Outcomes in children of women with type 2 diabetes exposed to metformin versus placebo during pregnancy (MiTy Kids): a 24-month follow-up of the MiTy randomised controlled trial

Reproductive outcomes in female mice offspring due to maternal metformin treatment

AIMS

Metformin has shown beneficial effects on reproduction in women. However, its use during pregnancy remains controversial, as metformin can cross the placenta. Most studies have focused on the metabolic impact on the offspring of treated mothers, with limited information regarding its reproductive effects. The aim of this study was to evaluate potential alterations in ovarian function and fertility in female offspring of mothers treated with metformin during pregnancy and lactation.

MATERIALS AND METHODS

C57BL/6 female mice were treated with metformin four weeks before mating, and the treatment was maintained during gestation and lactation. Seven weeks after weaning, metabolic parameters as well as ovarian and reproductive function of the offspring were analyzed.

KEY FINDINGS

The offspring of treated mothers were lighter at birth and, in adulthood, they had more gonadal adipose tissue with no alterations in body weight. No changes in glucose metabolism were observed. Their follicular development was modified, with more early antral and atretic follicles and less primary and late antral follicles. Anti-Müllerian hormone expression and ovarian angiogenesis were increased. The estrous cycle, hormonal production and fertility were not affected by metformin exposure, however, the F2 generation showed higher body weight at birth.

SIGNIFICANCE

Metformin can induce fetal programming in animals exposed to it during development, impacting metabolism and ovarian functionality in adulthood. Under physiological conditions, these alterations do not result in reduced fertility or endocrine disruptions. Our data warrant studies in women to make informed decisions regarding metformin administration during critical developmental periods in clinical settings.

Intrauterine metformin exposure and adiposity outcomes in children: a systematic review and meta-analysis

OBJECTIVE

The study aims to assess the effect of intrauterine metformin exposure on offspring adiposity measures in childhood.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase and Cochrane Central were searched from inception to 4 October 2024.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Follow-up studies of randomised-controlled trials and observational studies involving metformin use in pregnancy for any insulin-resistant maternal condition were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data and completed risk-of-bias assessments using either Cochrane Risk-Of-Bias tool V.2 or Risk of Bias in Non-Randomised Studies of Exposure depending on study design. Meta-analyses were conducted using the generic inversed variance method in a random-effects model. Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess certainty of evidence.

RESULTS

18 studies reporting on 7975 children with metformin exposure in utero and over 1 million children without metformin exposure were included. At the oldest age of follow-up reported (weighted mean age of 4.4 years), children with metformin exposure for any maternal indication had comparable body mass index (BMI) with their non-exposed peers (standardised mean difference (SMD) -0.02; 95% CI: -0.11, 0.07; low certainty). When stratified by age at follow-up, while metformin-exposed children had slightly higher BMI at 1-3 years of age (SMD 0.15; 95% CI: 0.04, 0.27; low certainty), no difference remained between the two groups by ages 3-6 and 6-11 years. When stratified by maternal diagnosis, no difference in BMI was found in the diabetes and obesity subgroups, while in the polycystic ovary syndrome subgroup metformin-exposed children were heavier than non-exposed peers (SMD 0.31; 95% CI: 0, 0.62; low certainty). No difference was seen in overweight, obesity or waist circumference.

CONCLUSIONS

Metformin-exposed children did not differ in adiposity measures compared with their non-exposed peers in later childhood. This adds to the growing body of evidence supporting the long-term safety of metformin use in pregnancy.

PROSPERO REGISTRATION NUMBER

CRD42023394464.

Is metformin safe in pregnancy: a focus on offspring outcomes

INTRODUCTION

Metformin has been part of treatment algorithms for type 2 diabetes mellitus (T2DM) for decades. While it has formal approval in the U.S.A. for treatment of T2DM, it is used off-label in gestational diabetes mellitus (GDM), polycystic ovarian syndrome (PCOS), and ovarian hyperstimulation prevention. Its role as an insulin sensitizer has made it an attractive therapeutic to address the insulin resistance seen in these syndromes. In 2022, the European Union approved metformin as the only oral antidiabetic medication for diabetes in pregnancy. While its safety and benefits for the mother are well documented, it does cross the placenta with plasma concentrations comparable between mother and child at delivery.

