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

Efficacy and safety of pharmacological treatments for gestational diabetes: a systematic review comparing metformin with glibenclamide and insulin

AIM

Gestational diabetes, characterized by impaired glucose tolerance occurring or diagnosed during pregnancy, is a significant public health concern. When lifestyle and dietary measures fail (30 % of women), insulin is the standard treatment. Oral antidiabetic agents, such as metformin (Glucophage) and glibenclamide, could provide a promising alternative. The aim here was to evaluate the effectiveness and safety of these treatments in gestational diabetes.

METHODS

This study is based on a systematic literature review. A keyword search for "metformin (Glucophage)," "glibenclamide," "pregnancy," and "gestational diabetes" was conducted in the PubMed and Google Scholar databases from 2013 to 2023.

RESULTS

A total of 45 studies were selected and analyzed. metformin (Glucophage) appears to offer a combination of effectiveness in glycemic control and maternal and neonatal safety. Compared to insulin, it reduces maternal weight gain, lowers maternal hypoglycemia rates, and shows a tendency to reduce gestational hypertension and preeclampsia. Additionally, infants born to mothers on metformin (Glucophage) are less likely to be macrosomic, experience fewer neonatal hypoglycemic episodes, and require fewer admissions to intensive care units. On the other hand, glibenclamide seems effective in glycemic control but is associated with higher rates of macrosomia and neonatal hypoglycemia.

CONCLUSION

Metformin (Glucophage) appears to be a promising alternative to insulin for treating gestational diabetes, while uncertainties remain regarding the safety of glibenclamide.

Oral Glucose-Lowering Agents vs Insulin for Gestational Diabetes: A Randomized Clinical Trial

Importance

Metformin and glyburide monotherapy are used as alternatives to insulin in managing gestational diabetes. Whether a sequential strategy of these oral agents results in noninferior perinatal outcomes compared with insulin alone is unknown.

Objective

To test whether a treatment strategy of oral glucose-lowering agents is noninferior to insulin for prevention of large-for-gestational-age infants.

Design, Setting, and Participants

Randomized, open-label noninferiority trial conducted at 25 Dutch centers from June 2016 to November 2022 with follow-up completed in May 2023. The study enrolled 820 individuals with gestational diabetes and singleton pregnancies between 16 and 34 weeks of gestation who had insufficient glycemic control after 2 weeks of dietary changes (defined as fasting glucose >95 mg/dL [>5.3 mmol/L], 1-hour postprandial glucose >140 mg/dL [>7.8 mmol/L], or 2-hour postprandial glucose >120 mg/dL [>6.7 mmol/L], measured by capillary glucose self-testing).

Interventions

Participants were randomly assigned to receive metformin (initiated at a dose of 500 mg once daily and increased every 3 days to 1000 mg twice daily or highest level tolerated; n = 409) or insulin (prescribed according to local practice; n = 411). Glyburide was added to metformin, and then insulin substituted for glyburide, if needed, to achieve glucose targets.

Main Outcomes and Measures

The primary outcome was the between-group difference in the percentage of infants born large for gestational age (birth weight >90th percentile based on gestational age and sex). Secondary outcomes included maternal hypoglycemia, cesarean delivery, pregnancy-induced hypertension, preeclampsia, maternal weight gain, preterm delivery, birth injury, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal intensive care unit admission.

Results

Among 820 participants, the mean age was 33.2 (SD, 4.7) years). In participants randomized to oral agents, 79% (n = 320) maintained glycemic control without insulin. With oral agents, 23.9% of infants (n = 97) were large for gestational age vs 19.9% (n = 79) with insulin (absolute risk difference, 4.0%; 95% CI, -1.7% to 9.8%; P = .09 for noninferiority), with the confidence interval of the risk difference exceeding the absolute noninferiority margin of 8%. Maternal hypoglycemia was reported in 20.9% with oral glucose-lowering agents and 10.9% with insulin (absolute risk difference, 10.0%; 95% CI, 3.7%-21.2%). All other secondary outcomes did not differ between groups.

