Prevention of gestational diabetes by metformin plus diet in patients with polycystic ovary syndrome

Management of type 2 diabetes in pregnancy: a narrative review

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

The Effect of Metformin and Carbohydrate-Controlled Diet on DNA Methylation and Gene Expression in the Endometrium of Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is an endocrine disease associated with infertility and metabolic disorders in reproductive-aged women. In this study, we evaluated the expression of eight genes related to endometrial function and their DNA methylation levels in the endometrium of PCOS patients and women without the disease (control group). In addition, eight of the PCOS patients underwent intervention with metformin (1500 mg/day) and a carbohydrate-controlled diet (type and quantity) for three months. Clinical and metabolic parameters were determined, and RT-qPCR and MeDIP-qPCR were used to evaluate gene expression and DNA methylation levels, respectively. Decreased expression levels of HOXA10, GAB1, and SLC2A4 genes and increased DNA methylation levels of the HOXA10 promoter were found in the endometrium of PCOS patients compared to controls. After metformin and nutritional intervention, some metabolic and clinical variables improved in PCOS patients. This intervention was associated with increased expression of HOXA10, ESR1, GAB1, and SLC2A4 genes and reduced DNA methylation levels of the HOXA10 promoter in the endometrium of PCOS women. Our preliminary findings suggest that metformin and a carbohydrate-controlled diet improve endometrial function in PCOS patients, partly by modulating DNA methylation of the HOXA10 gene promoter and the expression of genes implicated in endometrial receptivity and insulin signaling.

Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes

BACKGROUND

Gestational diabetes with onset or first recognition during pregnancy is an increasing problem worldwide. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. Myo-inositol is one of the intracellular mediators of the insulin signal and correlates with insulin sensitivity in type 2 diabetes. The potential beneficial effect of improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes. This is an update of a review first published in 2015.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO ICTRP (17 March 2022) and the reference lists of retrieved studies.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) including cluster-RCTs and conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes in pregnant women. We included studies that compared any dose of myo-inositol, alone or in a combination preparation, with no treatment, placebo or another intervention. Quasi-randomised and cross-over trials were not eligible. We excluded women with pre-existing type 1 or type 2 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, assessed risk of bias and extracted the data. We checked the data for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included seven RCTs (one conducted in Ireland, six conducted in Italy) reporting on 1319 women who were 10 weeks to 24 weeks pregnant at the start of the studies. The studies had relatively small sample sizes and the overall risk of bias was low. For the primary maternal outcomes, meta-analysis showed that myo-inositol may reduce the incidence of gestational diabetes (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.31 to 0.90; 6 studies, 1140 women) and hypertensive disorders of pregnancy (RR 0.34, 95% CI 0.19 to 0.61; 5 studies, 1052 women). However, the certainty of the evidence was low to very low. For the primary neonatal outcomes, only one study measured the risk of a large-for-gestational-age infant and found myo-inositol was associated with both appreciable benefit and harm (RR 1.40, 95% CI 0.65 to 3.02; 1 study, 234 infants; low-certainty evidence). None of the included studies reported on the other primary neonatal outcomes (perinatal mortality, mortality or morbidity composite). For the secondary maternal outcomes, we are unclear about the effect of myo-inositol on weight gain during pregnancy (mean difference (MD) -0.25 kilogram (kg), 95% CI -1.26 to 0.75 kg; 4 studies, 831 women) and perineal trauma (RR 4.0, 95% CI 0.45 to 35.25; 1 study, 234 women) because the evidence was assessed as being very low-certainty. Further, myo-inositol may result in little to no difference in caesarean section (RR 0.91, 95% CI 0.77 to 1.07; 4 studies, 829 women; low-certainty evidence). None of the included studies reported on the other secondary maternal outcomes (postnatal depression and the development of subsequent type 2 diabetes mellitus). For the secondary neonatal outcomes, meta-analysis showed no neonatal hypoglycaemia (RR 3.07, 95% CI 0.90 to 10.52; 4 studies; 671 infants; very low-certainty evidence). However, myo-inositol may be associated with a reduction in the incidence of preterm birth (RR 0.35, 95% CI 0.17 to 0.70; 4 studies; 829 infants). There were insufficient data for a number of maternal and neonatal secondary outcomes, and no data were reported for any of the long-term childhood or adulthood outcomes, or for health service utilisation outcomes.

