Metformin for pregnancy and beyond: the pros and cons

Metformin use in women with polycystic ovary syndrome (PCOS): Opportunities, benefits, and clinical challenges

Metformin, a synthetic biguanide, is widely used to manage type 2 diabetes, and is commonly prescribed in polycystic ovary syndrome (PCOS) to address insulin resistance and associated metabolic and reproductive disturbances. PCOS is characterised by hormonal imbalances such as hyperandrogenism and anovulation, metabolic abnormalities including insulin resistance and increased cardiometabolic risk, and higher rates of pregnancy complications. However, the role of metformin in the multifaceted nature of PCOS remains debated. This review synthesises the mechanisms of action of metformin and its effects on metabolic, hormonal, reproductive, and pregnancy-related outcomes in PCOS. In non-pregnant women, metformin improves insulin resistance, menstrual regularity, and androgen levels, particularly in those with obesity or insulin resistance, and may enhance fertility when combined with other treatments. However, it is not effective as a first-line therapy for weight loss, ovulation induction, or treatment of clinical hyperandrogenic features, including hirsutism or acne. In pregnancy, metformin may reduce early pregnancy loss, miscarriage, and preterm birth, though findings for gestational diabetes and preeclampsia are inconsistent. Evidence is limited by study heterogeneity, varying diagnostic criteria, and the use of aggregate data in meta-analyses, all of which make interpretation challenging. Future research should prioritise well-powered clinical trials, individual patient data meta-analyses, and longer-term follow-up studies, particularly in pregnancy, to better define the populations most likely to benefit from metformin use across the PCOS spectrum. PLAIN LANGUAGE SUMMARY: Polycystic ovary syndrome (PCOS) is a common condition that affects up to 1 in 10 women of reproductive age. It is characterised by irregular or absent periods, signs of elevated male hormones (high androgens or excess hair growth), and/or polycystic ovaries seen on ultrasound. These features can lead to fertility problems, acne, psychological distress, and an increased risk of various disorders such as depression, type 2 diabetes and heart disease. Many women with PCOS also experience challenges during pregnancy, including a higher risk of miscarriage, preterm birth, and gestational diabetes. Metformin is a medication most often used to manage diabetes. In women with PCOS, it can help improve how the body responds to insulin, which may also reduce male hormone levels, improve menstrual cycles, and support fertility. This review examines the role of metformin in treating PCOS-both before and during pregnancy-by summarising key findings from the available evidence. In women who are not pregnant, metformin can help improve insulin resistance, hormone levels, and menstrual regularity, particularly among those who are overweight or have signs of insulin resistance. However, metformin alone is not a first-choice treatment for weight loss, ovulation problems, or symptoms such as acne and unwanted hair growth. When combined with other treatments, such as hormone therapy or fertility medications, it may offer additional benefits. During pregnancy, metformin is considered safe for use in women with PCOS and may lower the risk of early pregnancy loss and preterm birth. However, its effects on preventing gestational diabetes or high blood pressure are less clear, with mixed results across studies. Some research suggests that babies exposed to metformin in the womb may have slightly larger head sizes or a higher risk of being overweight in early childhood, but the long-term health effects remain unknown. Overall, metformin can be a helpful part of treatment for some women with PCOS, especially those with insulin resistance or certain pregnancy risks. Still, it is not a one-size-fits-all solution. More high-quality research is needed to better understand which women benefit most and to assess any long-term effects on children exposed to metformin during pregnancy.

GLP-1 receptor agonist therapy and pregnancy: Evolving and emerging evidence

The prevalence of type 2 diabetes mellitus (T2DM) and obesity is increasing in young adults, posing significant risks around pregnancy. Obesity also impacts on fertility and the co-existence of polycystic ovarian syndrome increases the prevalence of cardiovascular metabolic risk factors. There has been a renewed interest in glucagon-like peptide-1 receptor agonists (GLP-1RA) in this context, due to their multi-dimensional impact on the reproductive axis, as well as their ability to simultaneously target weight loss and glycaemic control. There is, however, limited availability of safety data with respect to these newer non-insulin-based diabetes medications from the perspective of fetal development. As GLP-1RA are not licensed for use in pregnancy, with the increasing chances of incidental exposure from pre-conception use for obesity and T2DM, it is imperative that pre-conception counselling should be an integral part of consultation prior to the initiation of these drugs.

