questions.

Metformin Use in Gestational Diabetes: Awareness, Attitude, and Practice among Healthcare Professionals in Malaysia

Background:

Metformin has been added in the Malaysian clinical practice guideline (CPG) as one of the first-line options in the management of gestational diabetes mellitus (GDM); however, the uptake on this practice among healthcare professionals is unknown.

Objective:

The objective of the study is to determine the awareness, attitude, and practice and their predictors on the use of metformin for GDM among healthcare professionals in Malaysia.

Materials and Methods:

This was a multicenter, cross-sectional study in three tertiary hospitals in Malaysia. Medical doctors and pharmacists working in several departments were invited to participate in a survey using self-administered questionnaires.

Results:

From 350 questionnaires distributed, 225 were completed by medical doctors (43.1%), pharmacists (40.4%), and specialists (7.5%). Less than 30% of them were aware on the option of using metformin as one of the first-line agents in GDM. Education level, department, and profession were found to be associated with the awareness level (P = 0.016, P = 0.004, and P = 0.001, respectively). 70.2% of the respondents showed a positive attitude toward metformin use in GDM. Only 64 (28.4%) of the respondents have prescribed/dispensed metformin for GDM before, although more than half will consider doing so in the future. Having postgraduate qualifications increased the likelihood of having a good awareness (odds ratio [OR]: 2.44, 95% confidence interval [CI] 1.23–4.85) and to consider prescribing/dispensing metformin for GDM patients (OR: 2.27, 95% CI 1.08–4.78).

Conclusion:

Despite a positive attitude toward metformin use in GDM among healthcare professionals in Malaysia, their awareness level on this practice was low as they currently prefer the use of insulin over metformin.

Impact of metformin treatment during pregnancy on maternal outcomes: a systematic review/meta-analysis

We systematically assessed the impact of metformin treatment on maternal pregnancy outcomes. PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov and Cochrane databases were systematically searched (inception-1st February 2021). Randomised controlled trials reporting pregnancy outcomes in women randomised to metformin versus any other treatment for any indication were included. Outcomes included gestational weight gain (GWG), pre-eclampsia, gestational hypertension, preterm birth, gestational age at delivery, caesarean section, gestational diabetes, glycaemic control, and gastrointestinal side-effects. Two independent reviewers conducted screening, with a third available to evaluate disagreements. Risk-of-bias and GRADE assessments were conducted using Cochrane Risk-of-Bias and GRADE-pro software. Thirty-five studies (n = 8033 pregnancies) met eligibility criteria. GWG was lower in pregnancies randomised to metformin versus other treatments (1.57 kg ± 0.60 kg; I₂ = 86%, p < 0.0001), as was likelihood of pre-eclampsia (OR 0.69, 95% CI 0.50-0.95; I₂ = 55%, p = 0.02). The risk of gastrointestinal side-effects was greater in metformin-exposed versus other treatment groups (OR 2.43, 95% CI 1.53-3.84; I₂ = 76%, p = 0.0002). The risk of other maternal outcomes assessed was not significantly different between metformin-exposed versus other treatment groups. Metformin for any indication during pregnancy is associated with lower GWG and a modest reduced risk of pre-eclampsia, but increased gastrointestinal side-effects compared to other treatments.

Effect of metformin on biomarkers of placental- mediated disease: A systematic review and meta-analysis

Metformin reduces the incidence of placental-mediated disease (PMD) in pregnancies with and without diabetes, but the mechanism through which it exerts these effects is not yet fully understood. We performed a systematic review and meta-analysis to examine the effect of metformin on biomarkers implicated in the pathogenesis of PMD. We searched Medline, Embase and the Cochrane Library for studies of metformin and biomarkers of PMD in pregnancy. Meta-analysis was undertaken where comparable data were obtained from two or more studies. 12 studies were included in the final review. Meta-analysis of 2 studies including 323 pregnant women showed significantly reduced CRP levels following treatment with metformin compared to placebo [mean difference = -1.72, 95% CI (-2.97; -0.48); p = 0.007]. Metformin exposure was also associated with decreased levels of the inflammatory cytokines TNFα, IL-1a, IL-1b and IL-6 in serum, placenta and omental tissue taken from pregnant women. Metformin significantly decreased the release of anti-angiogenic factors sFlt-1 and sEng from ex-vivo placental and umbilical vein tissue, and increased maternal serum levels of non-phosphorylated IGFBP-1. Overall, our findings show that metformin mediates several molecular pathways implicated in the pathogenesis of pre-eclampsia and intrauterine growth retardation. Metformin therefore has exciting potential as a therapeutic, as well as preventative, agent in the treatment of PMD, which warrants further investigation.

