First-trimester exposure to metformin and risk of birth defects: a systematic review and meta-analysis

Metformin beyond type 2 diabetes: Emerging and potential new indications

Metformin is best known as a foundational therapy for type 2 diabetes but is also used in other contexts in clinical medicine with a number of emerging and potential indications. Many of its beneficial effects may be mediated by modest effects on weight loss and insulin sensitivity, but it has multiple other known mechanisms of action. Current clinical uses beyond type 2 diabetes include: polycystic ovarian syndrome; diabetes in pregnancy/gestational diabetes; prevention of type 2 diabetes in prediabetes; and adjunct therapy in type 1 diabetes. As metformin has been in clinical use for almost 70 years, much of the underpinning evidence for its use in these conditions is, by definition, based on trials conducted before the advent of contemporary evidence-based medicine. As a result, some of the above-established uses are 'off-label' in many regulatory territories and their use varies accordingly in different countries. Going forward, several current 'repurposing' investigational uses of metformin are also being investigated: prevention of cancer (including in Li Fraumeni syndrome), renal protection, Alzheimer's disease, metabolic dysfunction-associated steatotic liver disease and promotion of healthy ageing. Despite the longevity of metformin and its important current roles beyond type 2 diabetes in clinical medicine, it has further potential and much research is ongoing.

Epidemiology and management of gestational diabetes

Gestational diabetes is defined as hyperglycaemia first detected during pregnancy at glucose concentrations that are less than those of overt diabetes. Around 14% of pregnancies globally are affected by gestational diabetes; its prevalence varies with differences in risk factors and approaches to screening and diagnosis; and it is increasing in parallel with obesity and type 2 diabetes. Gestational diabetes direct costs are US$1·6 billion in the USA alone, largely due to complications including hypertensive disorders, preterm delivery, and neonatal metabolic and respiratory consequences. Between 30% and 70% of gestational diabetes is diagnosed in early pregnancy (ie, early gestational diabetes defined by hyperglycaemia before 20 weeks of gestation). Early gestational diabetes is associated with worse pregnancy outcomes compared with women diagnosed with late gestational diabetes (hyperglycaemia from 24 weeks to 28 weeks of gestation). Randomised controlled trials show benefits of treating gestational diabetes from 24 weeks to 28 weeks of gestation. The WHO 2013 recommendations for diagnosing gestational diabetes (one-step 75 gm 2-h oral glucose tolerance test at 24-28 weeks of gestation) are largely based on the Hyperglycemia and Adverse Pregnancy Outcomes Study, which confirmed the linear association between pregnancy complications and late-pregnancy maternal glycaemia: a phenomenon that has now also been shown in early pregnancy. Recently, the Treatment of Booking Gestational Diabetes Mellitus (TOBOGM) trial showed benefit in diagnosis and treatment of early gestational diabetes for women with risk factors. Given the diabesity epidemic, evidence for gestational diabetes heterogeneity by timing and subtype, and advances in technology, a life course precision medicine approach is urgently needed, using evidence-based prevention, diagnostic, and treatment strategies.

Childbirth experiences in women with polycystic ovary syndrome: A cohort study

INTRODUCTION

Women with polycystic ovary syndrome (PCOS) have more pregnancy complications like gestational diabetes, hypertension, and preterm labor than other women. Metformin has been used in an attempt to improve pregnancy outcomes. Our study aims to explore childbirth experiences in women with PCOS compared with a reference population. It also explores the potential influence of metformin, obesity, pregnancy complications, and the duration and mode of birth on childbirth experiences.

MATERIAL AND METHODS

This study is a cohort study combining data from two randomized trials conducted in Norway, Sweden and Iceland. The PregMet2 study (ClinicalTrials.gov, NCT01587378) investigated the use of metformin vs. placebo in pregnant women with PCOS. The Labour Progression Study (ClinicalTrials.gov, NCT02221427) compared the WHO partograph to Zhang's guidelines for progression of labor and were used as the reference population. A total of 365 women with PCOS and 3604 reference women were included. Both studies used the Childbirth Experience Questionnaire (CEQ). Main outcome measures were total CEQ score and four domain scores. The CEQ scores were compared using Mann-Whitney U test for women in Robson group 1 with PCOS (n = 131) and reference women (n = 3604). CEQ scores were also compared between metformin-treated (n = 180) and placebo-treated (n = 185) women with PCOS, and for different subgroups of women with PCOS.

RESULTS

There was no difference in total CEQ score between women with PCOS and reference women-Wilcoxon-Mann-Whitney (WMW)-odds 0.96 (95% confidence interval [CI] 0.78-1.17). We detected no difference in CEQ scores between the metformin- and placebo-treated women with PCOS (WMW-odds 1.13, 95% CI 0.89-1.43). Complications in pregnancy did not affect CEQ (WMW-odds 1, 95% CI 0.76-1.31). Higher body mass index (WMW-odds 0.75, 95% CI 0.58-0.96), longer duration of labor (WMW-odds 0.69, 95% CI 0.49-0.96), and cesarean section (WMW-odds 0.29, 95% CI 0.2-0.42) were associated with lower CEQ scores in women with PCOS.

CONCLUSIONS

Women with PCOS experience childbirth similarly to the reference women. Metformin did not influence childbirth experience in women with PCOS, neither did pregnancy complications. Obesity, long duration of labor or cesarean section had a negative impact on childbirth experience.

Effect of Consultation Number on the Assessment and Treatment of Polycystic Ovary Syndrome

Background

The basic medical education stage is not enough to support physicians to fully diagnose and evaluate polycystic ovary syndrome (PCOS). The study aims to discover the difference in treatment choice between participants with different annual consultation number of PCOS, to promote lifelong learning, and drive balanced development within healthcare.

Methods

This is a multicenter cross-sectional survey. Participants' basic information, knowledge of PCOS and treatment options were collected online. According to the annual consultation number of patients with PCOS, physicians were divided into three groups: 0-50 people/yr, 50-200 people/yr, and >200 people/yr, and the results were derived from χ2 test, Fisher exact test, and multivariate logistic regression analysis.

Results

The study analyzed 1689 questionnaires, and 1206 physicians (71.4%) received less than 50 women per year, 388 physicians (30.0%) with an annual number of 50-200 women, and 95 physicians (5.6%) with patient turnover for more than 200 people. Reproductive endocrinologists generally have higher access to the clinic. As the number of visits increases, more and more physicians would perceive patients as more likely to have abnormal blood glucose and heavy weight. Physicians with large numbers of consultations are more likely to use Asian or Chinese standards to assess obesity. The multivariate analysis involved variables such as age, hospital level, specialty, and patient turnover annually, and more young doctors actively assessed lipid profile (odds ratio (OR) 1.56, 95% confidence interval (CI) (1.16, 2.16)), and primary hospitals (OR 0.65 CI (0.44, 0.89)) chose OGTT for blood glucose assessment less than tertiary hospitals. Physicians in secondary hospitals are more aggressive in evaluating androgens.

