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

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.

Developmental metformin exposure does not rescue physiological impairments derived from early exposure to altered maternal metabolic state in offspring mice

OBJECTIVE

The incidence of gestational diabetes mellitus (GDM) and metabolic disorders during pregnancy are increasing globally. This has resulted in increased use of therapeutic interventions such as metformin to aid in glycemic control during pregnancy. Even though metformin can cross the placental barrier, its impact on offspring brain development remains poorly understood. As metformin promotes AMPK signaling, which plays a key role in axonal growth during development, we hypothesized that it may have an impact on hypothalamic signaling and the formation of neuronal projections in the hypothalamus, the key regulator of energy homeostasis. We further hypothesized that this is dependent on the metabolic and nutritional status of the mother at the time of metformin intervention. Using mouse models of maternal overnutrition, we aimed to assess the effects of metformin exposure on offspring physiology and hypothalamic neuronal circuits during key periods of development.

METHODS

Female C57BL/6N mice received either a control diet or a high-fat diet (HFD) during pregnancy and lactation periods. A subset of dams was fed a HFD exclusively during the lactation. Anti-diabetic treatments were given during the first postnatal weeks. Body weights of male and female offspring were monitored daily until weaning. Circulating metabolic factors and molecular changes in the hypothalamus were assessed at postnatal day 16 using ELISA and Western Blot, respectively. Hypothalamic innervation was assessed by immunostaining at postnatal days 16 and 21.

RESULTS

We identified alterations in weight gain and circulating hormones in male and female offspring induced by anti-diabetic treatment during the early postnatal period, which were critically dependent on the maternal metabolic state. Furthermore, hypothalamic agouti-related peptide (AgRP) and proopiomelanocortin (POMC) neuronal innervation outcomes in response to anti-diabetic treatment were also modulated by maternal metabolic state. We also identified sex-specific changes in hypothalamic AMPK signaling in response to metformin exposure.

CONCLUSION

We demonstrate a unique interaction between anti-diabetic treatment and maternal metabolic state, resulting in sex-specific effects on offspring brain development and physiological outcomes. Overall, based on our findings, no positive effect of metformin intervention was observed in the offspring, despite ameliorating effects on maternal metabolic outcomes. In fact, the metabolic state of the mother drives the most dramatic differences in offspring physiology and metformin had no rescuing effect. Our results therefore highlight the need for a deeper understanding of how maternal metabolic state (excessive weight gain versus stable weight during GDM treatment) affects the developing offspring. Further, these results emphasize that the interventions to treat alterations in maternal metabolism during pregnancy need to be reassessed from the perspective of the offspring physiology.

A multi-centered trial investigating gestational treatment with ursodeoxycholic acid compared to metformin to reduce effects of diabetes mellitus (GUARD): a randomized controlled trial protocol

BACKGROUND

Each year in the UK, approximately 35,000 women develop gestational diabetes mellitus (GDM). The condition increases the risk of obstetric and neonatal complications for mother and child, including preeclampsia, preterm birth, and large for gestational age babies. Biochemical consequences include maternal hyperglycemia, neonatal hypoglycemia, and dyslipidemia. Metformin is the most commonly used firstline pharmacological treatment. However, there are concerns about its widespread use during pregnancy, due to its limited efficacy and potential safety concerns. Therefore, there is a need for additional therapies that improve both maternal-fetal glucose and lipid metabolism. Ursodeoxycholic acid (UDCA) is not currently used for treatment for GDM. However, it can improve glucose control in type 2 diabetes, and it improves fetal lipid profiles in gestational cholestasis. Consequentially, it is hypothesized that treatment with UDCA for women with GDM may improve both maternal metabolism and neonatal outcomes. The primary outcome of this trial is to assess the efficacy of UDCA compared with metformin to improve glucose levels in women with GDM.

METHODS

The trial is a two-armed, open-label, multi-center, randomized controlled trial. Women are eligible if they have been diagnosed with GDM by an oral glucose tolerance test between 24 + 0 and 30 + 6 weeks' gestation, and if they require pharmacological intervention. In total, 158 pregnant women will be recruited across seven NHS Trusts in England and Wales. Women who consent will be recruited and randomized to either metformin or UDCA, which will be taken daily until the birth of their baby. Maternal and neonatal blood samples will be taken to evaluate the impact of the treatments on maternal glucose control, and maternal and neonatal lipid metabolism. Maternal and fetal outcomes will be evaluated, and acceptability of UDCA compared with metformin will be assessed.