Association of Myo-Inositol and Microlipodispersed Magnesium in Androgen-Dependent Dermatological Diseases: A Retrospective Study

Background: Acne is a pathology of the pilosebaceous unit. It is characterized by a highly complex etiopathology which includes inflammation, hyperkeratinization, increased sebum production, colonization of Cutibacterium acne, hyperandrogenemia, and hyperinsulinemia. This condition, together with hirsutism, androgenic alopecia, and acanthosis nigricans, are highly prevalent cutaneous manifestations of the polycystic ovary syndrome (PCOS). While conventional therapies represent effective treatment options, they are not free from side effects which may reduce compliance. In this context, considerable attention has been directed toward nutraceutical supplements, which include different molecules with great potential to reduce inflammation, hyperkeratinization, hyperseborrhea, and hyperinsulinemia. Myo-inositol has been shown to be effective in improving some of the signs and symptoms of patients with microcystic ovaries: reducing body mass index (BMI), testosterone free levels, dehydroepiandrosterone sulfate (DHEAS) levels, and improving ovarian function and insulin sensitivity. Methods: The authors conducted a retrospective study that included 200 patients suffering from PCOS. Over 6 months, they analyzed the effects of the supplementation of LEVIGON™ (Sanitpharma; Milan, Italy)-a specific nutraceutical formulation containing myo-inositol, microlipodispersed magnesium, and folic acid-on the clinical picture of acne and hirsutism. Results: The supplementation of LEVIGON™ showed a significant reduction of BMI, testosterone, testosterone free, and DHEAS levels, thus improving the clinical picture of acne and hirsutism. Moreover, the impact of acne on the quality of life, assessed using the Cardiff Acne Disability Index (CADI) and Dermatology Life Quality Index (DLQI) scale, improved significantly after 3 and 6 months. Women with hirsutism benefited also from a significant improvement of the Ferriman-Gallwey score after both 3 and 6 months (p < 0.0001; p < 0.0001 respectively compared to the baseline). Conclusions: Myo-inositol supplementation, associated with microlipodispersed magnesium in a bioaccessible form, proved to be extremely useful in reducing acne and hirsutism in patients suffering from microcystic ovaries. In addition, there were no side effects, thus confirming excellent compliance. Further long-term randomized clinical trials are needed to confirm this preliminary evidence.

The Anti-Aging Mechanism of Metformin: From Molecular Insights to Clinical Applications

Aging represents a complex biological phenomenon marked by the progressive deterioration of physiological functions over time, reduced resilience, and increased vulnerability to age-related diseases, ultimately culminating in mortality. Recent research has uncovered diverse molecular mechanisms through which metformin extends its benefits beyond glycemic control, presenting it as a promising intervention against aging. This review delves into the anti-aging properties of metformin, highlighting its role in mitochondrial energy modulation, activation of the AMPK-mTOR signaling pathway, stimulation of autophagy, and mitigation of inflammation linked to cellular aging. Furthermore, we discuss its influence on epigenetic modifications that underpin genomic stability and cellular homeostasis. Metformin's potential in addressing age-associated disorders including metabolic, cardiovascular, and neurodegenerative diseases is also explored. The Targeting Aging with Metformin (TAME) trial aims to provide key evidence on its efficacy in delaying aging in humans. Despite these promising insights, significant challenges persist in gaining a more comprehensive understanding into its underlying mechanisms, determining optimal dosing strategies, and evaluating long-term safety in non-diabetic populations. Addressing these challenges is crucial to fully realizing metformin's potential as an anti-aging therapeutic.

Metformin for Treating Gestational Diabetes: What Have We Learned During the Last Two Decades? A Systematic Review

There has been accumulating evidence over the past two decades that metformin can be an effective treatment for gestational diabetes mellitus (GDM) in women whose diet and exercise fail to attain optimal glycemic control. The objective of this review was to comprehensively analyze all studies investigating the effectiveness of metformin compared to insulin and other drugs utilized for the treatment of GDM. After a comprehensive literature review based on PRISMA 2020, 35 studies were included after a selection process utilizing predetermined inclusion and exclusion criteria. A variety of short-term maternal and neonatal outcomes were assessed. Metformin is a highly efficient medication for attaining optimal control of blood sugar levels in women with GDM, resulting in a significant reduction in the amount of weight gained during pregnancy. Regarding additional maternal outcomes, such as pregnancy-induced hypertension and cesarean deliveries, some studies demonstrate a link between metformin and a reduced occurrence of both conditions. In contrast, others do not find an association. Regarding short-term neonatal outcomes, metformin does not exhibit any changes in gestational age at delivery. In contrast, metformin demonstrated substantial decreases in the likelihood of greater gestational birth weight and neonatal hospitalization when compared to other drugs. When compared primarily to insulin, metformin decreases the probability of several short-term outcomes related to pregnancy and newborns. Additional data are necessary for extended follow-up studies, including patients with GDM treated with metformin.