Conclusion

Our survey found differences in endocrine assessment, metabolic screening, and treatment in PCOS women in terms of the number of obstetrician-gynecologists who received different patient consultation numbers. The importance of continuing education for physicians is emphasized, to promote lifelong learning.

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.

Anthropometrics of neonates born to mothers with PCOS with metformin or placebo exposure in utero

INTRODUCTION

Fetal growth may be affected by both maternal polycystic ovary syndrome (PCOS) and metformin therapy. Here, we explore the effect of intrauterine metformin exposure on birth anthropometrics of infants born to women with PCOS. We also investigated whether the effect of metformin on birth anthropometrics is modified by maternal pre-pregnancy body mass index, PCOS hyperandrogenic phenotype, serum androgen levels, preconception use of metformin and offspring sex. Additionally, we assessed newborn anthropometrics in relation to a national reference population.

MATERIAL AND METHODS

Individual data from three randomized controlled triasl were pooled. The randomized controlled trials investigated the effects of metformin in pregnant women with PCOS. In all, 397 and 403 were randomized to the metformin and placebo groups, respectively. A Scandinavian growth reference was used to calculate sex and gestational age adjusted z-scores. Linear regression models were used to estimate the effect of metformin on offspring z-scores of head circumference, birth length, birthweight, placental weight, body mass index, ponderal index and birthweight:placental weight ratio. S-testosterone, s-androstenedione, and s-sex-hormone binding globulin from four timepoints in pregnancy were analyzed.

RESULTS

Compared with the PCOS-placebo group, newborns in the PCOS-metformin group had larger head circumference (head circumference z-score: mean difference = 0.25, 95% CI = 0.11- 0.40). This effect of metformin on head circumference z-score was particularly observed among offspring of overweight/obese mothers and mothers with hyperandrogenic PCOS-phenotype. We observed no difference in other anthropometric measures between the metformin and placebo groups or any clear interaction between maternal androgen levels and metformin. Newborns in the PCOS-placebo group were shorter than in the reference population (birth length z-score: mean = -0.04, 95% CI = -0.05 to -0.03), but head circumference and birthweight were similar.

CONCLUSIONS

Larger head circumference was observed at birth in metformin-exposed offspring of mothers with PCOS. PCOS-offspring were also shorter, with a similar birthweight to the reference population, indirectly indicating higher weight-to-height ratio at birth.

Metformin adverse event profile: a pharmacovigilance study based on the FDA Adverse Event Reporting System (FAERS) from 2004 to 2022

BACKGROUND

Metformin has the potential for treating numerous diseases, but there are still many unrecognized and unreported adverse events (AEs).

METHODS

We selected data from the United States FDA Adverse Event Reporting System (FAERS) database from the first quarter (Q1) of 2004 to the fourth quarter (Q4) of 2022 for disproportionality analysis to assess the association between metformin and related adverse events.

RESULTS

In this study 10,500,295 case reports were collected from the FAERS database, of which 56,674 adverse events related to metformin were reported. A total of 643 preferred terms (PTs) and 27 system organ classes (SOCs) that were significant disproportionality conforming to the four algorithms simultaneously were included. The SOCs included metabolic and nutritional disorders (p = 0.00E + 00), gastrointestinal disorders (p = 0.00E + 00) and others. PT levels were screened for adverse drug reaction (ADR) signals such as acute pancreatitis (p = 0.00E + 00), melas syndrome, pemphigoid (p = 0.00E + 00), skin eruption (p = 0.00E + 00) and drug exposure during pregnancy (p = 0.00E + 00).

CONCLUSION

Most of our results were consistent with the specification, but some new signals of adverse reactions such as acute pancreatitis were not included. Therefore, further studies are needed to validate unlabeled adverse reactions and provide important support for clinical monitoring and risk identification of metformin.

Insulin Resistance, Obesity, and Lipotoxicity

Lipotoxicity, originally used to describe the destructive effects of excess fat accumulation on glucose metabolism, causes functional impairments in several metabolic pathways, both in adipose tissue and peripheral organs, like liver, heart, pancreas, and muscle. Ectopic lipid accumulation in the kidneys, liver, and heart has important clinical counterparts like diabetic nephropathy in type 2 diabetes mellitus, obesity-related glomerulopathy, nonalcoholic fatty liver disease, and cardiomyopathy. Insulin resistance due to lipotoxicity indirectly lead to reproductive system disorders, like polycystic ovary syndrome. Lipotoxicity has roles in insulin resistance and pancreatic beta-cell dysfunction. Increased circulating levels of lipids and the metabolic alterations in fatty acid utilization and intracellular signaling have been related to insulin resistance in muscle and liver. Different pathways, like novel protein kinase c pathways and the JNK-1 pathway, are involved as the mechanisms of how lipotoxicity leads to insulin resistance in nonadipose tissue organs, such as liver and muscle. Mitochondrial dysfunction plays a role in the pathogenesis of insulin resistance. Endoplasmic reticulum stress, through mainly increased oxidative stress, also plays an important role in the etiology of insulin resistance, especially seen in non-alcoholic fatty liver disease. Visceral adiposity and insulin resistance both increase the cardiometabolic risk, and lipotoxicity seems to play a crucial role in the pathophysiology of these associations.

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.

Metformin in Gestational Diabetes Mellitus: To Use or Not to Use, That Is the Question

In recent years, there has been a dramatic increase in the number of pregnancies complicated by gestational diabetes mellitus (GDM). GDM occurs when maternal insulin resistance develops and/or progresses during gestation, and it is not compensated by a rise in maternal insulin secretion. If not properly managed, this condition can cause serious short-term and long-term problems for both mother and child. Lifestyle changes are the first line of treatment for GDM, but if ineffective, insulin injections are the recommended pharmacological treatment choice. Some guidance authorities and scientific societies have proposed the use of metformin as an alternative pharmacological option for treating GDM, but there is not yet a unanimous consensus on this. Although the use of metformin appears to be safe for the mother, concerns remain about its long-term metabolic effects on the child that is exposed in utero to the drug, given that metformin, contrary to insulin, crosses the placenta. This review article describes the existing lines of evidence about the use of metformin in pregnancies complicated by GDM, in order to clarify its potential benefits and limits, and to help clinicians make decisions about who could benefit most from this drug treatment.

Polycystic Ovary Syndrome: Challenges and Possible Solutions

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. This syndrome not only impairs female fertility but also increases the risk of obesity, diabetes, dyslipidemia, cardiovascular diseases, psychological diseases, and other health problems. Additionality, because of the high clinical heterogeneity, the current pathogenesis of PCOS is still unclear. There is still a large gap in precise diagnosis and individualized treatment. We summarize the present findings concerning the genetics, epigenetics, gut microbiota, corticolimbic brain responses, and metabolomics of the PCOS pathogenesis mechanism, highlight the remaining challenges in PCOS phenotyping and potential treatment approaches, and explain the vicious circle of intergenerational transmission of PCOS, which might provide more thoughts for better PCOS management in the future.