The anabolic role of the Warburg, Cori-cycle and Crabtree effects in health and disease

In evolution, genes survived that could code for metabolic pathways, promoting long term survival during famines or fasting when suffering from trauma, disease or during physiological growth. This requires utilization of substrates, already present in some form in the body. Carbohydrate stores are limited and to survive long, their utilization is restricted to survival pathways, by inhibiting glucose oxidation and glycogen synthesis. This leads to insulin resistance and spares muscle protein, because being the main supplier of carbon for new glucose production. In these survival pathways, part of the glucose is degraded in glycolysis in peripheral (muscle) tissues to pyruvate and lactate (Warburg effect), which are partly reutilized for glucose formation in liver and kidney, completing the Cori-cycle. Another part of the glucose taken up by muscle contributes, together with muscle derived amino acids, to the production of substrates consisting of a complete amino acid mix but extra non-essential amino acids like glutamine, alanine, glycine and proline. These support cell proliferation, matrix deposition and redox regulation in tissues, specifically active in host response and during growth. In these tissues, also glucose is taken up delivering glycolytic intermediates, that branch off and act as building blocks and produce reducing equivalents. Lactate is also produced and released in the circulation, adding to the lactate released by muscle in the Cori-cycle and completing secondary glucose cycles. Increased fluxes through these cycles lead to modest hyperglycemia and hyperlactatemia in states of healthy growth and disease and are often misinterpreted as induced by hypoxia.

Improvement Effect of Metformin on Female and Male Reproduction in Endocrine Pathologies and Its Mechanisms

Metformin (MF), a first-line drug to treat type 2 diabetes mellitus (T2DM), alone and in combination with other drugs, restores the ovarian function in women with polycystic ovary syndrome (PCOS) and improves fetal development, pregnancy outcomes and offspring health in gestational diabetes mellitus (GDM) and T2DM. MF treatment is demonstrated to improve the efficiency of in vitro fertilization and is considered a supplementary drug in assisted reproductive technologies. MF administration shows positive effect on steroidogenesis and spermatogenesis in men with metabolic disorders, thus MF treatment indicates prospective use for improvement of male reproductive functions and fertility. MF lacks teratogenic effects and has positive health effect in newborns. The review is focused on use of MF therapy for restoration of female and male reproductive functions and improvement of pregnancy outcomes in metabolic and endocrine disorders. The mechanisms of MF action are discussed, including normalization of metabolic and hormonal status in PCOS, GDM, T2DM and metabolic syndrome and restoration of functional activity and hormonal regulation of the gonadal axis.

Impact of treatment with metformin in comparison with insulin in gestational diabetes in libyan population a randomized controlled study

Background:

The aim of this study was the comparison of the glycemic control and maternal outcomes in women affected with gestational diabetes mellitus (GDM) managed with metformin versus insulin.

Materials and Methods:

The participants included in this study were 140 women diagnosed with GDM. They were randomized into two groups, women included in the first group were treated with metformin and the women of the second group were managed with insulin.

Results:

The glycemic control was similar in both the treatment arms and the only noteworthy difference was found in the mean fasting blood glucose, which was significantly higher in the women receiving insulin as compared to the women receiving metformin. There were no substantial differences in the maternal outcome with the use of metformin compared to insulin in women with GDM.

Conclusion:

The incidence of operative delivery was higher in metformin-treated group, whereas the hospital admission rate was considerably elevated in insulin-treated group.

The Effect of Mild Gestational Diabetes Mellitus Treatment on Adverse Pregnancy Outcomes: A Systemic Review and Meta-Analysis

OBJECTIVES

It is uncertain whether the treatment of mild gestational diabetes mellitus (GDM) improves pregnancy outcomes. The aim of this systemic review and meta-analysis was to investigate the effect of mild GDM treatment on adverse pregnancy outcomes.

METHODS

A comprehensive literature search was conducted on the databases of PubMed, Scopus, and Google Scholar to retrieve studies that compared interventions for the treatment of mild GDM with usual antenatal care. The fixed/random effects models were used for the analysis of heterogeneous and non-heterogeneous results. Publication bias was assessed using the Harbord test. Also, the DerSimonian and Laird, and inverse variance methods were used to calculate the pooled odds ratio of events. The quality assessment of the included studies was performed using the Modified Newcastle-Ottawa Quality Assessment scale and the CONSORT checklist. In addition, the risk of bias was evaluated using the Cochrane Collaboration's tool for assessing risk of bias.