DISCUSSION

This trial has the potential to identify a potential new treatment for women with GDM. If successful, a future large multi-center trial will be designed to investigate where decisions can be personalized to identify which women will respond more effectively to UDCA than alternatives to improve maternal and baby outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04407650.

Role of Beta Cell Function and Insulin Resistance in the Development of Gestational Diabetes Mellitus

Background: Gestational diabetes mellitus (GDM) is a pregnancy complication characterized by second trimester hyperglycemia. Untreated, GDM is related to an increased risk for adverse pregnancy outcomes. Both beta cell dysfunction and insulin resistance underlie impaired glucose tolerance. Understanding the dominant mechanism predisposing to GDM may be important to provide effective treatment in order to improve perinatal outcomes. We hypothesize that insulin resistance rather that beta cell dysfunction predisposes to GDM. Methods: A 75g oral glucose tolerance test (OGTT) was performed on 2112 second-trimester pregnant women to determine the relationship between insulin resistance (HOMA-IR), beta cell function (HOMA-β), and the prevalence of abnormal glucose handling. Results: High insulin resistance raised the risk of GDM (relative risk (RR) 6.1, 95% confidence interval (CI) (4.4–8.5)), as did beta cell dysfunction (RR 3.8, 95% CI (2.7–5.4)). High insulin resistance, but not beta cell function, enhances the necessity for additional glucose lowering medication on top of a low carbohydrate diet in women diagnosed with GDM. Conclusions: Both high insulin resistance and beta cell dysfunction increase the risk of GDM. As increased insulin resistance, rather than beta cell function, is related to an insufficient response to a low carbohydrate diet, we speculate that insulin sensitizers rather than insulin therapy may be the most targeted therapeutic modality in diet-insensitive GDM.

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

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

Environmental exposure during pregnancy and the risk of childhood allergic diseases

BACKGROUND

Allergic diseases are one of the most common and important diseases that can exert hazardous effects on children's health. The prevalence of allergic diseases in childhood is gradually increasing all over the world in recent decades. Known causes of these diseases include anomalous immune responses and allergic inflammatory reactions, but the causes of allergic diseases in childhood are complex.

DATA SOURCES

PubMed, Cochrane Library, Embase and Web of Science were searched for articles focusing on environmental exposure during pregnancy and the risk of childhood allergic diseases, including asthma and atopic dermatitis, and the possible underlying mechanism.

RESULTS

In terms of environmental factors, allergic diseases in childhood are closely related to environmental chemical exposure during pregnancy, including bisphenols, phthalates acid esters, perfluorochemicals, polybrominated diphenyl ethers, and polychlorinated biphenyls. However, allergic diseases in childhood are also closely associated with maternal dietary nutrition, maternal intake of drugs, such as acetylsalicylic acid (aspirin), paracetamol and antibiotics, and maternal lifestyle.

CONCLUSIONS

Several harmful environmental factors during pregnancy can result in the interruption of the function of helper T cells (Th1/Th2), cytokines and immunoglobulins and may activate allergic reactions, which can lead to allergic diseases during childhood.

Maternal PCOS status and metformin in pregnancy: Steroid hormones in 5-10 years old children from the PregMet randomized controlled study

Objective

Polycystic ovary syndrome (PCOS) is a common endocrine disorder, with potential effects on offspring both genetically and through altered intrauterine environment. Metformin, which ameliorate hormonal disturbances in non-pregnant women with PCOS is increasingly used in pregnancy. It passes the placenta, and the evidence on potential consequences for offspring endocrine development is scarce. We explore the potential effects of maternal PCOS status and intrauterine metformin exposure on offspring steroid hormone levels.

Design

This is a follow-up study of 5–10 years old children from the PregMet-study–a randomized controlled trial comparing metformin (2000 mg/day) to placebo during PCOS pregnancies. Of the 255 children invited, 117 (46%) were included.

Methods

There was no intervention in this follow-up study. Outcomes were serum levels of androstenedione, testosterone, SHBG, cortisol, 17-hydroxyprogesterone, 11-deoxycortisol and calculated free testosterone converted to gender-and age adjusted z-scores from a Norwegian reference population. These were compared in i) placebo-exposed children versus children from the reference population (z-score zero) by the deviation in z-score by one-sample t-tests and ii) metformin versus placebo-exposed children by two-sample t-tests. Holm-Bonferroni adjustments were performed to account for multiple endpoints.