Major malformations risk following early pregnancy exposure to metformin: a systematic review and meta-analysis

Metformin is considered as first-line treatment for type 2 diabetes and an effective treatment for polycystic ovary syndrome (PCOS). However, evidence regarding its safety in pregnancy is limited. We conducted a systematic review and meta-analysis of major congenital malformations (MCMs) risk after first-trimester exposure to metformin in women with PCOS and pregestational diabetes mellitus (PGDM). Randomized controlled trials (RCTs) and observational cohort studies with a control group investigating risk of MCM after first-trimester pregnancy exposure to metformin were searched until December 2021. ORs and 95% CIs were calculated separately according to indications and study type using Mantel-Haenszel method; outcome data were combined using random-effects model. Eleven studies (two RCTs; nine observational cohorts) met the inclusion criteria: four included pregnant women with PCOS, four included those with PGDM and three evaluated both indications separately and were considered in both indication groups. In PCOS group, there were two RCTs (57 exposed, 52 control infants) and five observational studies (472 exposed, 1892 control infants); point estimates for MCM rates in RCTs and observational studies were OR 0.93 (95% CI 0.09 to 9.21) (I2=0%; Q test=0.31; p value=0.58) and OR 1.35 (95% CI 0.37 to 4.90) (I2=65%; Q test=9.43; p value=0.05), respectively. In PGDM group, all seven studies were observational (1122 exposed, 1851 control infants); the point estimate for MCM rates was OR 1.05 (95% CI 0.50 to 2.18) (I2=59%; Q test=16.34; p value=0.01). Metformin use in first-trimester pregnancy in women with PCOS or PGDM do not meaningfully increase the MCM risk overall. However, further studies are needed to characterize residual safety concerns.

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

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

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

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT02947503.

The use of metformin in women with polycystic ovary syndrome: an updated review

PURPOSES

Polycystic ovary syndrome (PCOS) is a major cause of female infertility, being present in up to 20% of women of childbearing age. Insulin resistance (IR) plays an important role in the pathophysiology of PCOS; therefore, its treatment may benefit women with the syndrome. The main drug used for IR management is metformin (MT). We aim to review the literature on the use of metformin in women with PCOS.

METHODS

Using the terms "metformin" and "polycystic ovary syndrome," we conducted a search the PubMed, EMBASE, and Google Scholar databases. The research was restricted to articles published in English. Initially, only published meta-analyses were included, in the absence of meta-analyzes, RCT and well-designed prospective studies were used.

RESULTS

Metformin increases success rates and decreases complication rates when used as an adjunctive medication for ovulation induction during low complexity assisted reproduction treatments and during ovarian stimulation for in vitro fertilization in women with PCOS. Evidence about the effect of metformin on fetal and obstetric complication rates is conflicting. Metformin is associated with high incidence of gastrointestinal symptoms; however, serious adverse effects are rare and there is no evidence of teratogenicity.

CONCLUSION

For women with PCOS, metformin is a good adjunctive medication for ovulation induction/stimulation for high and low complexity assisted reproduction therapies. The adverse effects are mostly mild, and there is no risk of teratogenicity, but the risk of long-term complications for the offspring is not yet defined. High heterogeneity of the studies limits extrapolation of findings, and further research is needed to determine which women will benefit most from the medication.

Metformin for pregnancy and beyond: the pros and cons

CONTEXT AND AIM

Metformin has been used in pregnancy since the 1970s. It is cheap, widely available and is acceptable to women. Despite its increasing use, controversy remains surrounding its benefits and risks. Metformin effectively reduces hyperglycaemia for the mother during pregnancy and it reduces rates of macrosomia and neonatal hypoglycaemia. However, concern exists surrounding an increase in the rate of SGA births and obesity in childhood. We aim to review the evidence and expert opinion behind metformin in pregnancy through to the post-partum period.

METHODS

We performed a literature review of relevant studies from online databases using a combination of keywords. We also searched the references of retrieved articles for pertinent studies.

RESULTS

There is strong evidence that metformin is safe in early pregnancy with no risk of congenital malformations. If used throughout pregnancy, it is likely to lead to reduced maternal weight gain and reduced insulin dose in women with type 2 diabetes. In infants, metformin reduces hypoglycaemia and macrosomia but may increase the rate of infants born SGA. There is some evidence of an increased risk of obesity and altered fat distribution in offspring. Metformin appears well tolerated in pregnancy and is more acceptable to women than insulin therapy.

CONCLUSION

Due to increasing rates of maternal obesity, GDM and type 2 diabetes, metformin use in pregnancy is increasing. Overall, it appears safe and effective but further research is needed to examine mechanisms linking metformin to obesity reported during childhood in some follow-up studies.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Association of serum fetuin-B with insulin resistance and pre-diabetes in young Chinese women: evidence from a cross-sectional study and effect of liraglutide

Background and Aims

Fetuin-B has been reported to be involved in glucose and lipid metabolism and associated with the occurrence of diabetes. The main purpose of this study is to explore the changes of circulating fetuin-B in young women with pre-diabetes and to analyze the relationship between fetuin-B and the occurrence and development of IR.

Methods

A total of 304 women were enrolled in this study and subjected to both OGTT and EHC. A subgroup of 26 overweight/obese womenwas treated with Lira for 24 weeks. serum fetuin-B concentrations were measured by ELISA.

Results

In IGT and IR-NG groups, serum fetuin-B levels were higher than those in the NGT group. The serum fetuin-B levels in the IGT group were higher than those in the IR-NG group. serum fetuin-B was positively correlated with BMI, WHR, 2h-BG, FIns, HbA1c, and HOMA2-IR, but negatively correlated with the M-value in all study populations. Multiple stepwise regression analysis showed that the M-value was independently and inversely associated with serum fetuin-B. Logistic regression analysis showed that serum fetuin-B was independently associated with IGT and significantly increased the risk of IGT. During the OGTT, serum fetuin-B increased significantly in the NGT group, but there were no significant changes in other groups. During the EHC, serum fetuin-B increased in the IGT group, but there was no change in other groups. After Lira intervention, serum fetuin-B decreased significantly in IGT women.

Conclusions

serum fetuin-B levels are elevated in young women with IR or IGT and may be associated with IR.

Effects of metformin treatment on pregnancy outcomes in patients with polycystic ovary syndrome

INTRODUCTION

This review covers the current evidence regarding the use of metformin as a therapeutic intervention for optimizing pregnancy outcomes in women with polycystic ovary syndrome (PCOS).

AREAS COVERED

After searching Medline, Embase and CINAHL, all important large clinical trials and observational studies plus systematic reviews, meta-analyses and Cochrane reviews have been summarized here. The results have been compared to culminate in a thorough review and discussion on the use of metformin in relation to reproductive outcomes for women with PCOS. The role of metformin in PCOS is explored both in terms of achieving conception and during pregnancy. The existing evidence around metformin use is summarized both during the preconceptual period and during pregnancy, in relation to reproductive outcomes.

EXPERT OPINION

Metformin is a widely used medication, often prescribed to improve reproductive outcomes for women with PCOS. However, the evidence remains equivocal regarding its efficacy both in optimizing fertility and pregnancy outcomes. More research is required with special emphasis on metformin use within different populations, including ethnic groups and women with varying BMI ranges.