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.

Polycystic ovary syndrome and gestational diabetes mellitus association to pregnancy outcomes: A national register-based cohort study

INTRODUCTION

It is well known that both women with polycystic ovary syndrome (PCOS) and women with gestational diabetes mellitus (GDM) have increased risks of adverse pregnancy outcomes, but little is known whether the combination of these two conditions exacerbates the risks. We explored risk estimates for adverse pregnancy outcomes in women with either PCOS or GDM and the combination of both PCOS and GDM.

MATERIAL AND METHODS

Nationwide register-based historical cohort study in Sweden including women who gave birth to singleton infants during 1997-2015 (N = 281 806). The risks of adverse pregnancy outcomes were estimated for women exposed for PCOS-only (n = 40 272), GDM-only (n = 2236), both PCOS and GDM (n = 1036) using multivariable logistic regression analyses. Risks were expressed as odds ratios with 95% confidence intervals (CIs) and adjusted for maternal characteristics, including maternal BMI. Women with neither PCOS nor GDM served as control group. Maternal outcomes were gestational hypertension, preeclampsia, postpartum hemorrhage, and obstetric anal sphincter injury. Neonatal outcomes were preterm birth, stillbirth, shoulder dystocia, born small or large for gestational age, macrosomia, low Apgar score, infant birth trauma, cerebral impact of the infant, neonatal hypoglycemia, meconium aspiration syndrome and respiratory distress.

RESULTS

Based on non-significant PCOS by GDM interaction analyses, we found no evidence that having PCOS adds any extra risk beyond that of having GDM for maternal and neonatal outcomes. For example, the adjusted odds ratio for preeclampsia in women with PCOS-only were 1.18 (95% CI 1.11-1.26), for GDM-only 1.77 (95% CI 1.45-2.15), and for women with PCOS and GDM 1.86 (95% CI 1.46-2.36). Corresponding adjusted odds ratio for preterm birth in women with PCOS-only were 1.34 (95% CI 1.28-1.41), GDM-only 1.64 (95% CI 1.39-1.93), and for women with PCOS and GDM 2.08 (95% CI 1.67-2.58). Women with PCOS had an increased risk of stillbirth compared with the control group (aOR 1.52, 95% CI 1.29-1.80), whereas no increased risk was noted in women with GDM (aOR 0.58, 95% CI 0.24-1.39).

CONCLUSIONS

The combination of PCOS and GDM adds no extra risk beyond that of having GDM alone, for a number of maternal and neonatal outcomes. Nevertheless, PCOS is still an unrecognized risk factor in pregnancy, exemplified by the increased risk of stillbirth.

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.

Single-cell RNA transcriptomics in mice reveals embryonic origin of fibrosis due to maternal obesity

BACKGROUND

Over 40% of pregnant women in the USA are obese which negatively affects fetal development and offspring health. Maternal obesity (MO) leads to fibrotic infiltration in multiple tissues and organs of offspring during their adulthood although the origin and mechanisms are unclear.

METHODS

C57BL/6J female mice were fed a control and high-fat diet to mimic MO condition. Embryonic somatic tissues were obtained at E9.5, E11.5, and E13.5 (equivalent to 6 weeks of human pregnancy) from control (CON) and MO mice for single-cell RNA-sequencing (scRNA-seq). To explore the role of AMP-activated protein kinase (AMPK), AMPK was activated by metformin and A769662, and knocked out in embryonic mesenchymal cells (EMC) using AMPKα1 floxed mice.

FINDINGS

Using unsupervised clustering, we identified three major cell populations with fibrogenic capacity. Compared to CON, the population of fibrogenic cells increased dramatically (by ∼125%) due to MO, supporting an embryonic origin of fibrosis in the offspring. MO induced inflammatory response and elevated expression of transforming growth factor β (TGFβ) signalling and fibrogenic genes in embryos. MO inhibited AMPK and its activation by metformin and A769662 inhibited TGFβ signalling and fibrogenesis.

INTERPRETATION

MO profoundly enhances embryonic fibrogenesis, explaining the origin of fibrosis in the offspring of mothers living with obesity. Our data underscore the importance of early intervention, before 5-6 weeks of pregnancy, in improving embryonic development, and AMPK is an amiable target for suppressing excessive fibrogenesis in MO embryos to assist increasing populations of obese mothers having healthy children.