Results

Girls of mothers with PCOS (n = 30) had higher mean z-scores of androstenedione (0.73 (95% confidence interval (CI) 0.41 to 1.06), p<0.0001), testosterone (0.76 (0.51 to 1.00), p<0.0001), and free testosterone (0.99 (0.67 to 1.32), p<0.0001) than the reference population. Metformin-exposed boys (n = 31) tended to have higher 11-deoxycortisol z-score than placebo-exposed boys (n = 24) (mean difference 0.65 (95% CI 0.14–1.17), p = 0.014).

Conclusion

Maternal PCOS status was associated with elevated androgens in 5- to 10-year-old daughters, which might indicate earlier maturation and increased risk of developing PCOS. An impact of metformin in pregnancy on steroidogenesis in children born to mothers with PCOS cannot be excluded. Our findings need confirmation in studies that include participants that have entered puberty.

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.

Cord serum metabolome and birth weight in patients with gestational diabetes treated with metformin, insulin, or diet alone

INTRODUCTION

Recent research has demonstrated the benefits of metformin treatment in gestational diabetes (GDM) on short-term pregnancy outcomes (including excessive fetal growth and pre-eclampsia), but its effects on fetal metabolism remain mostly unknown. Our aim was to study the effects of metformin treatment compared with insulin or diet on the cord serum metabolome and also to assess how these metabolites are related to birth weight (BW) in pregnancies complicated by GDM.

RESEARCH DESIGN AND METHODS

Cord serum samples were available from 113, 97, and 98 patients with GDM treated with diet, insulin, and metformin, respectively. A targeted metabolome was measured using nuclear magnetic resonance spectroscopy. The patients in the metformin and insulin groups had participated in a previous randomized trial (NCT01240785).

RESULTS

Cord serum alanine was elevated in the metformin group (0.53 mmol/L) compared with the insulin (0.45 mmol/L, p<0.001) and the diet groups (0.46 mmol/L, p<0.0001). All other measured metabolites were similar between the groups. The triglyceride (TG)-to-phosphoglyceride ratio, average very low-density lipoprotein particle diameter, docosahexaenoic acid, omega-3 fatty acids (FAs), and ratios of omega-3 and monounsaturated FA to total FA were inversely related to BW. The omega-6-to-total-FA and omega-6-to-omega-3-FA ratios were positively related to BW. Cholesterol in very large and large high-density lipoprotein (HDL) was positively (p<0.01) associated with BW when adjusted for maternal prepregnancy body mass index, gestational weight gain, glycated hemoglobin, and mode of delivery.

CONCLUSIONS

Metformin treatment in GDM leads to an increase in cord serum alanine. The possible long-term implications of elevated neonatal alanine in this context need to be evaluated in future studies. Although previous studies have shown that metformin increased maternal TG levels, the cord serum TG levels were not affected. Cord serum HDL cholesterol and several FA variables are related to the regulation of fetal growth in GDM. Moreover, these associations seem to be independent of maternal confounding factors.

TRIAL REGISTRATION NUMBER

NCT01240785.

Therapeutic Potentials of Low-Dose Tacrolimus for Aberrant Endometrial Features in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a major anovulatory infertility affecting a great proportion of women of childbearing age and is associated with obesity, insulin resistance and chronic inflammation. Poor endometrial receptivity and recurrent implantation failure are major hurdles to the establishment of pregnancy in women with PCOS. The accumulating body of evidence obtained from experimental and clinical studies suggests a link between inherent adaptive and innate immune irregularities and aberrant endometrial features in PCOS. The use of conventional therapeutic interventions such as lifestyle modification, metformin and ovarian stimulation has achieved limited clinical success in restoring ovulation and endometrial receptivity in women with PCOS. Unlike other immunosuppressive drugs prescribed in the clinical management of autoimmune and inflammatory disorders that may have deleterious effects on fertility and fetal development, preclinical studies in mice and in women without PCOS but with repeated implantation failure revealed potential therapeutic benefits for the use of low-dose tacrolimus in treating female infertility. Improved systemic and ovarian immune functions, endometrial progesterone receptor and coreceptor expressions and uterine vascular adaptation to pregnancy were among features of enhanced progesterone-receptor sensitivity in the low-dose tacrolimus-treated mouse model of the disease. In this review, we have compiled available experimental and clinical data in literature on endometrial progesterone resistance and current therapeutic options, as well as mechanisms of actions and reported outcomes relevant to the potential therapeutic benefits for the use of low-dose tacrolimus in treating PCOS-associated female infertility.