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

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

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Metformin: Up to Date

BACKGROUND

Metformin is an oral hypoglycemic agent extensively used as first-line therapy for type 2 diabetes. It improves hyperglycemia by suppressing hepatic glucose production and increasing glucose uptake in muscles. Metformin improves insulin sensitivity and shows a beneficial effect on weight control. Besides its metabolic positive effects, Metformin has direct effects on inflammation and can have immunomodulatory and antineoplastic properties.

AIM

The aim of this narrative review was to summarize the up-to-date evidence from the current literature about the metabolic and non-metabolic effects of Metformin.

METHODS

We reviewed the current literature dealing with different effects and properties of Metformin and current recommendations about the use of this drug. We identified keywords and MeSH terms in Pubmed and the terms Metformin and type 2 diabetes, type 1 diabetes, pregnancy, heart failure, PCOS, etc, were searched, selecting only significant original articles and review in English, in particular of the last five years.

CONCLUSION

Even if many new effective hypoglycemic agents have been launched in the market in the last few years, Metformin would always keep a place in the treatment of type 2 diabetes and its comorbidities because of its multiple positive effects and low cost.

ADIPS 2020 guideline for pre-existing diabetes and pregnancy

This is the full version of the Australasian Diabetes in Pregnancy Society (ADIPS) 2020 guideline for pre-existing diabetes and pregnancy. The guideline encompasses the management of women with pre-existing type 1 diabetes and type 2 diabetes in relation to pregnancy, including preconception, antepartum, intrapartum and postpartum care. The management of women with monogenic diabetes or cystic fibrosis-related diabetes in relation to pregnancy is also discussed.

Fetal safety of medications used in treating infertility

INTRODUCTION

The medications used in assisted reproduction are given before and during early pregnancy, and hence, they may potentially result in adverse fetal effects. In this review we present an updated account of their fetal safety and discuss methodological challenges in interpretation of existing data.

AREAS COVERED

The fetal safety/risks of clomiphene citrate, aromatase inhibitors, metformin, gonadotropins and progestins are discussed. We searched PubMed, EMBASE, Cochrane, Google, and Google Scholar from inception to 30 April 2020 for publications pertinent to our topic.

EXPERT OPINION

There are several major challenges in studying fetal safety of medications used in assisted reproduction. The fact is that the rates of congenital malformations among infertile women giving birth spontaneously is higher than the rates among healthy women conceiving spontaneously. In most clinical studies of assisted reproduction, the primary endpoint is the success in inducing pregnancy, neglecting to report pregnancy outcome and adverse neonatal event. As an example for this reality, it has been estimated that between 1977 and 2005 around 10 million pregnancies were treated with dydrogesterone (DYD), yet till 2019 only very few studies, with a total sample size of less than 600 were reported with regards to fetal safety.

Prevention of preeclampsia

Preeclampsia is an obstetric disorder that affects 3-8% of pregnant women and remains a leading cause of short- and long-term neonatal and maternal morbidity and mortality. Professional societies recommend the use of low dose aspirin to prevent preeclampsia in high-risk women. However, interest in prevention of this disease and better understanding of its pathophysiology have led to growing research on other agents. This review focuses on the main therapeutic agents evaluated or in use for preeclampsia prevention.

Pregestational diabetes in pregnancy: Complications, management, surveillance, and mechanisms of disease-A review

Diabetes is an increasingly common diagnosis among pregnant women. Pregestational diabetes is associated with an increase in many adverse pregnancy outcomes, which impact both on the woman and her fetus. The models of pregnancy care for women with diabetes are based largely on observational data or consensus opinion. Strategies for aneuploidy screening and monitoring for fetal well-being should be modified in women with diabetes. There is an increasing understanding of the mechanisms by which congenital anomalies and disorders of fetal growth occur, involving epigenetic modifications, changes in gene expression in critical developmental pathways, and oxidative stress. This knowledge may lead to pathways for improved care for these high-risk pregnancies.

Metformin and Pregnancy Outcomes: Evidence Gaps and Unanswered Questions

BACKGROUND

Metformin is sometimes used as an alternative to insulin in gestational diabetes mellitus (GDM). It is also used to achieve ovulation in polycystic ovary syndrome (PCOS). Pre-natal exposure to metformin results from its continuation after a successful ovulation in women with PCOS, its maintenance in women with pre-gestational diabetes or the installation of metformin in GDM. Little is known about the potential consequences of metformin exposure on pregnancy outcomes and offspring development. The aim of this review is to summarize the metformin effects on pregnancy outcomes and offspring development. Gaps in the available evidence and unanswered questions are also discussed.

METHODS

A comprehensive literature search was carried out to identify eligible studies from MEDLINE/PubMed, EMBASE and SCIELO databases through 1995 first semester.

RESULTS

Several factors limit the effect of metformin on embryos. In contrast, placental transport of metformin is effective allowing for a higher fetal exposure; the impact of this finding remains unclear. It seems that the interruption of metformin after a pregnancy diagnosis in women with PCOS is not associated with a higher miscarriage risk and it continuation does not seem to impair the maternal metabolic prognosis or prevent emerging GDM.

CONCLUSIONS

It seems to have no sense to prolong the use of metformin after a pregnancy diagnosis in women with PCOS. Patients with GDM may be treated with metformin under on judicious basis, and a careful attachment to clinical guidelines and regulations is recommended. The long-term effects of pre-natal exposure to metformin on the offspring remain uncertain.

Polycystic Ovary Syndrome: Impact of Lipotoxicity on Metabolic and Reproductive Health

Importance

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. Women with PCOS are at increased risk of developing several metabolic and reproductive abnormalities, including metabolic syndrome. Underlying the combined metabolic and reproductive dysfunction is lipotoxicity, defined as the ectopic deposition of lipid in nonadipose tissue where it induces oxidative stress linked with insulin resistance and inflammation.

Objective

To examine what metabolic components underlie insulin resistance in PCOS, how lipotoxicity through insulin resistance impairs metabolism and reproduction in these women, and why evidence-based, individualized management is essential for their care.

Evidence Acquisition

PubMed search was performed using relevant terms to identify journal articles related to the subject. Relevant textbook chapters were also used.

Results

Polycystic ovary syndrome by Rotterdam criteria represents a complex syndrome of heterogeneous expression with variable adverse metabolic and reproductive implications. Women with classic PCOS are often insulin resistant and at greatest risk of developing metabolic syndrome with preferential fat accumulation and weight gain. Moreover, PCOS women may also have an altered capacity to properly store fat, causing ectopic lipid accumulation in nonadipose tissue, including the ovaries, where it can perpetuate insulin resistance and inflammation and harm the oocyte.

Conclusions and Relevance

A personalized approach to managing PCOS is essential to improve the health of all PCOS women through cost-effective prevention and/or treatment, to minimize the risk of pregnancy complications in those individuals wishing to conceive, and to optimize the long-term health of PCOS women and their offspring.

Novel Interventions for the Prevention of Preeclampsia

PURPOSE OF REVIEW

To review the rationale and biological plausibility and discuss the current research on novel interventions for the prevention of preeclampsia.