AUTHORS' CONCLUSIONS

Evidence from seven studies shows that antenatal dietary supplementation with myo-inositol during pregnancy may reduce the incidence of gestational diabetes, hypertensive disorders of pregnancy and preterm birth. Limited data suggest that supplementation with myo-inositol may not reduce the risk of a large-for-gestational-age infant.  The current evidence is based on small studies that were not powered to detect differences in outcomes such as perinatal mortality and serious infant morbidity. Six of the included studies were conducted in Italy and one in Ireland, which raises concerns about the lack of generalisability to other settings. There is evidence of inconsistency among doses of myo-inositol, the timing of administration and study population. As a result, we downgraded the certainty of the evidence for many outcomes to low or very low certainty. Further studies for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors. Myo-inositol at different doses, frequency and timing of administration, should be compared with placebo, diet and exercise, and pharmacological interventions. Long-term follow-up should be considered and outcomes should include potential harms, including adverse effects.

Efficacy and safety of metformin in pregnant women with polycystic ovary syndrome: a systematic review with meta-analysis of randomized and non-randomized controlled trials

OBJECTIVE

To evaluate the efficacy and safety of using metformin in pregnant women with polycystic ovarian syndrome (PCOS) and to explore the most effective and safe protocol by using a meta-analysis method.

METHODS

Medline, EMBASE, Cochrane Library, and other databases were searched for randomized controlled trials and prospective cohort studies enrolling pregnant women with PCOS on receiving metformin or placebo or nothing. Subgroup analyses were undertaken.

RESULTS

A total of 17 studies involving 2899 patients were included. Compared with control group, the use of metformin significantly reduced the incidence of preterm delivery (cumulative rate 3.86% vs 9.19%, relative risk (RR), 0.42 [95% confidence interval (CI), 0.25-0.71,]; p = .001), early miscarriage (cumulative rate 6.58% vs 18.35%, RR, 0.40 [95% CI, 0.20-0.78]; p = .007), gestational diabetes (cumulative rate 12.86% vs 22.91%, RR, 0.48 [95% CI, 0.26-0.89]; p = .02), and pre-eclampsia (cumulative rate 4.95% vs 7.72%, RR, 0.61 [95% CI, 0.40-0.93]; p = .02), the need for insulin treatment throughout pregnancy (cumulative rate 2.14% vs 5.12%, RR, 0.43 [95% CI, 0.22-0.85]; p = .01), and weight gain of pregnant women (mean difference, -2.45, [95% CI, -3.04 to -1.85]; p < .00001).

CONCLUSIONS

The use of metformin in pregnant women with PCOS can significantly reduce maternal complications. No significant difference was observed in serious maternal adverse events. The efficacy and safety of metformin are worthy of recognition.

Effects of Low-Dose Spironolactone Combined with Metformin or Either Drug Alone on Insulin Resistance in Patients with Polycystic Ovary Syndrome: A Pilot Study

Metformin and spironolactone alone can be used for the management of polycystic ovarian syndrome (PCOS), and their combination could result in even better outcomes. To compare the effects and safety of low-dose spironolactone combined with metformin or either drug alone on insulin resistance (IR) and functional improvement in patients with PCOS, this was a single-center, randomized, open-label, pilot study of patients with PCOS at the Third Affiliated Hospital of Guangzhou Medical University between 01/2014 and 01/2016. The participants were randomized 1 : 1 : 1 to metformin, spironolactone, or metformin + spironolactone. The primary endpoint was the change in the homeostatic model assessment (HOMA)-IR after 12 weeks of treatment. A total of 189 participants were randomized (63 per group); 31 dropped out, and 54, 51, and 53 completed the 12-week treatment in the metformin, spironolactone, and combined groups, respectively. There were no differences in any parameters between the metformin and spironolactone groups (all P > 0.05). In the combined group, after 12 weeks of treatment, HOMA-IR (1.71 ± 0.91) was lower than in the metformin (1.92 ± 1.07, P < 0.05) and spironolactone (2.38 ± 1.14, P < 0.05) groups. In addition, total testosterone (TT), free androgen index (FAI), and area under the curve-insulin (AUCins) were lower in the combined group compared with the metformin group (all P < 0.05), while TT, FAI, HOMA-β, fasting plasma glucose, and AUCins were lower in the spironolactone group (all P < 0.05). Both metformin and spironolactone decreased HOMA-IR in patients with PCOS but without differences between the two monotherapies. The combined therapy decreased HOMA-IR to a greater extent than monotherapy.