Management of Women with Polycystic Ovary Syndrome During Pregnancy

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive age women and is associated with subfertility and adverse perinatal outcomes, which may include early pregnancy loss, gestational diabetes mellitus, hypertensive spectrum disorder, preterm birth, fetal growth disorders, and cesarean deliveries. The phenotypic heterogeneity, different diagnostic criteria, and PCOS-related conditions that women enter pregnancy with have limited evidenced-based studies and guidelines to reduce pregnancy complications among this high-risk population. This review summarizes the available evidence on the approach and management of women with PCOS preconception, prenatal, and postpartum.

Gestational Diabetes Mellitus and Developmental Programming

During normal pregnancy, increased insulin resistance acts as an adaptation to enhance materno-foetal nutrient transfer and meet the nutritional needs of the developing foetus, particularly in relation to glucose requirements. However, about 1 in 6 pregnancies worldwide is affected by the inability of the mother's metabolism to maintain normoglycaemia, with the combination of insulin resistance and insufficient insulin secretion resulting in gestational diabetes mellitus (GDM). A growing body of epidemiologic work demonstrates long-term implications for adverse offspring health resulting from exposure to GDM in utero. The effect of GDM on offspring obesity and cardiometabolic health may be partly influenced by maternal obesity; this suggests that improving glucose and weight control during early pregnancy, or better still before conception, has the potential to lessen the risk to the offspring. The consequences of GDM for microbiome modification in the offspring and the impact upon offspring immune dysregulation are actively developing research areas. Some studies have suggested that GDM impacts offspring neurodevelopmental and cognitive outcomes; confirmatory studies will need to separate the effect of GDM exposure from the complex interplay of social and environmental factors. Animal and human studies have demonstrated the role of epigenetic modifications in underpinning the predisposition to adverse health in offspring exposed to suboptimal hyperglycaemic in utero environment. To date, several epigenome-wide association studies in human have extended our knowledge on linking maternal diabetes-related DNA methylation marks with childhood adiposity-related outcomes. Identification of such epigenetic marks can help guide future research to develop candidate diagnostic biomarkers and preventive or therapeutic strategies. Longer-term interventions and longitudinal studies will be needed to better understand the causality, underlying mechanisms, or impact of GDM treatments to optimize the health of future generations.

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.

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.

The 2019 Flemish consensus on screening for overt diabetes in early pregnancy and screening for gestational diabetes mellitus

Screening for gestational diabetes mellitus (GDM) is important to improve pregnancy outcomes and to prevent type 2 diabetes after pregnancy. The 'International Association of Diabetes and Pregnancy Study Groups' (IADPSG) recommends a universal one-step approach with the 75 g oral glucose tolerance test (OGTT) for screening of GDM. The IADPSG recommendation remains controversial due to the important increase in GDM prevalence and increased workload. After review of the latest evidence and based on data from the 'Belgian Diabetes in Pregnancy' study, members of the Diabetes Liga, the Flemish associations of general physicians (Domus Medica), obstetricians (VVOG), midwives (VVOB), diabetes nurse educators (BVVDV) and clinical chemists (RBSLM) have reached a new consensus on screening for GDM in Flanders. This new consensus recommends universal screening for overt diabetes when planning pregnancy or at the latest at first prenatal contact, preferably by measuring the fasting plasma glucose by using the same diagnostic criteria as in the non-pregnant state. In women with impaired fasting glycaemia, but also in normoglycemic obese women and women with a previous history of GDM, lifestyle counselling is advised with screening for GDM with a 75 g OGTT at 24 weeks. In all other women, we recommend a two-step screening strategy with a 50 g glucose challenge test (GCT) at 24 weeks followed by a 75 g OGTT when the glucose level 1 hour after the GCT ≥130 mg/dl. Diagnosis of GDM is made using the IADPSG criteria for GDM. Postpartum screening for subsequent glucose abnormalities should be advocated and organized for every woman with GDM.