RECENT FINDINGS

Preeclampsia affects up to 8% of pregnancies worldwide and remains a major cause of maternal and neonatal morbidity and mortality. Multiple medications have been investigated or repurposed as potential effective interventions for preeclampsia prevention. Aspirin is currently the only drug for which there is some evidence of benefit for preeclampsia prevention, and its use is recommended by professional societies for pregnancies at risk. Statins have shown promise for prevention of preeclampsia in animal models and human pilot studies, without any trend or concerns for safety signals or teratogenicity. The use of metformin has also gained popularity in experimental studies, but observations from randomized clinical trials were not consistent on its utility as a possible intervention for preeclampsia prevention. While initial studies evaluating esomeprazole were promising, randomized trials failed to show benefit. Contemporary research shows exciting new opportunities for prophylactic treatment for preeclampsia, to prevent this debilitating and life-threatening disease.

Pharmacological intervention for diabetes after pregnancy prevention in women with prior gestational diabetes: A scoping review

Women with previous gestational diabetes mellitus (GDM) are at increased risk of developing diabetes after pregnancy (DAP), especially 5-10 years postpartum. Two well-known diabetes prevention trials demonstrated a significant reduction in DAP incidence using metformin and troglitazone; however, since their publication, several novel classes of anti-hyperglycemic agents have emerged. This review aimed to conduct a systematic literature search for new evidence in support of pharmacotherapy in DAP prevention and to analyze the results based on special considerations for women of reproductive potential. The only studies whose primary outcome was DAP incidence were those examining metformin, the thiazolidinediones troglitazone and pioglitazone, and the dipeptidyl peptidase-4 inhibitor vildagliptin. Metformin was effective in DAP reduction and was well tolerated, but participants were on average 12 years beyond their GDM pregnancy. Troglitazone was also shown to prevent DAP, but was withdrawn from the market due to hepatotoxicity. There was no comparator arm in the pioglitazone study, which limits its interpretability. The vildagliptin study was underpowered. There are ongoing trials with glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, but none with diabetes incidence as a primary outcome. This review highlights the limited evidence base for pharmacological prevention of DAP.

Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation, and high levels of androgens and insulin (hyperinsulinaemia). Hyperinsulinaemia occurs secondary to insulin resistance and is associated with an increased biochemical risk profile for cardiovascular disease and an increased prevalence of diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating PCOS-related anovulation. This is an update of Morley 2017 and only includes studies on metformin.

OBJECTIVES

To evaluate the effectiveness and safety of metformin in combination with or in comparison to clomiphene citrate (CC), letrozole and laparoscopic ovarian drilling (LOD) in improving reproductive outcomes and associated gastrointestinal side effects for women with PCOS undergoing ovulation induction.

SEARCH METHODS

We searched the following databases from inception to December 2018: Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. We searched registers of ongoing trials and reference lists from relevant studies.

SELECTION CRITERIA

We included randomised controlled trials of metformin compared with placebo, no treatment, or in combination with or compared with CC, letrozole and LOD for women with PCOS subfertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility and bias. Primary outcomes were live birth rate and gastrointestinal adverse effects. Secondary outcomes included other pregnancy outcomes and ovulation. We combined data to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We assessed statistical heterogeneity using the I² statistic and reported quality of the evidence for primary outcomes and reproductive outcomes using GRADE methodology.

MAIN RESULTS

We included 41 studies (4552 women). Evidence quality ranged from very low to moderate based on GRADE assessment. Limitations were risk of bias (poor reporting of methodology and incomplete outcome data), imprecision and inconsistency. Metformin versus placebo or no treatment The evidence suggests that metformin may improve live birth rates compared with placebo (OR 1.59, 95% CI 1.00 to 2.51; I² = 0%; 4 studies, 435 women; low-quality evidence). For a live birth rate of 19% following placebo, the live birth rate following metformin would be between 19% and 37%. The metformin group probably experiences more gastrointestinal side effects (OR 4.00, 95% CI 2.63 to 6.09; I² = 39%; 7 studies, 713 women; moderate-quality evidence). With placebo, the risk of gastrointestinal side effects is 10% whereas with metformin this risk is between 22% and 40%. There are probably higher rates of clinical pregnancy (OR 1.98, 95% CI 1.47 to 2.65; I² = 30%; 11 studies, 1213 women; moderate-quality evidence). There may be higher rates of ovulation with metformin (OR 2.64, 95% CI 1.85 to 3.75; I² = 61%; 13 studies, 684 women; low-quality evidence). We are uncertain about the effect on miscarriage rates (OR 1.08, 95% CI 0.50 to 2.35; I² = 0%; 4 studies, 748 women; low-quality evidence). Metformin plus CC versus CC alone We are uncertain if metformin plus CC improves live birth rates compared to CC alone (OR 1.27, 95% CI 0.98 to 1.65; I² = 28%; 10 studies, 1219 women; low-quality evidence), but gastrointestinal side effects are probably more common with combined therapy (OR 4.26, 95% CI 2.83 to 6.40; I² = 8%; 6 studies, 852 women; moderate quality evidence). The live birth rate with CC alone is 24%, which may change to between 23% to 34% with combined therapy. With CC alone, the risk of gastrointestinal side effects is 9%, which increases to between 21% to 37% with combined therapy. The combined therapy group probably has higher rates of clinical pregnancy (OR 1.62, 95% CI 1.32 to 1.99; I² = 31%; 19 studies, 1790 women; moderate-quality evidence). The combined group may have higher rates of ovulation (OR 1.65, 95% CI 1.35 to 2.03; I² = 63%;21 studies, 1568 women; low-quality evidence). There was no clear evidence of an effect on miscarriage (OR 1.35, 95% CI 0.91 to 2.00; I² = 0%; 10 studies, 1206 women; low-quality evidence). Metformin versus CC When all studies were combined, findings for live birth were inconclusive and inconsistent (OR 0.71, 95% CI 0.49 to 1.01; I² = 86%; 5 studies, 741 women; very low-quality evidence). In subgroup analysis by obesity status, obese women had a lower birth rate in the metformin group (OR 0.30, 95% CI 0.17 to 0.52; 2 studies, 500 women), while the non-obese group showed a possible benefit from metformin, with high heterogeneity (OR 1.71, 95% CI 1.00 to 2.94; I² = 78%, 3 studies, 241 women; very low-quality evidence). However, due to the very low quality of the evidence we cannot draw any conclusions. Among obese women taking metformin there may be lower rates of clinical pregnancy (OR 0.34, 95% CI 0.21 to 0.55; I² = 0%; 2 studies, 500 women; low-quality evidence) and ovulation (OR 0.29, 95% CI 0.20 to 0.43; I² = 0%; 2 studies, 500 women; low-quality evidence) while among non-obese women, the metformin group may have more pregnancies (OR 1.56, 95% CI 1.06 to 2.29; I² = 26%; 6 studies, 530 women; low-quality evidence) and no clear difference in ovulation rates (OR 0.80, 95% CI 0.52 to 1.25; I² = 0%; 5 studies, 352 women; low-quality evidence). We are uncertain whether there is a difference in miscarriage rates between the groups (overall: OR 0.92, 95% CI 0.51 to 1.66; I² = 36%; 6 studies, 781 women; low-quality evidence) and no studies reported gastrointestinal side effects.