Inositols: From Established Knowledge to Novel Approaches

Myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) are natural compounds involved in many biological pathways. Since the discovery of their involvement in endocrine signal transduction, myo-Ins and D-chiro-Ins supplementation has contributed to clinical approaches in ameliorating many gynecological and endocrinological diseases. Currently both myo-Ins and D-chiro-Ins are well-tolerated, effective alternative candidates to the classical insulin sensitizers, and are useful treatments in preventing and treating metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS), gestational diabetes mellitus (GDM), and male fertility disturbances, like sperm abnormalities. Moreover, besides metabolic activity, myo-Ins and D-chiro-Ins deeply influence steroidogenesis, regulating the pools of androgens and estrogens, likely in opposite ways. Given the complexity of inositol-related mechanisms of action, many of their beneficial effects are still under scrutiny. Therefore, continuing research aims to discover new emerging roles and mechanisms that can allow clinicians to tailor inositol therapy and to use it in other medical areas, hitherto unexplored. The present paper outlines the established evidence on inositols and updates on recent research, namely concerning D-chiro-Ins involvement into steroidogenesis. In particular, D-chiro-Ins mediates insulin-induced testosterone biosynthesis from ovarian thecal cells and directly affects synthesis of estrogens by modulating the expression of the aromatase enzyme. Ovaries, as well as other organs and tissues, are characterized by a specific ratio of myo-Ins to D-chiro-Ins, which ensures their healthy state and proper functionality. Altered inositol ratios may account for pathological conditions, causing an imbalance in sex hormones. Such situations usually occur in association with medical conditions, such as PCOS, or as a consequence of some pharmacological treatments. Based on the physiological role of inositols and the pathological implications of altered myo-Ins to D-chiro-Ins ratios, inositol therapy may be designed with two different aims: (1) restoring the inositol physiological ratio; (2) altering the ratio in a controlled way to achieve specific effects.

An update on the use of inositols in preventing gestational diabetes mellitus (GDM) and neural tube defects (NTDs)

INTRODUCTION

Obstetric history and maternal body composition and lifestyle may be associated with serious complications both for the mother, such as gestational diabetes mellitus (GDM), and for the fetus, including congenital malformations such as neural tube defects (NTDs).

AREAS COVERED

In view of the recent knowledge, changes in nutritional and physical activity habits ameliorate glycemic control during pregnancy and in turn improve maternal and neonatal health outcomes. Recently, a series of small clinical and experimental studies indicated that supplemenation with inositols, a family of insulin sensitizers, was associated with beneficial impact for both GDM and NTDs.

EXPERT OPINION

Herein, we discuss the most significant scientific evidence supporting myo-inositol administration as a prophylaxis for the above-mentioned conditions.

Can maternal treatment with metformin during gestation and lactation cause metabolic and cardiovascular disorders in rat offspring?

Objective: The aim was to evaluate if maternal treatment with metformin (MET) during pregnancy and lactation could be safe for metabolic and cardiovascular parameters of adult male and female offspring.Materials and methods: Wistar female rats were treated with MET (293 mg/kg/d) or tap water, by gavage during gestation (METG or CTRG) or gestation and lactation (METGL or CTRGL).Results: At 75 days of life, male and female MET offspring presented similar blood pressure when compared with their CTR. The heart rate of female METGL was higher than in the CTRGL. The insulin sensitivity, basal glycaemia, body weight, Lee index of obesity, plasmatic concentration of triglycerides, total cholesterol and fat acid of male and female MET were similar to CTR groups. Lower fat pad deposition was observed in female METG and METGL.Conclusion: MET exposure during gestational and lactation does not program cardiovascular and metabolic alterations in adult offspring life.