Metformin use in obese mothers is associated with improved cardiovascular profile in the offspring

BACKGROUND

Maternal obesity increases the risk for pregnancy complications and adverse neonatal outcome and has been associated with long-lasting adverse effects in the offspring, including increased body fat mass, insulin resistance, and increased risk for premature cardiovascular disease. Lifestyle interventions in pregnancy have produced no or modest effects in the reduction of adverse pregnancy outcomes in obese mothers. The Metformin in Obese Pregnant Women trial was associated with reduced adverse pregnancy outcomes and had no effect on birthweight. However, the long-term implications of metformin on the health of offspring remain unknown.

OBJECTIVE

The purpose of this study was to assess whether prenatal exposure to metformin can improve the cardiovascular profile and body composition in the offspring of obese mothers.

STUDY DESIGN

In 151 children from the Metformin in Obese Pregnant Women trial, body composition, peripheral blood pressure, and arterial pulse wave velocity were measured. Central hemodynamics (central blood pressure and augmentation index) were estimated with the use of an oscillometric device. Left ventricular cardiac function and structure were assessed by echocardiography.

RESULTS

Children were 3.9±1.0 years old, and 77 of them had been exposed to metformin prenatally. There was no significant difference in peripheral blood pressure, arterial stiffness, and body composition apart from gluteal and tricep circumferences, which were lower in the metformin group (P<.05). The metformin group, compared with the placebo group, had lower central hemodynamics (mean adjusted decrease, -0.707 mm Hg for aortic systolic blood pressure, -1.65 mm Hg for aortic pulse pressure, and -2.68% for augmentation index; P<.05 for all) and lower left ventricular diastolic function (adjusted difference in left atrial area, -0.525 cm², in isovolumic relaxation time, -0.324 msec, and in pulmonary venous systolic wave, 2.97 cm/s; P<.05 for all). There were no significant differences in metabolic profile between the groups.

CONCLUSION

Children of obese mothers who were exposed prenatally to metformin, compared with those who were exposed to placebo, had lower central hemodynamic and cardiac diastolic indices. These results suggest that the administration of metformin in obese pregnant women potentially may have a beneficial cardiovascular effect for their offspring.

Metformin during Pregnancy: Effects on Offspring Development and Metabolic Function

Maternal obesity during pregnancy and gestational diabetes mellitus (GDM) are both associated with of several postnatal diseases in the offspring, including obesity, early onset hypertension, diabetes mellitus, and reproductive alterations. Metformin is an oral drug that is being evaluated to treat GDM, obesity-associated insulin resistance, and polycystic ovary syndrome (PCOS) during pregnancy. The beneficial effects of metformin on glycemia and pregnancy outcomes place it as a good alternative for its use during pregnancy. In this line of thought, improving the metabolic status of the pregnant mother by using metformin should avoid the consequences of insulin resistance on the offspring's fetal and postnatal development. However, some human and animal studies have shown that metformin during pregnancy could amplify these alterations and be associated with excessive postnatal weight gain and obesity. In this minireview, we discuss not only the clinical and experimental evidence that supports the benefits of using metformin during pregnancy but also the evidence showing a possible negative impact of this drug on the offspring's development.

Role of metformin in epigenetic regulation of placental mitochondrial biogenesis in maternal diabetes

Adverse maternal environments, such as diabetes and obesity, impair placental mitochondrial function, which affects fetal development and offspring long-term health. The underlying mechanisms and effective interventions to abrogate such effect remain unclear. Our previous studies demonstrated impaired mitochondrial biogenesis in male human placenta of diabetic mothers. In the present studies, epigenetic marks possibly related to mitochondrial biogenesis in placentae of women with diabetes (n = 23) and controls (n = 23) were analyzed. Effects of metformin were examined in human placental explants from a subgroup of diabetic women and in a mouse model of maternal high fat diet feeding. We found that maternal diabetes was associated with epigenetic regulation of mitochondrial biogenesis in human placenta in a fetal sex-dependent manner, including decreased histone acetylation (H3K27 acetylation) and increased promoter methylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). In male placenta, the levels of H3K27 acetylation and PGC-1α promoter methylation correlated significantly with the activity of AMP-activated protein kinase (AMPK). Metformin treatment on male diabetic placental explant activated AMPK and stimulated PGC-1α expression, concomitant with increased H3K27 acetylation and decreased PGC-1α promoter methylation. In vivo, we show that maternal metformin treatment along with maternal high fat diet significantly increased mouse placental abundance of PGC-1α expression and downstream mitochondrial transcription factor A (TFAM) and inhibited maternal high fat diet-impaired placental efficiency and glucose tolerance in offspring. Together, these findings suggest the capability of metformin to stimulate placental mitochondrial biogenesis and inhibit the aberrant epigenetic alterations occurring in maternal diabetes during pregnancy, conferring protective effects on offspring.