AUTHORS' CONCLUSIONS

Our updated review suggests that metformin may be beneficial over placebo for live birth however, more women probably experience gastrointestinal side effects. We are uncertain if metformin plus CC improves live birth rates compared to CC alone, but gastrointestinal side effects are probably increased with combined therapy. When metformin was compared with CC, data for live birth were inconclusive, and the findings were limited by lack of evidence. Results differed by body mass index (BMI), emphasising the importance of stratifying results by BMI. No studies reported gastrointestinal side effects in this comparison. Due to the low quality of the evidence, we are uncertain of the effect of metformin on miscarriage in all three comparisons.

Effect of Metformin on a Preeclampsia-Like Mouse Model Induced by High-Fat Diet

BACKGROUND

Metformin has been reported to decrease insulin resistance and is associated with a lower risk of pregnancy-induced hypertension and preeclampsia. It is widely accepted that the placenta plays a crucial role in the development of preeclampsia. Our aim is to explore the effect of metformin on preeclampsia.

STUDY DESIGN

We examined control diet-fed (isocaloric diet) pregnant mice (CTRL group), pregnant mice fed a high-fat diet (HF group), and high-fat-diet-fed pregnant mice treated with metformin (HF-M group). The HF mice were fed a high-fat diet six weeks before pregnancy to establish a preeclampsia-like model; then, the group was randomly divided into a HF group and a HF-M group after pregnancy. Blood pressure, urine protein, pregnancy outcomes, protein expression, and histopathological changes in the placentas of all groups were examined and statistically analysed.

RESULTS

We observed that metformin significantly improved high blood pressure, proteinuria, and foetal and placental weights in the HF-M group compared with the HF group. Metformin significantly improved placental labyrinth and foetal vascular development in preeclampsia. In addition, metformin effectively increased matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) levels in the placenta.

CONCLUSIONS

Our results suggest that metformin can improve preeclamptic symptoms and pregnancy outcomes.

Real-World Experience of Adding Metformin in Pregnant Women with Type 1 Diabetes in a Chinese Population: A Retrospective Cohort

INTRODUCTION

Glycemic control in pregnant women with type 1 diabetes (T1D) is challenging with only insulin, and the incidence rate of adverse perinatal outcomes is high. Increasing data have indicated the safety and effect of metformin in pregnancy; however, no relevant data are available in pregnant women with T1D. We aimed to investigate glycemic control and perinatal outcomes in pregnant women with T1D in a Chinese population and explored the role of metformin in these patients.

METHODS

We obtained data of 38 pregnant women with T1D who received regular antenatal care and delivered at Peking Union Medical College Hospital (PUMCH) between 1 January 2006 and 31 May 2018. The perinatal outcomes of T1D patients who added metformin as adjunct treatment and those who remained on insulin-alone therapy were compared retrospectively.

RESULTS

Being overweight was common (35.1%) in pregnant women with T1D. On average, the insulin dose increased by 35.30 ± 22.60 unit/day during pregnancy. The cesarean delivery rate was high (65.8%), and fetal macrosomia was the main reason. The change of HbA1c in the metformin-insulin group was more prominent than in the insulin-only group (- 1.47 ± 1.17% vs. - 0.90 ± 1.13%, p = 0.05). There was no statistically significant difference in perinatal outcomes between the two groups.

CONCLUSIONS

The incidence of adverse perinatal outcomes in pregnant women with T1D was high. This study innovatively suggested that metformin could be safe and could contribute to improving glucose management in pregnant women with T1D.

Use of metformin to treat pregnant women with polycystic ovary syndrome (PregMet2): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Women with polycystic ovary syndrome (PCOS) have an increased risk of pregnancy complications. Epi-analysis of two previous randomised controlled trials that compared metformin with placebo during pregnancy in women with PCOS showed a significant reduction in late miscarriages and preterm births in the metformin group. The aim of this third randomised trial (PregMet2) was to test the hypothesis that metformin prevents late miscarriage and preterm birth in women with PCOS.

METHODS

PregMet2 was a randomised, placebo-controlled, double-blind, multicentre trial done at 14 hospitals in Norway, Sweden, and Iceland. Singleton pregnant women with PCOS aged 18-45 years were eligible for inclusion. After receiving information about the study at their first antenatal visit or from the internet, women signed up individually to participate in the study. Participants were randomly assigned (1:1) to receive metformin or placebo by computer-generated random numbers. Randomisation was in blocks of ten for each country and centre; the first block had a random size between one and ten to assure masking. Participants were assigned to receive oral metformin 500 mg twice daily or placebo during the first week of treatment, which increased to 1000 mg twice daily or placebo from week 2 until delivery. Placebo tablets and metformin tablets were identical and participants and study personnel were masked to treatment allocation. The primary outcome was the composite incidence of late miscarriage (between week 13 and week 22 and 6 days) and preterm birth (between week 23 and week 36 and 6 days), analysed in the intention-to-treat population. Secondary endpoints included the incidence of gestational diabetes, preeclampsia, pregnancy-induced hypertension, and admission of the neonate to the neonatal intensive care unit. We also did a post-hoc individual participant data analysis of pregnancy outcomes, pooling data from the two previous trials with the present study. The study was registered with ClinicalTrials.gov, number NCT01587378, and EudraCT, number 2011-002203-15.

FINDINGS

The study took place between Oct 19, 2012, and Sept 1, 2017. We randomly assigned 487 women to metformin (n=244) or placebo (n=243). In the intention-to-treat analysis, our composite primary outcome of late miscarriage and preterm birth occurred in 12 (5%) of 238 women in the metformin group and 23 (10%) of 240 women in the placebo group (odds ratio [OR] 0·50, 95% CI 0·22-1·08; p=0·08). We found no significant differences for our secondary endpoints, including incidence of gestational diabetes (60 [25%] of 238 women in the metformin group vs 57 [24%] of 240 women in the placebo group; OR 1·09, 95% CI 0·69-1·66; p=0·75). We noted no substantial between-group differences in serious adverse events in either mothers or offspring, and no serious adverse events were considered drug-related by principal investigators. In the post-hoc pooled analysis of individual participant data from the present trial and two previous trials, 18 (5%) of 397 women had late miscarriage or preterm delivery in the metformin group compared with 40 (10%) of 399 women in the placebo group (OR 0·43, 95% CI 0·23-0·79; p=0·004).

INTERPRETATION

In pregnant women with PCOS, metformin treatment from the late first trimester until delivery might reduce the risk of late miscarriage and preterm birth, but does not prevent gestational diabetes.

FUNDING

Research Council of Norway, Novo Nordisk Foundation, St Olav's University Hospital, and Norwegian University of Science and Technology.