RESULTS

The systematic review and meta-analysis involved ten studies consisting of 3317 pregnant women who received treatment for mild GDM and 4407 untreated counterparts. Accordingly, the treatment of mild GDM significantly reduced the risk of macrosomia (OR = 0.3; 95%CI = 0.3-0.4), large for gestational age (OR = 0.4; 95%CI = 0.3-0.5), shoulder dystocia (OR = 0.3; 95%CI = 0.2-0.6), caesarean-section (OR = 0.8; 95%CI = 0.7-0.9), preeclampsia (OR = 0.4; 95%CI = 0.3-0.6), elevated cord C-peptide (OR = 0.7; 95%CI = 0.6-0.9), and respiratory distress syndrome (OR = 0.7; 95%CI = 0.5-0.9) compared to untreated counterparts. Moreover, the risk of induced labor significantly increased in the treated group compared to the untreated group (OR = 1.3; 95%CI = 1.0-1.6). However, no statistically significant difference was observed between the groups in terms of small for gestational age, hypoglycemia, hyperbilirubinemia, birth trauma, admission to the neonatal intensive care unit, and preterm birth. Sensitivity analysis based on the exclusion of secondary analysis data was all highly consistent with the main data analysis.

CONCLUSION

Treatment of mild GDM reduced the risk of selected important maternal outcomes including preeclampsia, macrosomia, large for gestational age, cesarean section, and shoulder dystocia without increasing the risk of small for gestational age. Nevertheless, the treatment could not reduce the risk of neonatal metabolic abnormalities or several complications in newborn.

Compromised barrier integrity of human feto-placental vessels from gestational diabetic pregnancies is related to downregulation of occludin expression

AIMS/HYPOTHESIS

Reduced occupancy of junctional occludin is a feature of human placental vessels in the diabetic milieu. However, the functional consequence of this and whether this loss is due to differential expression of occludin splice variants is not known. Our study aimed to investigate the effects of gestational diabetes mellitus (GDM), and its treatment, on endothelial junctional integrity, gene and protein expression of occludin splice variants, and potential regulation of expression by microRNAs (miRNAs).

METHODS

Term placentas were obtained from normal pregnancies (n = 21), and pregnancies complicated by GDM where glucose levels were controlled by diet (n = 11) or metformin (n = 6). Gene and microRNA (miRNA) expression were determined by quantitative real-time PCR; protein expression by immunoblotting; endothelial junctional occupancy by fluorescence microscopy and systematic sampling; and paracellular leakage by perfusion of placental microvascular beds with 76 M_r dextran. Transfection studies of miRNAs that target OCLN were performed in HUVECs, and the trans-endothelial electrical resistance and tracer permeability of the HUVECs were measured.

RESULTS

All three predicted OCLN gene splice variants and two occludin protein isoforms were found in human placental samples. In placental samples from diet-controlled GDM (d-GDM) pregnancies we found a lower percentage of conduit vessels showing occludin immunoreactivity (12%, p < 0.01), decreased levels of the fully functional occludin isoform-A protein (29%), and differential gene expression of OCLN variant 2 (33% decrease), variant 3 (3.3-fold increase). These changes were not seen in samples from the group with metformin-controlled GDM. In d-GDM placentas, increased numbers of conduit microvessels demonstrated extravasation of 76 M_r dextran (2.0-fold). In d-GDM expression of one of the five potential miRNAs targeting OCLN, miR-181a-5p, expression was 2.1-fold that in normal pregnancies. Experimental overexpression of miR-181a-5p in HUVECs from normal pregnancies resulted in a highly significant downregulation of OCLN variant 1 (69%) and variant 2 (46%) gene expression, with decreased trans-endothelial resistance (78%) and increase in tracer permeability (1.3-fold).

CONCLUSIONS/INTERPRETATION

Downregulation of expression of OCLN variant 2 and the fully functional occludin isoform-A protein are a feature of placentas in d-GDM pregnancies. These may be behind the loss of junctional occludin and the increased extravasation of exogenous dextran observed. miR-181a-5p was in part responsible for the downregulation of occludin in placentas from d-GDM pregnancies. Induced overexpression of miR-181a-5p compromised the integrity of the endothelial barrier. Our data suggest that, despite good glucose control, the adoption of lifestyle changes alone during a GDM pregnancy may not be enough to prevent an alteration in the expression of occludin and the subsequent functional consequences in placentas and impaired vascular barrier function in offspring. Graphical abstract.