Metformin in pregnancy to avert gestational diabetes in women at high risk: Meta-analysis of randomized controlled trials

Previous randomized and observational studies on the efficacy of metformin in pregnancy to reduce incident gestational diabetes mellitus (GDM) in women at high risk (obesity, polycystic ovary syndrome [PCOS], or pregestational insulin resistance) have been conflicting and several groups are planning further randomized controlled trials (RCTs) to answer this question conclusively. This work assesses the efficacy of metformin in pregnancy to avert one outcome-incident GDM in women at high risk. We included RCTs comparing metformin with usual care or placebo controls in terms of incident GDM and recruiting women at high risk during early pregnancy. Eleven eligible trials enrolled 2370 adult women whose intervention arm consisted of metformin started at conception or before 20 weeks of gestation. Risk of GDM was similar in intervention compared with controls (risk ratio [RR] 1.03; 95% confidence interval [CI], 0.85-1.24). The data were of sufficient quality meeting the criteria for consistency and directness. We conclude that metformin does not contribute to averting the GDM outcome in women at high risk when initiated in pregnancy. The evidence provided by this synthesis affirms that further broad clinical trials investigating this question are no longer needed.

Do raised two-hour pre-pregnancy insulin levels confer the same risks of developing GDM, as raised fasting levels, in recurrent miscarriage patients?

This study questioned whether raised pre-pregnancy two-hour (2 h) insulin levels, measured in recurrent embryonic miscarriage (RM) patients via a 75 g Oral Glucose Tolerance Test (OGTT), are associated with an increased risk of gestational diabetes mellitus (GDM) in a subsequent pregnancy. Patients had a 75 g OGTT and insulin levels evaluated (n = 170). 54.1% had normal glucose and insulin levels, 45.9% had levels indicating hyperinsulinism (HI). In the 98 patients who achieved a pregnancy, the prevalence of GDM was 3.7% in those without HI, and 35.7% in the patients who only had raised 2 h insulin levels. While HI has been described as a risk factor for miscarriages only in relation to raised fasting (basal) insulin levels, this study demonstrated that raised 2 h insulin levels predict an increased risk of GDM in a subsequent pregnancy. Thus raised 2 h insulin levels likely confer a similar risk to raised fasting insulin levels in RM patients.Impact statementWhat is already known on this subject? Fasting hyperinsulinism is known to be associated with an increased risk of gestational diabetes mellitus (GDM) in pregnancy. Hyperinsulinism, as reflected by the fasting (basal) insulin levels >20mU/L, has been recognized as a risk factor for recurrent miscarriages, particularly in patients with polycystic ovarian syndrome (PCOS), in the World literature. Raised two-hour insulin levels have not been considered as a risk factor in the literature before.What do the results of the study add? We have demonstrated a 10-fold increase in the development of GDM in patients with fasting insulin resistance, and/or raised 2h insulin levels, and an almost 10-fold increase in patients with only raised 2h levels. 58.8% of the patients who subsequently developed GDM only had raised 2h levels and would have been missed with routine testing.What are the implications of these findings for clinical practice and/or further research? Our study has demonstrated that GDM was three times more prevalent in the patients with only raised 2h levels, than in those only with raised fasting levels, reflecting insulin resistance/hyperinsulinism. Insulin studies including 2h insulin levels are therefore an important factor to consider when working up these patients. Insulin studies pre-pregnancy may be useful in identifying women at risk of suffering miscarriages or of developing GDM in a subsequent pregnancy.

Naturally Occurring and Experimentally Induced Rhesus Macaque Models for Polycystic Ovary Syndrome: Translational Gateways to Clinical Application

Indian rhesus macaque nonhuman primate models for polycystic ovary syndrome (PCOS) implicate both female hyperandrogenism and developmental molecular origins as core components of PCOS etiopathogenesis. Establishing and exploiting macaque models for translational impact into the clinic, however, has required multi-year, integrated basic-clinical science collaborations. Paradigm shifting insight has accrued from such concerted investment, leading to novel mechanistic understanding of PCOS, including hyperandrogenic fetal and peripubertal origins, epigenetic programming, altered neural function, defective oocytes and embryos, adipogenic constraint enhancing progression to insulin resistance, pancreatic decompensation and type 2 diabetes, together with placental compromise, all contributing to transgenerational transmission of traits likely to manifest in adult PCOS phenotypes. Our recent demonstration of PCOS-related traits in naturally hyperandrogenic (High T) female macaques additionally creates opportunities to employ whole genome sequencing to enable exploration of gene variants within human PCOS candidate genes contributing to PCOS-related traits in macaque models. This review will therefore consider Indian macaque model contributions to various aspects of PCOS-related pathophysiology, as well as the benefits of using macaque models with compellingly close homologies to the human genome, phenotype, development and aging.