AREAS COVERED

This special report will focus on major randomized control trials investigating metformin use in pregnancies impacted by PCOS, GDM, T2DM, and obesity and their offspring follow-up trials.

EXPERT OPINION

For the mother, metformin can be beneficial, with reduction in insulin therapeutic burden, weight gain, hypoglycemia and in certain situations, pre-eclampsia. For the neonate, benefits may include reduction in hypoglycemia and no increased risk of congenital anomalies. It is the long-term data in the offspring that remains unknown with some areas of concerns (SGA, altered anthropometrics) requiring continued research.

American Diabetes Association Professional Practice Committee, ElSayed NA, McCoy RG, Aleppo G, Balapattabi K, Beverly EA, Briggs Early K, Bruemmer D, Echouffo-Tcheugui JB, Ekhlaspour L, Garg R, Khunti K, Lal R, Lingvay I, Matfin G, Pandya N, Pekas EJ, Pilla SJ, Polsky S, Segal AR, Seley JJ, Stanton RC, Bannuru RR. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2025

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Update on the therapeutic role of metformin in the management of polycystic ovary syndrome: Effects on pathophysiologic process and fertility outcomes

Influential guidelines have supported the role of metformin in the management of polycystic ovary syndrome (PCOS) for a number of years. However, regulatory approvals for this therapeutic indication are still exceptional and exist only in a few countries, including for the originator, Glucophage®. PCOS is an insulin-resistant state, which drives hyperandrogenism and anovulatory infertility. The metabolic action of metformin involves amelioration of insulin resistance, which helps to resolve hormonal and metabolic disturbances and increases ovulation, pregnancy, and live birth rates relative to placebo. A combination of metformin with clomifene citrate (another widely used treatment for PCOS) is more effective than either alone and is a useful option in women with clomifene-resistant PCOS. Combining metformin with letrozole (1st-line agent for ovulation induction in women with PCOS and no other infertility risk factors) is not more effective than letrozole alone. Continuing metformin to the end of the 1st trimester at an effective dose (e.g. 1000-2000 mg/day) may help to reduce the rate of miscarriages. Metformin also has an adjunctive role in women with PCOS receiving assisted reproduction technology (ART) using the long gonadotrophin-releasing hormone agonist protocol, where it appears to increase the pregnancy rate and to reduce the risk of ovarian hyperstimulation syndrome. There is no role for metformin in women receiving short ART protocols. Where a successful pregnancy is achieved, metformin is generally safe for the mother and neonate. Further research is needed to define with greater precision the optimal dosage and times to initiate and discontinue metformin in women with PCOS who achieve pregnancy.

Treatment of Diabetes in Pregnancy With Metformin

Metformin is a commonly used drug in the treatment of type 2 diabetes and has been used to treat gestational diabetes since the 1970s. In pregnancy, its proven benefits include reduced gestational weight gain and reduced fetal size; some studies have shown reduced risk of cesarean delivery and lower rates of hypertension. Metformin can reduce the need for insulin therapy but does not eliminate such need in many patients. Despite these benefits, metformin crosses the placenta and has been associated with increases in the risk of giving birth to small-for-gestational-age neonates in some studies of individuals with type 2 diabetes in pregnancy. In addition, higher body mass index (BMI) z-scores have been observed among exposed offspring in some of the long-term follow-up studies. Nevertheless, metformin's low cost, ease of administration, and global reach make it a reasonable intervention in a population affected by rising rates of obesity and diabetes in pregnancy. Further follow-up studies are required to monitor the long-term health of exposed offspring.

Metformin use and preeclampsia risk in women with diabetes: a two-country cohort analysis

BACKGROUND

Metformin is a hypoglycaemic medication that has been proposed to treat or prevent preeclampsia. Combining national birth data from Scotland and Sweden, we investigated whether metformin used during pregnancy was associated with an altered risk of developing a hypertensive disorder of pregnancy.