FUNDING

This work was funded by National Institutes of Health Grant R01HD067449.

Impact of metformin on neocortical development during pregnancy: Involvement of ERK and p35/CDK5 pathways

Metformin, the most commonly prescribed drug for the treatment of diabetes, is increasingly used during pregnancy to address various disorders such as diabetes, obesity, preeclampsia, and metabolic diseases. However, its impact on neocortex development remains unclear. Here, we investigated the direct effects of metformin on neocortex development, focusing on ERK and p35/CDK5 regulation. Using a pregnant rat model, we found that metformin treatment during pregnancy induces small for gestational age (SGA) and reduces relative cortical thickness in embryos and neonates. Additionally, we discovered that metformin inhibits neural progenitor cell proliferation in the sub-ventricular zone (SVZ)/ventricular zone (VZ) of the developing neocortex, a process possibly mediated by ERK inactivation. Furthermore, metformin induces neuronal apoptosis in the SVZ/VZ area of the developing neocortex. Moreover, metformin retards neuronal migration, cortical lamination, and differentiation, potentially through p35/CDK5 inhibition in the developing neocortex. Remarkably, compensating for p35 through in utero electroporation partially rescues metformin-impaired neuronal migration and development. In summary, our study reveals that metformin disrupts neocortex development by inhibiting neuronal progenitor proliferation, neuronal migration, cortical layering, and cortical neuron maturation, likely via ERK and p35/CDK5 inhibition. Consequently, our findings advocate for caution in metformin usage during pregnancy, given its potential adverse effects on fetal brain development.

Gestational Weight Gain, Pregnancy Related Complications and the Short-Term Risks for the Offspring

BACKGROUND AND OBJECTIVES

Maternal obesity influences pregnancy course in several different manners, and imbalanced nutrition during pregnancy may lead to various adverse pregnancy outcomes. Additionally, nutritional status during pregnancy may have implications for the health of the offspring and may possibly influence early motor development in children. The aim of this study was to assess the impact of excessive gestational weight gain (EGWG) on pregnancy outcomes and infant's motor development within the first twelve months of life.

MATERIALS AND METHODS

The study included 200 participants divided in two groups based on their gestational weight gain. Maternal, perinatal, and neonatal factors were analyzed, and early motor development was assessed using the Alberta infant motor scale (AIMS).

RESULTS

EGWG was significantly associated with: pre-pregnancy BMI (p < 0.001), family history for cardiovascular diseases (p = 0.013) and diabetes mellitus (p = 0.045), hypertensive disorder of pregnancy (p = 0.003), gestational diabetes mellitus (p < 0.001), gestational anemia (p = 0.001), vitamin D deficiency (p = 0.001), metformin use (p = 0.045), pre-labor premature rupture of membranes (p = 0.031), amniotic fluid index (p = 0.047), and APGAR score in the first five min of life (p = 0.007). Scored by AIMS, EGWG was significantly associated with parameters of early motor development at the age of three AIMS total (p < 0.001), six AIMS total (p < 0.001), nine AIMS total (p < 0.001), and twelve AIMS total (p < 0.001) months of infant's life.

CONCLUSIONS

The link between EGWG and adverse neurodevelopmental outcomes in offspring is a complex and multifaceted issue. Our results imply significant alterations in early motor development in the group of infants born from mothers who gained weight excessively during pregnancy. Further studies are needed to unravel the intricacies of this relationship and inform strategies for preventive interventions and supportive care during pregnancy and infancy.

Metformin: The Winding Path from Understanding Its Molecular Mechanisms to Proving Therapeutic Benefits in Neurodegenerative Disorders

Metformin, a widely prescribed medication for type 2 diabetes, has garnered increasing attention for its potential neuroprotective properties due to the growing demand for treatments for Alzheimer's, Parkinson's, and motor neuron diseases. This review synthesizes experimental and clinical studies on metformin's mechanisms of action and potential therapeutic benefits for neurodegenerative disorders. A comprehensive search of electronic databases, including PubMed, MEDLINE, Embase, and Cochrane library, focused on key phrases such as "metformin", "neuroprotection", and "neurodegenerative diseases", with data up to September 2023. Recent research on metformin's glucoregulatory mechanisms reveals new molecular targets, including the activation of the LKB1-AMPK signaling pathway, which is crucial for chronic administration of metformin. The pleiotropic impact may involve other stress kinases that are acutely activated. The precise role of respiratory chain complexes (I and IV), of the mitochondrial targets, or of the lysosomes in metformin effects remains to be established by further research. Research on extrahepatic targets like the gut and microbiota, as well as its antioxidant and immunomodulatory properties, is crucial for understanding neurodegenerative disorders. Experimental data on animal models shows promising results, but clinical studies are inconclusive. Understanding the molecular targets and mechanisms of its effects could help design clinical trials to explore and, hopefully, prove its therapeutic effects in neurodegenerative conditions.