Current Researches, Rationale, Plausibility, and Evidence Gaps on Metformin for the Management of Hypertensive Disorders of Pregnancy

Hypertensive disorders of pregnancy (HDP) are a group of morbid pregnancy complications, with preeclampsia (PE) being the most common subclassification among them. PE affects 2%–8% of pregnancies globally and threatens maternal and fetal health seriously. However, the only effective treatment of PE to date is the timely termination of pregnancy, albeit with increased perinatal risks. Hence, more emerging therapies for PE management are in urgent need. Originally introduced as the first-line therapy for type 2 diabetes mellitus, metformin (MET) has now been found in clinical trials to significantly reduce the incidence of gestational hypertension and PE in pregnant women with PE-related risks, including but not limited to pregestational diabetes mellitus, gestational diabetes mellitus, polycystic ovary syndrome, or obesity. Additionally, existing clinical data have preliminarily ensured the safety of taking MET during human pregnancies. Relevant lab studies have indicated that the underlying mechanism includes angiogenesis promotion, endothelial protection, anti-inflammatory effects, and particularly protective effects on trophoblast cells against the risk factors, which are beneficial to placental development. Together with its global availability, easy administration, and low cost, MET is expected to be a promising option for the prevention and treatment of PE. Nevertheless, there are still some limitations in current studies, and the design of the relevant research scheme is supposed to be further improved in the future. Herein, we summarize the relevant clinical and experimental researches to discuss the rationale, safety, and feasibility of MET for the management of HDP. At the end of the article, gaps in current researches are proposed. Concretely, experimental MET concentration and PE models should be chosen cautiously. Besides, the clinical trial protocol should be further optimized to evaluate the reduction in the prevalence of PE as a primary endpoint. All of those evidence gaps may be of guiding significance to improve the design of relevant experiments and clinical trials in the future.

Serum lipids and their association with birth weight in metformin and insulin treated patients with gestational diabetes

AIMS

To compare the effects of metformin and insulin treatment on maternal serum lipids in patients with gestational diabetes (GDM), and to analyse the associations between individual lipids and birth weight (BW).

METHODS

This is a secondary analysis of a randomized trial comparing metformin (n = 110) and insulin (n = 107) treatment of GDM. Fasting serum lipidome was measured at baseline (the time of diagnosis, mean 30 gestational weeks, gw) and at 36 gw using nuclear magnetic resonance spectroscopy.

RESULTS

Total and VLDL triglycerides, and VLDL cholesterol increased from baseline to 36 gw in both treatment groups. The rise in triglycerides was greater in the metformin treated patients (p < 0.01). Baseline total and VLDL triglycerides, VLDL cholesterol, and apolipoprotein B to A-1 ratio (apoB/apoA-1) associated positively with BW, more strongly in the metformin group. Among patients in the highest baseline VLDL cholesterol or apoB/apoA-1 quartile, those treated with insulin had lower BWs than those treated with metformin (p < 0.03).

CONCLUSION

Compared to insulin, metformin treatment of GDM led to higher maternal serum concentrations of triglyceride-rich lipoproteins. Especially triglycerides and cholesterol in VLDL were positively associated with BW. Women with high VLDL cholesterol or high apoB/apoA-1 may benefit from insulin treatment over metformin with respect to offspring BW.

Gestational diabetes mellitus: Prevention, diagnosis and treatment. A fresh look to a busy corner

BACKGROUND

Gestational diabetes mellitus (GDM) is a common pregnancy complication characterized by hyperglycaemia with onset or first recognition during pregnancy. Risk factors include family history of diabetes, previous GDM, genetic predisposition for GDM/type 2 diabetes, insulin resistance conditions such as overweight, obesity and ethnicity. Women with GDM are at high risk for fetal macrosomia, small for gestational age, neonatal hypoglycaemia, operative delivery and caesarean delivery. The aim of this narrative review is to summarize the most recent findings of diagnosis and treatment of GDM in order to underline the importance to promote adequate prevention of this disease, especially through lifestyle interventions such as diet and physical activity.

METHODS

The research was conducted using the following electronic databases, MEDLINE, EMBASE, Web of Science, Scopus, ClinicalTrial.gov, OVID and Cochrane Library, including all published randomized and non-randomized studies as well as narrative and systematic reviews.

RESULTS

The lack of universally accepted criteria makes the definition of diagnosis and prognosis of this condition difficult. Early diagnosis and glucose blood level control may improve maternal and fetal short and long-term outcomes. Treatment strategies include nutritional interventions and exercise. Medical treatment can be necessary if these strategies are not effective. Moreover, novel non-pharmacologic agents such as myo-inositol seem to be effective and safe both in the prevention and the treatment of GDM.

CONCLUSIONS

It is important to promote adequate prevention of GDM. Further studies are needed in order to better define the most appropriate strategies for the clinical management of women affected by GDM.