METHODS

We utilised data from two population-based cohorts: Scotland (2012-2018) and Sweden (2007-2019). Nulliparous women with gestational diabetes or type 2 diabetes who had birth outcome data linked with medications prescribed during pregnancy were included. The association between metformin prescription and hypertensive disorders of pregnancy was characterised using inverse probability weighted regression analysis, adjusting for variables that predict metformin use and potential confounders. Adverse neonatal outcomes were included as secondary outcomes. Results from both countries were then combined in a meta-analysis using a random effects model.

RESULTS

The Scottish cohort included 3859 women with gestational diabetes or type 2 diabetes. Of these women, 30.8% (n = 1187) received at least one metformin prescription during pregnancy. For Sweden, 7771 women with gestational diabetes were included where 19.3% (1498) used metformin during pregnancy. Metformin prescription was not associated with an altered risk of any hypertensive disorder of pregnancy (Scotland adjusted relative risk (aRR) 0.88 [95% confidence interval (CI) 0.66-1.19]; Sweden aRR 1.08 [95% CI 0.86-1.37]) or preeclampsia (Scotland aRR 1.02 [95% CI 0.66-1.60]; Sweden aRR 1.00 [95% CI 0.72-1.39]). Combining adjusted results in a meta-analysis produced similar findings, with a pooled RR of 0.98 (95% CI 0.79-1.18) for any hypertensive disorder and RR 1.01 ([95% CI 0.73-1.28]) for preeclampsia. For neonatal outcomes, metformin was associated with a reduced risk of birthweight > 4500 g in Scotland (aRR 0.39 [95% CI 0.21-0.71]) but not in Sweden. There was no association between metformin and preterm birth or birthweight < 3rd or < 10th percentiles. Pooling results from both countries, metformin was not associated with adverse neonatal outcomes, including preterm birth (RR 1.00 [95% CI 0.89-1.13]), and birthweight < 10th percentile (RR 0.82 [95% CI 0.60-1.13]) or < 3rd percentile (RR 0.78 [95% CI 0.41-1.48]).

CONCLUSIONS

In this two-country analysis, metformin use in pregnancy among women with diabetes was not associated with an altered risk of developing any hypertensive disorder of pregnancy. In the combined meta-analysis, metformin was not associated with an altered risk of adverse neonatal outcomes.

Can short- and long-term maternal and infant risks linked to hypertension and diabetes during pregnancy be reduced by therapy?

Hypertensive disorders of pregnancy (HDP), especially preeclampsia, and diabetes during pregnancy pose significant risks for both maternal and infant health, extending to long-term outcomes such as early-onset cardiovascular disease and metabolic disorders. Current strategies for managing HDP focus on screening, prevention, surveillance, and timely intervention. No disease-modifying therapies exist so far for established preeclampsia; delivery remains the definitive resolution. Preventive measures-including early pregnancy screening, exercise, and low-dose aspirin-show promise. Antihypertensive treatments reduce severe hypertension risks, whereas magnesium sulfate remains the standard for preventing eclampsia. Planned delivery from gestational week 37 can balance maternal benefits and neonatal risks in women with established preeclampsia. Delivery between 34 and 37 weeks gestation in women with preeclampsia has to balance risks for mother and infant. Lifestyle interventions-particularly diet and physical activity-are pivotal in managing gestational diabetes mellitus and type 2 diabetes. The oral antidiabetic metformin has shown benefits in glycaemic control and reducing maternal weight gain, although its long-term effects on offspring remain uncertain. The safety of other peroral antidiabetics in pregnancy is less studied. Advancements in glucose monitoring and insulin administration present encouraging prospects for enhancing outcomes in women with diabetes types 1 and 2. Both HDP and diabetes during pregnancy necessitate vigilant management through a combination of lifestyle modifications, pharmacological interventions, and timely obstetric care. Although certain treatments such as low-dose aspirin and metformin show efficacy in risk reduction, further research is ongoing to ensure safety for both mothers and their offspring to reduce short- and long-term adverse effects.