Conclusions and Relevance

Treatment of gestational diabetes with metformin and additional glyburide, if needed, did not meet criteria for noninferiority compared with insulin with respect to the proportion of infants born large for gestational age.

Trial Registration

Netherlands Trial Registry Identifier: NTR6134.

Metformin and risk of adverse pregnancy outcomes among pregnant women with gestational diabetes in the United Kingdom: A population-based cohort study

AIMS

Metformin is increasingly used off-label as the treatment of gestational diabetes (GDM). Our objective was to determine if metformin versus insulin initiation is associated with the adverse pregnancy outcomes.

MATERIALS AND METHODS

We conducted a retrospective cohort study using data from the Clinical Practice Research Datalink, its pregnancy register, and Hospital Episode Statistics from 1998 to 2018. We included pregnancies of women who initiated metformin or insulin between 20 weeks gestation and pregnancy end. The primary outcome was a composite outcome of large for gestational age (LGA) and macrosomia. The secondary outcomes included small for gestational age (SGA), preterm birth, caesarean delivery, and hypertensive disorders during pregnancy (HDP). Inverse probability weighted-Cox proportional hazards models were to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CI), comparing those who initiated metformin versus insulin at cohort entry, accounting for baseline covariates.

RESULTS

Our cohort included pregnancies of 1297 women initiating metformin and of 895 women initiating insulin. Compared to insulin initiation, metformin initiation was associated with a decreased risk of LGA or macrosomia (HR 0.64, 95% CI 0.49, 0.78), Caesarean delivery (HR 0.83, 95% CI 0.69, 0.98), and preterm birth (HR 0.83, 95% CI 0.58, 1.08). The HRs for HDP and SGA were 0.92 (95% CI 0.57, 1.27) and 1.33 (95% CI 0.67, 2.00), respectively.

CONCLUSIONS

Our study suggests that, compared to initiating insulin, initiating metformin is associated with decreased risks of adverse pregnancy outcomes among women with GDM. These findings provide important real-world evidence regarding the use of metformin for GDM.

Metformin versus insulin in gestational diabetes mellitus: a systematic review

Objective

The aim of this study is to assess the use of metformin with or without insulin for the treatment of Gestational Diabetes Mellitus compared to insulin alone.

Data sources

This article consists of a systematic review of randomized clinical trials. The searches were carried out on MEDLINE including 7 studies, between 2010 to 2021.

Study selection

Randomized clinical trials comparing metformin and insulin written in English, Spanish or Portuguese, with no time limit, were included.

Data collection

Data was extracted from all the 7 articles and compared statistically when possible. Whenever data was not available or couldn't be statistically compared, the main results were described in detail.

Data synthesis

Insulin alone is not superior than metformin with or without insulin on gestational diabetes mellitus.

Conclusion

There is a potential viability of using metformin as an alternative compared to insulin alone in the treatment of Gestational Diabetes Mellitus. However, all assessed outcomes have a very low level of certainty of evidence and more studies are necessary to support these findings.

A meta-analysis of metformin and insulin on maternal outcome and neonatal outcome in patients with gestational diabetes mellitus

INTRODUCTION

The use of metformin for treating gestational diabetes mellitus (GDM) remains controversial because it can pass through the placenta. This meta-analysis aimed to compare the effects of metformin and insulin on maternal and neonatal outcomes in patients with GDM.

METHODS

We conducted a comprehensive search of the PubMed, Embase, and Cochrane Library databases, focusing on randomized controlled trials (RCTs) that evaluated the impacts of metformin and insulin on both maternal and neonatal outcomes in patients with GDM.