Systemic endocrinopathies (thyroid conditions and diabetes): impact on postnatal life of the offspring

Fetal programming may influence childhood and adult life, determining the risk of specific diseases. During earlier stages of pregnancy, the transfer of maternal thyroid hormones to the fetus is vital for adequate neurologic development. The presence of severe maternal thyroid dysfunction, particularly severe iodine deficiency, is devastating, leading to irreversible neurologic sequelae. Moreover, mild maternal thyroid conditions, such as a mild-to-moderate iodine deficiency, may also lead to milder neurologic and behavioral conditions later during the life of the offspring. Maternal dysglycemia due to pregestational or gestational diabetes mellitus is another common situation in which fetal development encounters a hostile environment. Hyperglycemia in utero may trigger metabolic conditions in the offspring, including abnormalities of glucose tolerance and weight excess. Physicians assisting pregnant women have to be aware about these conditions, because they may go unnoticed if not properly screened. Because an early diagnosis and appropriate management may prevent most of the possible negative consequences for the progeny, the prevention, early diagnosis, and proper management of these endocrine conditions should be offered to all women undergoing pregnancy. Here, we comprehensively review the current evidence about the effects of maternal thyroid dysfunction and maternal dysglycemia on the cognitive function and carbohydrate metabolism in the offspring, two prevalent conditions of utmost importance for the child's health and development.

Hyperandrogenemia and insulin resistance: The chief culprit of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common systemic reproductive endocrine diseases, which has a variety of effects on a woman's health. Because of the involvement of multiple pathways and the lack of common clues, PCOS demonstrates multifactorial properties and heterogeneity of symptoms. Recent studies have demonstrated that the core etiology and primary endocrine characteristics of PCOS are hyperandrogenemia (HA) and insulin resistance (IR). HA and IR are the main causes of PCOS and they can interplay each other in the occurrence and development of PCOS. Just because of this, the study about the effects of HA and IR on pathophysiology of various related symptoms of PCOS is very important to understand the pathogenesis of PCOS. This paper reviews the main symptoms of PCOS, including neuroendocrine disorders, reproductive processes, dyslipidemia, obesity, hypertension, nonalcoholic fatty liver disease (NAFLD), and sleep disordered breathing, which seriously affect the physical and mental health of PCOS women. The increasing knowledge of the development pattern of HA and IR in PCOS suggests that changes in diet and lifestyle, and the discovery of potential therapeutic agents may improve PCOS. However, further studies are needed to clarify the mutual influence and relation of HA and IR in development of PCOS. This review provides an overview of the current knowledge about the effects of HA and IR on PCOS.

SUGAR-DIP trial: oral medication strategy versus insulin for diabetes in pregnancy, study protocol for a multicentre, open-label, non-inferiority, randomised controlled trial

INTRODUCTION

In women with gestational diabetes mellitus (GDM) requiring pharmacotherapy, insulin was the established first-line treatment. More recently, oral glucose lowering drugs (OGLDs) have gained popularity as a patient-friendly, less expensive and safe alternative. Monotherapy with metformin or glibenclamide (glyburide) is incorporated in several international guidelines. In women who do not reach sufficient glucose control with OGLD monotherapy, usually insulin is added, either with or without continuation of OGLDs. No reliable data from clinical trials, however, are available on the effectiveness of a treatment strategy using all three agents, metformin, glibenclamide and insulin, in a stepwise approach, compared with insulin-only therapy for improving pregnancy outcomes. In this trial, we aim to assess the clinical effectiveness, cost-effectiveness and patient experience of a stepwise combined OGLD treatment protocol, compared with conventional insulin-based therapy for GDM.