Initiation of metformin in early pregnancy results in fetal bioaccumulation, growth restriction, and renal dysmorphology in a primate model

BACKGROUND

In recent years, pragmatic metformin use in pregnancy has stretched to include prediabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and (most recently) preeclampsia. However, with its expanded use, concerns of unintended harm have been raised.

OBJECTIVE

This study developed an experimental primate model and applied ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry for direct quantitation of maternal and fetal tissue metformin levels with detailed fetal biometry and histopathology.

STUDY DESIGN

Within 30 days of confirmed conception (defined as early pregnancy), 13 time-bred (timed-mated breeding) Rhesus dams with pregnancies designated for fetal necropsy were initiated on twice-daily human dose-equivalent 10 mg/kg metformin or vehicle control. Pregnant dams were maintained as pairs and fed either a control chow or 36% fat Western-style diet. Metformin or placebo vehicle control was delivered in various treats while the animals were separated via a slide. A cesarean delivery was performed at gestational day 145, and amniotic fluid and blood were collected, and the fetus and placenta were delivered. The fetus was immediately necropsied by trained primate center personnel. All fetal organs were dissected, measured, sectioned, and processed per clinical standards. Fluid and tissue metformin levels were assayed using validated ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry in selected reaction monitoring against standard curves.

RESULTS

Among 13 pregnancies at gestational day 145 with fetal necropsy, 1 dam and its fetal tissues had detectable metformin levels despite being allocated to the vehicle control group (>1 μmol metformin/kg maternal weight or fetal or placental tissue), whereas a second fetus allocated to the vehicle control group had severe fetal growth restriction (birthweight of 248.32 g [<1%]) and was suspected of having a fetal congenital condition. After excluding these 2 fetal pregnancies from further analyses, 11 fetuses from dams initiated on either vehicle control (n=4: 3 female and 1 male fetuses) or 10 mg/kg metformin (n=7: 5 female and 2 male fetuses) were available for analyses. Among dams initiated on metformin at gestational day 30 (regardless of maternal diet), significant bioaccumulation within the fetal kidney (0.78-6.06 μmol/kg; mean of 2.48 μmol/kg), liver (0.16-0.73 μmol/kg; mean of 0.38 μmol/kg), fetal gut (0.28-1.22 μmol/kg; mean of 0.70 μmol/kg), amniotic fluid (0.43-3.33 μmol/L; mean of 1.88 μmol/L), placenta (0.16-1.00 μmol/kg; mean of 0.50 μmol/kg), fetal serum (0.00-0.66 μmol/L; mean of 0.23 μmol/L), and fetal urine (4.10-174.10 μmol/L; mean of 38.5 μmol/L) was observed, with fetal levels near biomolar equivalent to maternal levels (maternal serum: 0.18-0.86 μmol/L [mean of 0.46 μmol/L]; maternal urine: 42.60-254.00 μmol/L [mean of 149.30 μmol/L]). Western-style diet feeding neither accelerated nor reduced metformin bioaccumulations in maternal or fetal serum, urine, amniotic fluid, placenta, or fetal tissues. In these 11 animals, fetal bioaccumulation of metformin was associated with less fetal skeletal muscle (57% lower cross-sectional area of gastrocnemius) and decreased liver, heart, and retroperitoneal fat masses (P<.05), collectively driving lower delivery weight (P<.0001) without changing the crown-rump length. Sagittal sections of fetal kidneys demonstrated delayed maturation, with disorganized glomerular generations and increased cortical thickness. This renal dysmorphology was not accompanied by structural or functional changes indicative of renal insufficiency.

CONCLUSION

Our study demonstrates fetal bioaccumulation of metformin with associated fetal growth restriction and renal dysmorphology after maternal initiation of the drug within 30 days of conception in primates. Given these results and the prevalence of metformin use during pregnancy, additional investigation of any potential immediate and enduring effects of prenatal metformin use is warranted.

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.