Gestational diabetes mellitus

Hyperglycaemia that develops during pregnancy and resolves after birth has been recognized for over 50 years, but uniform worldwide consensus is lacking about threshold hyperglycaemic levels that merit a diagnosis of 'gestational diabetes mellitus' (GDM) and thus treatment during pregnancy. GDM is currently the most common medical complication of pregnancy, and prevalence of undiagnosed hyperglycaemia and even overt diabetes in young women is increasing. Maternal overweight and obesity, later age at childbearing, previous history of GDM, family history of type 2 diabetes mellitus and ethnicity are major GDM risk factors. Diagnosis is usually performed using an oral glucose tolerance test (OGTT), although a non-fasting, glucose challenge test (GCT) is used in some parts of the world to screen women for those requiring a full OGTT. Dietary modification and increased physical activity are the primary treatments for GDM, but pharmacotherapy, usually insulin, is used when normoglycaemia is not achieved. Oral hypoglycaemic agents, principally metformin and glibenclamide (glyburide), are also used in some countries. Treatment improves immediate pregnancy outcomes, reducing excess fetal growth and adiposity and pregnancy-related hypertensive disorders. GDM increases the risk of long-term complications, including obesity, impaired glucose metabolism and cardiovascular disease, in both the mother and infant. Optimal management of mother and infant during long-term follow-up remains challenging, with very limited implementation of preventive strategies in most parts of the world.

Hyperandrogenic origins of polycystic ovary syndrome - implications for pathophysiology and therapy

INTRODUCTION

Polycystic ovary syndrome (PCOS) diagnosis comprises combinations of female hyperandrogenism, menstrual irregularity and polycystic ovaries. While it is a familial and highly prevalent endocrine disorder, progress towards a cure is hindered by absence of a definitive pathogenic mechanism and lack of an animal model of naturally occurring PCOS.

AREAS COVERED

These include an overview of PCOS and its potential etiology, and an examination of insights gained into its pathogenic origins. Animal models derived from experimentally-induced hyperandrogenism during gestation, or from naturally-occurring PCOS-like traits, most reliably demonstrate reproductive, neuroendocrine and metabolic pathogenesis.

EXPERT OPINION

Genetic studies, while identifying at least 17 PCOS risk genes, account for <10% of women with PCOS. A number of PCOS risk genes involve regulation of gonadotropin secretion or action, suggesting a reproductive neuroendocrine basis for PCOS pathogenesis. Consistent with this notion, a number of animal models employing fetal androgen excess demonstrate epigenetic induction of PCOS-like traits, including reproductive neuroendocrine and metabolic dysfunction. Monkey models are most comprehensive, while mouse models provide molecular insight, including identifying the androgen receptor, particularly in neurons, as mediating androgen-induced PCOS-like programming. Naturally-occurring female hyperandrogenism is also demonstrated in monkeys. Animal models are poised to delineate molecular gateways to PCOS pathogenesis.

Metformin therapy before conception versus throughout the pregnancy and risk of gestational diabetes mellitus in women with polycystic ovary syndrome: a systemic review, meta-analysis and meta-regression