METHODS

The SUGAR-DIP trial is an open-label, multicentre randomised controlled non-inferiority trial. Participants are women with GDM who do not reach target glycaemic control with modification of diet, between 16 and 34 weeks of gestation. Participants will be randomised to either treatment with OGLDs, starting with metformin and supplemented as needed with glibenclamide, or randomised to treatment with insulin. In women who do not reach target glycaemic control with combined metformin and glibenclamide, glibenclamide will be substituted with insulin, while continuing metformin. The primary outcome will be the incidence of large-for-gestational-age infants (birth weight >90th percentile). Secondary outcome measures are maternal diabetes-related endpoints, obstetric complications, neonatal complications and cost-effectiveness analysis. Outcomes will be analysed according to the intention-to-treat principle.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of the Utrecht University Medical Centre. Approval by the boards of management for all participating hospitals will be obtained. Trial results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NTR6134; Pre-results.

Neonatal, infant, and childhood growth following metformin versus insulin treatment for gestational diabetes: A systematic review and meta-analysis

BACKGROUND

Metformin is increasingly offered as an acceptable and economic alternative to insulin for treatment of gestational diabetes mellitus (GDM) in many countries. However, the impact of maternal metformin treatment on the trajectory of fetal, infant, and childhood growth is unknown.

METHODS AND FINDINGS

PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov, and the Cochrane database were systematically searched (from database inception to 26 February 2019). Outcomes of GDM-affected pregnancies randomised to treatment with metformin versus insulin were included (randomised controlled trials and prospective randomised controlled studies) from cohorts including European, American, Asian, Australian, and African women. Studies including pregnant women with pre-existing diabetes or non-diabetic women were excluded, as were trials comparing metformin treatment with oral glucose-lowering agents other than insulin. Two reviewers independently assessed articles for eligibility and risk of bias, and conflicts were resolved by a third reviewer. Outcome measures were parameters of fetal, infant, and childhood growth, including weight, height, BMI, and body composition. In total, 28 studies (n = 3,976 participants) met eligibility criteria and were included in the meta-analysis. No studies reported fetal growth parameters; 19 studies (n = 3,723 neonates) reported measures of neonatal growth. Neonates born to metformin-treated mothers had lower birth weights (mean difference -107.7 g, 95% CI -182.3 to -32.7, I2 = 83%, p = 0.005) and lower ponderal indices (mean difference -0.13 kg/m3, 95% CI -0.26 to 0.00, I2 = 0%, p = 0.04) than neonates of insulin-treated mothers. The odds of macrosomia (odds ratio [OR] 0.59, 95% CI 0.46 to 0.77, p < 0.001) and large for gestational age (OR 0.78, 95% CI 0.62 to 0.99, p = 0.04) were lower following maternal treatment with metformin compared to insulin. There was no difference in neonatal height or incidence of small for gestational age between groups. Two studies (n = 411 infants) reported measures of infant growth (18-24 months of age). In contrast to the neonatal phase, metformin-exposed infants were significantly heavier than those in the insulin-exposed group (mean difference 440 g, 95% CI 50 to 830, I2 = 4%, p = 0.03). Three studies (n = 520 children) reported mid-childhood growth parameters (5-9 years). In mid-childhood, BMI was significantly higher (mean difference 0.78 kg/m2, 95% CI 0.23 to 1.33, I2 = 7%, p = 0.005) following metformin exposure than following insulin exposure, although the difference in absolute weights between the groups was not significantly different (p = 0.09). Limited evidence (1 study with data treated as 2 cohorts) suggested that adiposity indices (abdominal [p = 0.02] and visceral [p = 0.03] fat volumes) may be higher in children born to metformin-treated compared to insulin-treated mothers. Study limitations include heterogeneity in metformin dosing, heterogeneity in diagnostic criteria for GDM, and the scarcity of reporting of childhood outcomes.

CONCLUSIONS

Following intrauterine exposure to metformin for treatment of maternal GDM, neonates are significantly smaller than neonates whose mothers were treated with insulin during pregnancy. Despite lower average birth weight, metformin-exposed children appear to experience accelerated postnatal growth, resulting in heavier infants and higher BMI by mid-childhood compared to children whose mothers were treated with insulin. Such patterns of low birth weight and postnatal catch-up growth have been reported to be associated with adverse long-term cardio-metabolic outcomes. This suggests a need for further studies examining longitudinal perinatal and childhood outcomes following intrauterine metformin exposure. This review protocol was registered with PROSPERO under registration number CRD42018117503.