RESULTS

Twenty-four RCTs involving 4934 patients with GDM were included in this meta-analysis. Compared with insulin, metformin demonstrated a significant reduction in the risks of preeclampsia (RR 0.61, 95% CI 0.48 to 0.78, p < .0001), induction of labor (RR 0.90, 95% CI 0.82 to 0.98, p = .02), cesarean delivery (RR 0.91, 95% CI 0.85 to 0.98, p = .01), macrosomia (RR 0.67, 95% CI 0.53 to 0.83, p = .0004), neonatal intensive care unit (NICU) admission (RR 0.75, 95% CI 0.66 to 0.86, p < .0001), neonatal hypoglycemia (RR 0.55, 95% CI 0.48 to 0.63, p < .00001), and large for gestational age (LGA) (RR 0.80, 95% CI 0.68 to 0.94, p = .007). Conversely, metformin showed no significant impact on gestational hypertension (RR 0.84, 95% CI 0.67 to 1.06, p = .15), spontaneous vaginal delivery (RR 1.13, 95% CI 1.00 to 1.08, p = .05), emergency cesarean section (RR 0.94, 95% CI 0.77 to 1.16, p = .58), shoulder dystocia (RR 0.65, 95% CI 0.31 to 1.39, p = .27), premature birth (RR 0. 92, 95% CI 0.61 to 1.39, p = .69), polyhydramnios (RR 1.11, 95% CI 0.54 to 2.30, p = .77), birth trauma (RR 0.87, 95% CI 0.54 to 1.39, p = .56), 5-min Apgar score < 7 (RR 1.13, 95% CI 0.76 to 1.68, p = .55), small for gestational age (SGA) (RR 0.93, 95% CI 0.71 to 1.22, p = .62), respiratory distress syndrome (RDS) (RR 0.74, 95% CI 0.50 to 1.08, p = .11), jaundice (RR 1.09, 95% CI 0.95 to 1.25, p = .24) or birth defects (RR 0.80, 95% CI 0.37 to 1.74, p = .57).

CONCLUSIONS

The findings suggest that metformin can reduce the risk of certain maternal and neonatal outcomes compared with insulin therapy for GDM. However, long-term follow-up studies of patients with GDM taking metformin and their offspring are warranted to provide further evidence.

Maternal Fasting Plasma Glucose, Age and Body Mass Index as Prediction of Gestational Diabetes Mellitus in Iran

Background

Gestational diabetes mellitus (GDM) is a common complication of pregnancy that can lead to adverse outcomes. In this retrospective cohort study, maternal fasting blood sugar (FBS) in the second trimester of pregnancy, body mass index (BMI), and age were assessed as potential screening indicators of later GDM.

Methods

The study population included information on 4007 Iranian pregnant women documented by the Integrated Health Record System (SIB) record system (2019-2020).

Results

In the adjusted analysis, FBS maintained a significant relationship with GDM (P ≤0.001). In the simple ROC analysis, the AUC (SE) of FBS for the prediction of GDM was 0.905(0.09), and considering the cut-off point as 85.95, sensitivity (Se) and specificity (Sp) were equal to 0.81 and 0.71, respectively, but by stillbirth, abortion, prematurity, neonatal weight, height, and head circumference not obtained acceptable AUC (≥.60) for detection of FBS cut-off point. The cut-off point of FBS in the presence of maternal age (AUC>0.6) and BMI (AUC>0.6) by GDM was 83.75(Se= 86.4%, Sp= 80.0%).

Conclusion

Based on the evidence presented, maternal weight and BMI are important in predicting hyperglycemia leading to GDM. It is necessary to conduct more precise national studies to standardize the FBS cut-off point by controlling age and BMI variables.

Long-Term Impact on Offspring (5 to 11 Years of Age) of Metformin Use in Pregnancy in Mothers With Diabetes: A Systematic Review and Meta-Analysis

OBJECTIVE

Data are scant on the impact of metformin use in gestational diabetes mellitus/diabetes in pregnancy on long-term outcomes in children and mothers beyond 5 years of childbirth. This systematic review and meta-analysis aimed to evaluate the long-term impact of metformin use in pregnancy on children and their mothers.

METHODS

Electronic databases were searched for studies evaluating metformin compared with insulin for managing gestational diabetes mellitus/diabetes in pregnancy. The primary outcome was the change in body mass index (BMI) in children at the ages of 5 to 11 years. The secondary outcomes were alterations in other anthropometric measures, obesity, and changes in the levels of lipids and adipocytokines in children and mothers.