Generational Health Impact of PCOS on Women and their Children

Polycystic ovary syndrome (PCOS) is a metabolic disorder with reproductive consequences. Hence, the synergy of the dual maternal challenges of difficulties with conception, set on a background of metabolic disorder and inflammation, understandably leads to increased obstetric risk for the woman. Furthermore, she is more likely than her peers to require assistance with conception, either through induction of ovulation with the attendant risk of a multiple gestation, or in vitro fertilization (IVF) with its recognized increased obstetric risk for woman and her child. The increased obstetric risk for a woman with PCOS is manifested with an increased rate of miscarriage, gestational diabetes, hypertensive disorder and premature delivery. These obstetric complications are due to impairment of placental function, systemic inflammation and metabolic disorder and are markers for the woman herself of her predisposition to cardiometabolic disorder in later life. Consequently, it is inevitable that this environment may induce changes in the fetus during pregnancy, leading to an intergenerational risk from maternal PCOS.

Prevention of pre-eclampsia after infertility treatment: Preconceptional minimalisation of risk factors

Although an increased risk of pre-eclampsia in pregnancies conceived after infertility treatment has been reported, it remains unknown whether preconceptional minimalisation of known risk factors would help in preventing pre-eclamsia. Obesity and preconceptional blood pressure are discussed as major risks for the development of pre-eclampsia and low doses of aspirins, folic acid, statins and metformin are discussed as potential preventive treatments to decrease the risk of pre-eclampsia. In the present review we discuss whether present-day reproductive medicine could progress towards complication-free pregnancy.

Gestational diabetes risk factors and long-term consequences for both mother and offspring: a literature review

INTRODUCTION

Established risk factors for gestational diabetes mellitus (GDM) include ethnicity, obesity, and family history of diabetes. Untreated GDM patients have higher rates of maternal and perinatal morbidity. GDM is an independent risk factor for future longer-term risk of type 2 diabetes mellitus (T2DM), metabolic syndrome, cardiovascular morbidity, malignancies, ophthalmic, psychiatric, and renal disease in the mother. Offspring risk long-term adverse health outcomes, including T2DM, subsequent obesity, impacted neurodevelopmental outcome, increased neuropsychiatric morbidity, and ophthalmic disease.

AREAS COVERED

We critically review data from retrospective, prospective, and meta-analysis studies pertaining to established GDM risk factors, complications during pregnancy and birth (both mother and offspring), and long-term consequences (both mother and offspring).

EXPERT COMMENTARY

Many of the adverse consequences of GDM might be avoided with proper management and treatment. Patients belonging to high-risk ethnic groups, and/or with body mass index ≥ 25 kg/m², and/or known history of diabetes in first-degree relatives may benefit from universal screening and diagnostic criteria proposed by the International Association of Diabetes and Pregnancy Study Group (IADPSG). The IADPSG one-step method has several advantages, including simplicity of execution, greater patient-friendliness, and higher diagnostic accuracy. Additionally, evidence suggests that the recent increased popularity of bariatric surgery will help to decrease GDM rates over next 5 years. Similarly, metformin may be useful for treating and preventing obstetrical complications in confirmed GDM patients.

Synthesis and Analysis of Copper Neem (Azadirechta Indica) Soap-Nitro and Ethoxy Benzothiazole Complexes for Anti-Bacterial Activity Related with Skin Diseases

The solid copper(II) soap derived from Neem (Azadirechta Indica)oil and its complex with ligand containing nitrogen, sulphur and oxygen atoms like 2-amino -6-nitro benzothiazole and 2-amino- 6-ethoxy benzothiazole have been synthesized and characterised by elemental analysis, IR spectroscopy and biological studies. From the analytical data, the stoichiometry of the complex has been observed to be 1:1 (metal:ligand). The derived compounds were found active against Staphylococcus aureus,Coagulase-negative staphylococci (CoNs), Acinetobacter baumanii, Pseudomonas aeruginosa and micrococcus bacteria. These findings have high medical, industrial and economic significance as copper (II) soap and copper (II) soap complex could be harnessed in the formulation of medicated soaps.

Metformin in Reproductive Biology

Initially produced in Europe in 1958, metformin is still one of the most widely prescribed drugs to treat type II diabetes and other comorbidities associated with insulin resistance. Metformin has been shown to improve fertility outcomes in females with insulin resistance associated with polycystic ovary syndrome (PCOS) and in obese males with reduced fertility. Metformin treatment reinstates menstrual cyclicity, decreases the incidence of cesareans, and limits the number of premature births. Notably, metformin reduces steroid levels in conditions associated with hyperandrogenism (e.g., PCOS and precocious puberty) in females and improves fertility of adult men with metabolic syndrome through increased testosterone production. While the therapeutical use of metformin is considered to be safe, in the last 10 years some epidemiological studies have described phenotypic differences after prenatal exposure to metformin. The goals of this review are to briefly summarize the current knowledge on metformin focusing on its effects on the female and male reproductive organs, safety concerns, including the potential for modulating fetal imprinting via epigenetics.

Pharmacotherapy for hyperglycemia in pregnancy - Do oral agents have a place?

Diabetes is a frequent condition in pregnancy and achieving adequate glycemic control is of paramount importance. Insulin treatment is the gold standard, oral agents are more attractive, but their safety and efficiency should be a prerequisite for their use. We have more information regarding treatment of women with gestational diabetes mellitus where glyburide can induce a picture of fetal hyperinsulinism (higher birthweight and more neonatal hypoglycemia) whereas metformin requires supplemental insulin in a larger proportion of women but achieves satisfactory perinatal outcomes with the exception of preterm birth. Information in patients with Type 2 Diabetes Mellitus is much more limited but also favors metformin. Combinations provide additional possibilities. However, as to long-term outcomes, we have no information on the impact of exposure to glyburide and it is still unclear if in utero exposure to metformin will have any effect on the offspring and the direction of this effect. Women prefer oral agents, indicating the need of additional studies.

Long-Term Effects of Oral Antidiabetic Drugs During Pregnancy on Offspring: A Systematic Review and Meta-analysis of Follow-up Studies of RCTs

INTRODUCTION

Antidiabetic drugs (OADs) are increasingly prescribed to treat hyperglycaemia during pregnancy in women with gestational diabetes mellitus (GDM) or polycystic ovary syndrome (PCOS), even though long-term effects on offspring are unknown. This systematic review summarises the evidence of follow-up studies of randomised controlled trials (RCTs) reporting on long-term effects of prenatal exposure to OADs on offspring.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched from inception to April 2018 for the concepts antidiabetic agents and prenatal exposure (or pregnancy and offspring/child) in combination with an RCT search filter. RCTs evaluating post-neonatal health effects in offspring and comparing maternal treatment with an OAD with no treatment, placebo, an alternative OAD or insulin during pregnancy were eligible for inclusion. Two independent researchers selected, extracted and assessed the data. Meta-analyses were performed using a random effects model and the Cochrane Collaboration's risk of bias tool was used for quality assessment.