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.

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.

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.

Gestational diabetes mellitus and size at birth modify early adiposity accretion. Evidence from the OBESO cohort

AIM

To evaluate the association between maternal obesity, gestational diabetes (GDM), and birth size with infant fat-mass (FM) accretion from 1 to 6 months (M).

METHODS

Healthy pregnant women and their term babies from the OBESO cohort were studied (1 M-3 M, n = 122; 1 M-6 M, n = 90). Registered maternal data was: pregestational body-mass-index (preBMI), GDM (2hOGTT), medications, gestational weight gain. Macrosomia (>4000 g), large/small for gestational age (LGA/SGA)(weight/age > 90° and < 90°, respectively-WHO) were recorded at birth. Infant FM (air-displacement plethysmography) was measured (1 M, 3 M, 6 M) and FM accretion computed (ΔkgFM from 1 M-3 M and 1 M-6 M). Exclusive breastfeeding (EBF) was assessed. Adjusted-multiple linear regression models were performed.

RESULTS

PreBMI was 27.4 ± 5.2 kg/m2. GDM was present in9%(n = 11) of women; 12.3%(n = 15) of them received metformin/insulin. One newborn was LGA; 20.7%(n = 25) were SGA. From 1 M-3 M, SGA was a predictor of higher FM accretion (B:0.28, 95%CI:0.14-0.43); GDM was not associated. From 1 M-6 M, higher FM accretion was observed in SGA newborns (B:0.43, 95%CI:0.19-0.67) and GDM infants (B:0.48, 95%CI:0.06-0.89). In all models (R2 ≥ 0.48, p < 0.001), infant weight and being female were positively associated, while maternal obesity, metformin/insulin, and EBF were not.

CONCLUSIONS

GDM appears to program early higher adiposity accretion, independently of excessive fetal growth. SGA was associated with higher FM accretion in early infancy.

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.

Lights and shadows on the use of metformin in pregnancy: from the preconception phase to breastfeeding and beyond

During pregnancy, the complex hormonal changes lead to a progressive decrease of insulin sensitivity that can drive the onset of gestational diabetes (GDM) or worsen an already-known condition of insulin resistance like type 2 diabetes, polycystic ovarian syndrome (PCOS), and obesity, with complications for the mother and the fetus. Metformin during pregnancy is proving to be safe in a growing number of studies, although it freely crosses the placenta, leading to a fetal level similar to maternal concentration. The aim of this literature review is to analyze the main available evidence on the use of metformin during, throughout, and beyond pregnancy, including fertilization, lactation, and medium-term effects on offspring. Analyzed studies support the safety and efficacy of metformin during pregnancy. In pregnant women with GDM and type 2 diabetes, metformin improves obstetric and perinatal outcomes. There is no evidence that it prevents GDM in women with pregestational insulin resistance or improves lipid profile and risk of GDM in pregnant women with PCOS or obesity. Metformin could have a role in reducing the risk of preeclampsia in pregnant women with severe obesity, the risk of late miscarriages and preterm delivery in women with PCOS, and the risk of ovarian hyperstimulation syndrome, increasing the clinical pregnancy rate in women with PCOS undergoing in vitro fertilization (IVF/FIVET). Offspring of mothers with GDM exposed to metformin have no significant differences in body composition compared with insulin treatment, while it appears to be protective for metabolic and cardiovascular risk.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Metformin: Sex/Gender Differences in Its Uses and Effects—Narrative Review

Metformin (MTF) occupies a major and fundamental position in the therapeutic management of type 2 diabetes mellitus (T2DM). Gender differences in some effects and actions of MTF have been reported. Women are usually prescribed lower MTF doses compared to men and report more gastrointestinal side effects. The incidence of cardiovascular events in women on MTF has been found to be lower to that of men on MTF. Despite some promising results with MTF regarding pregnancy rates in women with PCOS, the management of gestational diabetes, cancer prevention or adjunctive cancer treatment and COVID-19, most robust meta-analyses have yet to confirm such beneficial effects.