RESULTS

Children at the age of 9 years born to mothers who were treated with metformin during pregnancy had similar BMI (mean difference [MD], 1.09 kg/m2 [95% confidence interval {CI}, -0.44 to 2.62]; P = .16; I2 = 16%), waist circumference-to-height ratio (MD, 0.13 [95% CI, -0.05 to 0.30]; P = .16; I2 = 94%), dual-energy X-ray absorptiometry (DXA) total fat mass (MD, 0.68 kg [95% CI, -2.39 to 3.79]; P = .66; I2 = 70%), DXA total fat percent (MD, 0.04% [95% CI, -3.44 to 3.51]; P = .98; I2 = 56%), DXA total fat-free mass (MD, 0.81 kg [95% CI, -0.96 to 2.58]; P = .37; I2 = 55%), magnetic resonance imaging visceral adipose tissue volume (MD, 80.97 cm3 [95% CI, -136.47 to 298.41]; P = .47; I2 = 78%), and magnetic resonance spectroscopy liver fat percentage (MD, 0.27% [95% CI, -1.26 to 1.79]; P = .73; I2 = 0%) to those born to mothers who were treated with insulin. Serum adiponectin, leptin, alanine aminotransferase, and ferritin were comparable among groups. In children between the ages of 9 and 11 years, the occurrence of obesity, diabetes, or challenges in motor and social development were comparable between the 2 groups. After 9 years of childbirth, BMI and the risk of developing diabetes were similar between the 2 groups of women.

CONCLUSION

Metformin use in pregnancy did not show any adverse effects compared with insulin on long-term outcomes in children and their mothers.

Cardiometabolic outcomes in offspring of women treated with metformin versus insulin for gestational diabetes: A Systematic Review and meta-analysis

INTRODUCTION

Gestational diabetes mellitus (GDM) is commonly managed with either metformin or insulin, but their comparative effects on offspring cardiometabolic outcomes are not fully understood.

OBJECTIVE

To investigate the impact of metformin and insulin, two distinct pharmacological interventions, on cardiometabolic outcomes in offspring of mothers with GDM.

METHODOLOGY

Systematic literature review was performed for articles (randomized control trials) published from 1974 to May 2024 using a predefined search strategy. Studies were screened for title and abstract followed by full text. Quality assessment was done using a separate risk of bias tool in line with the PRISMA-2020 checklist.

RESULTS

Among 5463 records, five studies (metformin = 409 children or insulin n = 434 children) were included. Offspring of metformin-treated mothers in the age range of 5-9 years had more fat-free mass (kg) by bioimpedance and abdominal (subcutaneous and visceral) fat volume (cm3) by MRI. Fasting plasma glucose and triglycerides were lower in the metformin-treated group for offspring aged 5-9 years. No significant differences were observed for other cardiometabolic outcomes. Limited data available for offsprings less than 5 years of age precluded meta-analysis for the available outcomes, except for body weight, and difference for this was also not significant.

CONCLUSION

In short term no major differences has been seen in most of the cardiometabolic outcomes evaluated in the meta-analysis. Future trials with longer follow up are required and in different ethnicities.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO-CRD42023450990.

Management of Endocrinopathies During Pregnancy: A Systematic Review

Uncertainty surrounds the efficacy and security of several medications in treating endocrinopathies, such as gestational diabetes mellitus (GDM) in individuals whose normal glucose levels cannot be maintained by diet and exercise alone. To improve pregnancy results for GDM individuals, the present review is conducted to measure the effectiveness of several antidiabetic medications for glucose management. Up until 2024, we looked through PubMed and Google Scholar. Patients with GDM were enrolled in randomized controlled studies that examined several medications. Using the Cochrane risk of bias method, we obtained the pertinent data and evaluated the bias probability. To determine the odds ratio and the surface of the cumulative ranking function of the maternal and neonatal consequences of various therapies in GDM individuals, we first performed pair-wise meta-assessments and subsequently used a systematic review. Macrosomia, higher gestational ages, infant hypoglycemia, and birth weight are the neonatal outcomes. Glycohemoglobin (HbA1c), and pregnancy-induced hypertension (PIH) are the maternal outcomes. This thorough analysis of 25 trial designs found that metformin had fewer cases of macrosomia, higher gestational ages, infant hypoglycemia, and decreased birth weight when compared to glyburide. Metformin was found to be the fastest way to control blood sugar levels in individuals with GDM, whereas glyburide was found to be the most successful medicine for the same purpose.