American Diabetes Association Professional Practice Committee, ElSayed NA, Aleppo G, Bannuru RR, Bruemmer D, Collins BS, Ekhlaspour L, Hilliard ME, Johnson EL, Khunti K, Lingvay I, Matfin G, McCoy RG, Perry ML, Pilla SJ, Polsky S, Prahalad P, Pratley RE, Segal AR, Seley JJ, Stanton RC, Gabbay RA. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Drug Therapies for Diabetes

The treatment of type 2 diabetes (T2D) necessitates a multifaceted approach that combines behavioral and pharmacological interventions to mitigate complications and sustain a high quality of life. Treatment encompasses the management of glucose levels, weight, cardiovascular risk factors, comorbidities, and associated complications through medication and lifestyle adjustments. Metformin, a standard in diabetes management, continues to serve as the primary, first-line oral treatment across all age groups due to its efficacy, versatility in combination therapy, and cost-effectiveness. Glucagon-like peptide-1 receptor agonists (GLP-1 RA) offer notable benefits for HbA1c and weight reduction, with significant cardiovascular benefits. Sodium-glucose cotransporter inhibitors (SGLT-2i) lower glucose levels independently of insulin while conferring notable benefits for cardiovascular, renal, and heart-failure outcomes. Combined therapies emphasizing early and sustained glycemic control are promising options for diabetes management. As insulin therapy remains pivotal, metformin and non-insulin agents such as GLP-1 RA and SGLT-2i offer compelling options. Notably, exciting novel treatments like the dual GLP-1/ glucose-dependent insulinotropic polypeptide (GIP) agonist show promise for substantially reducing glycated hemoglobin and body weight. This comprehensive review highlights the evolving landscape of pharmacotherapy in diabetes, the drugs currently available for treating diabetes, their effectiveness and efficacy, the impact on target organs, and side effects. This work also provides insights that can support the customization of treatment strategies.

Antidiabetic Therapy during Pregnancy: The Prescription Pattern in Italy

Pregestational and gestational diabetes mellitus are relevant complications of pregnancy, and antidiabetic drugs are prescribed to obtain glycemic control and improve perinatal outcomes. The objective of this study was to describe the prescription pattern of antidiabetics before, during and after pregnancy in Italy and to evaluate its concordance with the Italian guideline on treatment of diabetes mellitus. A multi-database cross-sectional population study using a Common Data Model was performed. In a cohort of about 450,000 women, the prescribing profile of antidiabetics seemed to be in line with the Italian guideline, which currently does not recommend the use of oral antidiabetics and non-insulin injection, even if practice is still heterogeneous (up to 3.8% in the third trimester used oral antidiabetics). A substantial variability in the prescription pattern was observed among the Italian regions considered: the highest increase was registered in Tuscany (4.2%) while the lowest was in Lombardy (1.5%). Women with multiple births had a higher proportion of antidiabetic prescriptions than women with singleton births both in the preconception period and during pregnancy (1.3% vs. 0.7%; 3.4% vs. 2.6%) and used metformin more frequently. The consumption of antidiabetics in foreign women was higher than Italians (second trimester: 1.8% vs. 0.9%, third trimester: 3.6% vs. 1.8%).

The metabolic response of human trophoblasts derived from term placentas to metformin

AIMS/HYPOTHESIS

Metformin is increasingly used therapeutically during pregnancy worldwide, particularly in the treatment of gestational diabetes, which affects a substantial proportion of pregnant women globally. However, the impact on placental metabolism remains unclear. In view of the association between metformin use in pregnancy and decreased birthweight, it is essential to understand how metformin modulates the bioenergetic and anabolic functions of the placenta.

METHODS

A cohort of 55 placentas delivered by elective Caesarean section at term was collected from consenting participants. Trophoblasts were isolated from the placental samples and treated in vitro with clinically relevant doses of metformin (0.01 mmol/l or 0.1 mmol/l) or vehicle. Respiratory function was assayed using high-resolution respirometry to measure oxygen concentration and calculated [Formula: see text]. Glycolytic rate and glycolytic stress assays were performed using Agilent Seahorse XF assays. Fatty acid uptake and oxidation measurements were conducted using radioisotope-labelled assays. Lipidomic analysis was conducted using LC-MS. Gene expression and protein analysis were performed using RT-PCR and western blotting, respectively.