RESULTS

Ten studies were included, with a maximal follow-up duration of 9 years, comprising 778 children of mothers with GDM or PCOS who were randomised to either metformin or insulin/placebo during pregnancy. Meta-analysis showed that children prenatally exposed to metformin were heavier compared to controls (standardised mean difference (SMD) 0.26 [95% CI 0.11-0.41]), but not taller (SMD 0.10 [95% CI -0.14-0.33]). Additionally, offspring body mass index (BMI) z scores did not differ according to metformin exposure (mean difference 0.30 [95% CI -0.01-0.61]). Individual small studies reported that prenatal exposure to metformin was associated with greater mid-upper arm, head and waist circumferences, biceps skinfolds, waist-to-height ratio, more arm fat, higher fasting glucose, ferritin and lower LDL cholesterol in offspring.

CONCLUSION

Prenatal exposure to metformin is associated with increased offspring weight, but not with height or BMI. Larger follow-up studies are needed to confirm and look into the implications of these findings. Plain language summary available for this article.

Pregestational Diabetes in Pregnancy

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

Gestational diabetes mellitus: Multi-disciplinary treatment approaches

Gestational diabetes mellitus (GDM) is the most common metabolic disease of pregnancy, associated with several perinatal complications. Adequate glycemic control has been proved to decrease risk of GDM-related complications. Several studies have shown the beneficial effect of exercise and medical nutrition treatment on glycemic and weight control in GDM-affected women. Moreover, pharmacological agents, such as insulin and specific oral anti-diabetic agents can be prescribed safely during pregnancy, decreasing maternal blood glucose and, thus, perinatal adverse outcomes. Multi-disciplinary treatment approaches that include both lifestyle modifications (medical nutritional therapy and daily physical exercise) and pharmacological treatment, in cases of failure of the former, constitute the most effective approach. Insulin is the gold standard pharmacological agent for GDM treatment. Metformin and glyburide are two oral anti-diabetic agents that could serve as alternative, although not equal in terms of effectiveness and safety, treatment for GDM. As studies on short-term safety of metformin are reassuring, in some countries it is considered as first-line treatment for GDM management. More studies are needed to investigate the long-term effects on offspring. As safety issues have been raised on the use of glyburide during pregnancy, it must be used only when benefits surpass possible risks.

Pregnancy outcome after first-trimester exposure to metformin: A prospective cohort study

The aim of this study was to evaluate the risk of major birth defects and spontaneous abortion after metformin use during the first trimester of pregnancy. We conducted an observational cohort study comparing pregnancies with metformin treatment during the first trimester with non-exposed women matched for BMI and year of enrolment. Pregnancies were prospectively ascertained in the German Embryotox pharmacovigilance database between 2004 and 2014. The study sample included 336 pregnancies with metformin exposure for PCOS and fertility disorders (56.8%), diabetes (25.9%) and insulin resistance (14.9%) and 1011 matched controls. Independent of the treatment indication, neither the rate of major birth defects (OR adjusted 0.58, 95% CI 0.3-1.3) nor of spontaneous abortions (HR adjusted 0.95, 95% CI 0.6-1.5) was significantly increased among metformin exposed. Our study supports the evidence that metformin does not carry a developmental risk for the fetus when used during the first trimester.

Brown adipose tissue development and function and its impact on reproduction

Although brown adipose tissue (BAT) is one of the smallest organs in the body, it has the potential to have a substantial impact on both heat production as well as fat and carbohydrate metabolism. This is most apparent at birth, which is characterised with the rapid appearance and activation of the BAT specific mitochondrial uncoupling protein (UCP)1 in many large mammals. The amount of brown fat then gradually declines with age, an adaptation that can be modulated by the thermal environment. Given the increased incidence of maternal obesity and its potential transmission to the mother's offspring, increasing BAT activity in the mother could be one mechanism to prevent this cycle. To date, however, all rodent studies investigating maternal obesity have been conducted at standard laboratory temperature (21°C), which represents an appreciable cold challenge. This could also explain why offspring weight is rarely increased, suggesting that future studies would benefit from being conducted at thermoneutrality (~28°C). It is also becoming apparent that each fat depot has a unique transcriptome and show different developmental pattern, which is not readily apparent macroscopically. These differences could contribute to the retention of UCP1 within the supraclavicular fat depot, the most active depot in adult humans, increasing heat production following a meal. Despite the rapid increase in publications on BAT over the past decade, the extent to which modifications in diet and/or environment can be utilised to promote its activity in the mother and/or her offspring remains to be established.

Maternal polycystic ovarian syndrome and early offspring development

STUDY QUESTION

Is maternal polycystic ovarian syndrome (PCOS) associated with developmental delays in offspring?

SUMMARY ANSWER

Offspring of mothers with PCOS were at higher risk of failure on the Ages and Stages Questionnaire (ASQ).

WHAT IS KNOWN ALREADY

There is growing evidence that offspring of mothers with PCOS may be at higher risk for developmental disorders due to potential exposure to hyperandrogenism and insulin resistance. Few studies exist regarding maternal PCOS and early childhood development in the USA.

STUDY DESIGN, SIZE, DURATION

The Upstate KIDS Study is a population-based prospective cohort study of infants born between 2008 and 2010 in New York State (excluding New York City), originally designed to study-and finding no impact of-infertility treatment exposure on child development. Children were followed up to 36 months of age. In all, 4453 mothers completed one or more developmental screening instruments for 5388 children (35.5% twins) up to 36 months of age.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In our study, 458 mothers (10.3%) reported a healthcare provider's diagnosis of PCOS, as well as the related treatment received, on the baseline study questionnaire. Parents completed the ASQ on their child's development at 4, 8, 12, 18, 24, 30 and 36 months of age to assess fine motor, gross motor, communication, personal-social functioning and problem-solving cognitive domains. We used generalized linear mixed models to estimate odds ratios (OR) between PCOS diagnosis and failures in the ASQ adjusted for maternal age, race, BMI, education, marital status, smoking, alcohol consumption, diabetes, insurance and plurality.

MAIN RESULTS AND THE ROLE OF CHANCE

Diagnosis of PCOS was associated with increased risk of the offspring failing the fine motor domain (adjusted odds ratio (aOR) = 1.77; 95% CI: 1.09, 2.89), largely driven by higher risk in female singletons (aOR = 2.23; 1.16, 4.29). Twins of mothers with PCOS had higher risk of failing the communication (aOR = 1.94; 1.19, 3.18) and personal-social functioning (aOR = 1.76; 1.12, 2.77) domains compared to twins born to mothers without PCOS. Compared to offspring of women without PCOS, offspring of women who reported receiving no treatment for their PCOS had a stronger association with failing the ASQ (aOR = 1.68; 0.95, 2.75) than the association among offspring of women who reported PCOS treatment (aOR = 1.16; 0.79, 1.73).

LIMITATIONS, REASONS FOR CAUTION

Further study is needed to confirm the role of maternal PCOS in early offspring development with provider-validated diagnosis of PCOS.

WIDER IMPLICATIONS OF THE FINDINGS

If confirmed, these findings suggest that offspring of women with PCOS may be at increased risk for developmental delay.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD; contracts HHSN275201200005C, #HHSN267200700019C). Authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

Not applicable.