An overview of diabetes mellitus in pregnant women with obesity

Rates of obesity are increasing world-wide with an estimated 1billion people projected to be obese by 2030 if current trends remain unchanged. Obesity currently considered one of the most significant associated factors of non-communicable diseases poses the greatest threat to health. Diabetes mellitus is an important metabolic disorder closely associated with obesity. It is therefore expected that with the increasing rates of obesity, the rates of diabetes in pregnancy will also be rising. This disorder may pre-date pregnancy (diagnosed or undiagnosed and diagnosed for the first time in pregnancy) or may be of onset in pregnancy. Irrespective of the timing of onset, diabetes in pregnancy is associated with both fetal and maternal complications. Outcomes are much better if control is maximised. Early diagnosis, multidisciplinary care and tailored management with optimum glycaemic control is associated with a significant reduction in not only pregnancy complications but long-term consequences on both the mother and offspring. This review brings together the current understanding of the pathogenesis of the endocrine derangements that are associated with diabetes in pregnancy how screening should be offered and management including pre-pregnancy care and the role of newer agents in management.

Changes in Oxidative Stress and Intestinal Permeability during Pregnancy in Women with Gestational Diabetes Mellitus Treated with Metformin or Insulin and Healthy Controls: A Randomized Controlled Trial

Both oxidative stress and intestinal permeability are increased in hyperglycemic situations and have been shown to be reduced by metformin in type 2 diabetes mellitus (T2DM) patients. The aim of this study was to elucidate the effect of metformin on oxidative stress and intestinal permeability in women with gestational diabetes mellitus (GDM) treated with metformin compared to those treated with insulin and healthy controls. A total of 120 women were included from August 2016 to February 2022: 41 received metformin (MET group), 38 received insulin (INS group), and 41 were healthy controls. Baseline and antenatal visits were carried out at 25.4 ± 4.8 and 36.1 ± 0.8 weeks of pregnancy, respectively. Advanced oxidation protein products (AOPPs), total antioxidant capacity (TAC), and zonulin levels were measured at every visit. Zonulin levels from baseline to prepartum visit increased significantly in both healthy controls (0.6 ± 0.9 to 1.2 ± 1.7 ng/mL, p = 0.004) and the INS group (0.4 ± 0.3 to 0.6 ± 0.5 ng/mL, p = 0.034) but did not significantly change in the MET group (0.4 ± 0.4 to 0.5 ± 0.4 ng/mL, p = 0.202). However, TAC and AOPP levels significantly increased in women with GDM, both in the INS and MET groups but not in the healthy controls. In conclusion, in our population, metformin has been shown to avoid an increase in intestinal permeability but failed to avoid an increase in oxidative stress related to hyperglycemia.

Case Report: Abruptio placentae and epileptic seizure after occurrence of perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis

Hypertriglyceridemia-induced acute pancreatitis seldom occurs in the second trimester of pregnancy with gestational diabetes mellitus. For these patients, the existing knowledge on concomitant hyperglycemia is not sufficient. We report a case of abruptio placentae and epileptic seizure following perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis. The occurrence of abruptio placentae and epileptic seizure may be associated with concomitant hyperglycemia, and the epileptic seizure was terminated after she underwent treatment with insulin. We should pay more attention to the adverse effects of perinatal hyperglycemia and continue to give appropriate insulin treatment even if patients have passed the acute phase of hypertriglyceridemia-induced acute pancreatitis.