RESULTS

Complex I-supported oxidative phosphorylation was lower in metformin-treated trophoblasts (0.01 mmol/l metformin, 61.7% of control, p<0.05; 0.1 mmol/l metformin, 43.1% of control, p<0.001). The proton efflux rate arising from glycolysis under physiological conditions was increased following metformin treatment, up to 23±5% above control conditions following treatment with 0.1 mmol/l metformin (p<0.01). There was a significant increase in triglyceride concentrations in trophoblasts treated with 0.1 mmol/l metformin (p<0.05), particularly those of esters of long-chain polyunsaturated fatty acids. Fatty acid oxidation was reduced by ~50% in trophoblasts treated with 0.1 mmol/l metformin compared with controls (p<0.001), with no difference in uptake between treatment groups.

CONCLUSIONS/INTERPRETATION

In primary trophoblasts derived from term placentas metformin treatment caused a reduction in oxidative phosphorylation through partial inactivation of complex I and potentially by other mechanisms. Metformin-treated trophoblasts accumulate lipids, particularly long- and very-long-chain polyunsaturated fatty acids. Our findings raise clinically important questions about the balance of risk of metformin use during pregnancy, particularly in situations where the benefits are not clear-cut and alternative therapies are available.

An unwelcome inheritance: childhood obesity after diabetes in pregnancy

Diabetes in pregnancy affects 20 million women per year and is associated with increased risk of obesity in offspring, leading to insulin resistance and cardiometabolic disease. Despite the substantial public health ramifications, relatively little is known about the pathophysiological mechanisms underlying obesity in these high-risk children, which creates a barrier to successful intervention. While maternal glucose itself is undeniably a major stimulus upon intrauterine growth, the degree of offspring hyperinsulinism and disturbed lipid metabolism in mothers and offspring are also likely to be implicated in the disease process. The aim of this review is to summarise current understanding of the pathophysiology of childhood obesity after intrauterine exposure to maternal hyperglycaemia and to highlight possible opportunities for intervention. I present here a new unified hypothesis for the pathophysiology of childhood obesity in infants born to mothers with diabetes, which involves self-perpetuating twin cycles of pancreatic beta cell hyperfunction and altered lipid metabolism, both acutely and chronically upregulated by intrauterine exposure to maternal hyperglycaemia.

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.

Metformin: update on mechanisms of action and repurposing potential

Currently, metformin is the first-line medication to treat type 2 diabetes mellitus (T2DM) in most guidelines and is used daily by >200 million patients. Surprisingly, the mechanisms underlying its therapeutic action are complex and are still not fully understood. Early evidence highlighted the liver as the major organ involved in the effect of metformin on reducing blood levels of glucose. However, increasing evidence points towards other sites of action that might also have an important role, including the gastrointestinal tract, the gut microbial communities and the tissue-resident immune cells. At the molecular level, it seems that the mechanisms of action vary depending on the dose of metformin used and duration of treatment. Initial studies have shown that metformin targets hepatic mitochondria; however, the identification of a novel target at low concentrations of metformin at the lysosome surface might reveal a new mechanism of action. Based on the efficacy and safety records in T2DM, attention has been given to the repurposing of metformin as part of adjunct therapy for the treatment of cancer, age-related diseases, inflammatory diseases and COVID-19. In this Review, we highlight the latest advances in our understanding of the mechanisms of action of metformin and discuss potential emerging novel therapeutic uses.

Management of type 2 diabetes in pregnancy: a narrative review

The prevalence of type 2 diabetes (T2DM) at reproductive age is rising. Women with T2DM have a similarly high risk for pregnancy complications as pregnant women with type 1 diabetes. To reduce adverse pregnancy and neonatal outcomes, such as preeclampsia and preterm delivery, a multi-target approach is necessary. Tight glycemic control together with appropriate gestational weight gain, lifestyle measures, and if necessary, antihypertensive treatment and low-dose aspirin is advised. This narrative review discusses the latest evidence on preconception care, management of diabetes-related complications, lifestyle counselling, recommendations on gestational weight gain, pharmacologic treatment and early postpartum management of T2DM.

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.