Drugs to Control Diabetes During Pregnancy

Diabetes is a common complication of pregnancy associated with both short- and long-term adverse maternal and offspring effects. All types of diabetes in pregnancy are increasing in prevalence. Treatment of diabetes in pregnancy, targeting glycemic control, improves both maternal and offspring outcomes, albeit imperfectly for many women. Pharmacologic treatment recommendations differ between pregestational and gestational diabetes. Improved treatment of diabetes in pregnancy will need to consider maternal disease heterogeneity and comorbidities as well as long-term offspring outcomes. In this review, the authors summarize recent clinical studies to highlight established pharmacologic treatments for diabetes in pregnancy and provide suggestions for further research.

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.

Intrauterine metformin exposure and offspring cardiometabolic risk factors (PedMet study): a 5-10 year follow-up of the PregMet randomised controlled trial

BACKGROUND

Metformin is increasingly used to treat gestational diabetes and type 2 diabetes in pregnancy, and in attempts to improve pregnancy outcomes in polycystic ovary syndrome and obesity. It passes across the placenta with possible long-term consequences for the offspring. We previously explored the effect of metformin, given to women with polycystic ovary syndrome during pregnancy, on children's growth up to 4 years of age. In this 5-10 year follow-up, we examined the cardiometabolic risk factors in these children.

METHODS

This is a follow-up of children from the PregMet study, a double-blind, randomised controlled trial comparing metformin with placebo in polycystic ovary syndrome pregnancies. In the PregMet study, between Feb 4, 2005, and Jan 27, 2009, 257 pregnant women aged 18-45 years with polycystic ovary syndrome according to the Rotterdam criteria were included with 274 singleton pregnancies at 5-12 weeks of gestation at 11 study centres in Norway. 17 women participated twice. Pregnant women were randomised to metformin (2000 mg/day) or placebo from inclusion in the first trimester to birth. Randomisation was stratified according to metformin use at conception. In this follow-up, the primary endpoint was body-mass index (BMI) in the offspring at 5-10 years of age assessed by the standard deviation score (Z score). The primary endpoint was analysed with independent sample t tests. ClinicalTrials.gov number NCT00159536.

FINDINGS

Of the 255 invited children from the PregMet study, 141 (55%) consented to participate and were included between April 29, 2014, and July 12, 2016. Maternal baseline characteristics in the first trimester were similar between groups. Children in the metformin group had a higher BMI Z score than those in the placebo group (difference in means=0·41, 95% CI 0·03-0·78, p=0·03).

INTERPRETATION

The increased BMI in metformin-exposed children might indicate a potential risk of inferior cardiometabolic health. Implications for adult health cannot be excluded.

FUNDING

The Research Council of Norway, Novo Nordisk Foundation, St Olavs University Hospital, and the Norwegian University of Science and Technology.

Antidiabetic medication use during pregnancy: an international utilization study

OBJECTIVE

Diabetes in pregnancy and consequently the need for treatment with antidiabetic medication (ADM) has become increasingly prevalent. The prevalence and patterns of use of ADM in pregnancy from 2006 onward in seven different countries was assessed.

RESEARCH DESIGN AND METHODS

Data sources included individually linked data from the nationwide health registers in Denmark (2006-2016), Finland (2006-2016), Iceland (2006-2012), Norway (2006-2015), Sweden (2006-2015), state-wide administrative and claims data for New South Wales, Australia (2006-2012) and two US insurance databases: Medicaid Analytic eXtract (MAX; 2006-2012, public) and IBM MarketScan (2012-2015, private). The prevalence of ADM use was calculated as the proportion of pregnancies with at least one filled prescription of an ADM in the 90 days before pregnancy or within the three trimesters of pregnancy.

RESULTS

Prevalence of any ADM use in 5 279 231 pregnancies was 3% (n=147 999) and varied from under 2% (Denmark, Norway, and Sweden) to above 5% (Australia and US). Insulin was the most used ADM, and metformin was the most used oral hypoglycemic agent with increasing use over time in all countries. In 11.4%-62.5% of pregnancies with prepregnancy use, ADM (primarily metformin) was discontinued. When ADM treatment was initiated in late pregnancy for treatment of gestational diabetes mellitus, insulin was most often dispensed, except in the US, where glibenclamide was most often used.

CONCLUSIONS

Prevalence and patterns of use of ADM classes varied between countries and over time. While insulin remained the most common ADM used in pregnancy, metformin use increased significantly over the study period.