The results of studies that assessed the impact of metformin treatments on gestational diabetes mellitus (GDM) in patients with polycystic ovary syndrome (PCOS) are inconclusive. In addition, the impact of time and duration of metformin therapy for an optimum reduction of GDM has not been reported in these studies. This study aimed to summarize current knowledge regarding the effect of metformin-therapy before conception versus throughout pregnancy on the risk of GDM in women with PCOS. PubMed, Scopus, Google Scholar and ScienceDirect databases were searched to identify relevant studies. Both fixed and random effect models were used. Subgroup analyses were performed based on the on the study methodology. The association between the PCOS status and GDM was assessed using the univariate and multiple meta-regression analysis adjusted by the BMI and metformin therapy. Forty-eight of 1397 identified studies were included involving 5711 PCOS patients and 20,296 controls. Regardless of metformin therapy, the prevalence of GDM diagnosed in the second trimester among women with PCOS was significantly higher than healthy controls that was independent of obesity. Including all studies, the increased risk of GDM among women with PCOS, compared to healthy controls, disappeared after the adjustment of metformin-therapy (β = 0.08, 95% CI 0.04, 0.2; p = 0.624). By excluding observational studies as a source of bias, the prevalence of GDM among women with PCOS treated using metformin before conception till the end of pregnancy did not differ from treated just before conception (β = - 0.09, 95% CI - 0.2, 0.02; p = 0.092) or those without metformin therapy (β = - 0.05, 95% CI - 0.07, 0.04; p = 0.301). The results remained unchanged after the subgroup analysis based on the methodology of RCTs and non-RCTs studies. The main body of literature in the current meta-analysis was observational, which may be mixed with some sources of bias. Also, a lack of well-designed and high quality interventional studies means that the findings should be interpreted with cautious. In this respect, decisions regarding the continuation or discontinuation of metformin therapy in women with PCOS are somewhat arbitrary and can be made individually based on the patient's condition given the presence or absence of other GDM risk factors. Additional well-designed RCTs still need for precise recommendation.

Metformin as a prophylactic treatment of gestational diabetes in pregnant patients with pregestational insulin resistance: A randomized study

AIM

We aimed to assess the use of metformin (MTF) in the prevention of gestational diabetes mellitus (GDM) in patients with pregestational insulin resistance (PIR).

METHODS

A double blind, multicenter, randomized trial was carried out in patients with a history of PIR and pregestational MTF treatment. Groups were allocated either to MTF 1700 mg/day or placebo. Patients were recruited between 12⁺⁰ and 15⁺⁶  gestational weeks, and treatment was extended until week 36. A multiple logistic regression analysis was applied to determine the relation between the use of metformin and the development of GDM.

RESULTS

One hundred and forty one patients were randomized (68 patients in the MTF group and 73 in the placebo group). A total of 30 patients withdrew from the study during follow-up. Administration of MTF was not associated with a decrease in the incidence of GDM as compared to placebo (37.5% vs 25.4%, respectively; P = 0.2). Moreover, MTF administration was associated with a significant increase in drug intolerance as compared to placebo (14.3% vs 1.8%, respectively; P = 0.02).

CONCLUSION

The use of MTF is not effective in prevention of GDM in populations with PIR. The use of MTF shows a significantly higher frequency of drug intolerance than placebo.

Windows of Opportunity for Lifestyle Interventions to Prevent Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is linked with several acute maternal health risks and long-term development of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM similarly increases offspring risk of early-life health complications and later disease. GDM recurrence is common, affecting 40 to 73% of women, and augments associated maternal/fetal/child health risks. Modifiable and independent risk factors for GDM include maternal excessive gestational weight gain and prepregnancy overweight and obesity. Lifestyle interventions that target diet, activity, and behavioral strategies can effectively modify body weight. Randomized clinical trials testing the effects of lifestyle interventions during pregnancy to reduce excessive gestational weight gain have generally shown mixed effects on reducing GDM incidence. Trials testing the effects of postpartum lifestyle interventions among women with a history of GDM have shown reduced incidence of diabetes and improved cardiovascular disease risk factors. However, the long-term effects of interpregnancy or prepregnancy lifestyle interventions on subsequent GDM remain unknown. Future adequately powered and well-controlled clinical trials are needed to determine the effects of lifestyle interventions to prevent GDM and identify pathways to effectively reach reproductive-aged women across all levels of society, before, during, and after pregnancy.

Myo-Inositol Supplementation to Prevent Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common complication characterized by increased insulin resistance, and by increased risk for adverse pregnancy outcomes affecting both the mother and the fetus. International guidelines describe optimal ways to recognize it, and the recommended treatment of patients affected to reduce adverse outcomes. Improving insulin resistance could reduce incidence of GDM and its complications. Recently, a few trials have been published on the possible prevention of GDM. Inositol has been proposed as a food supplement that might reduce gestational diabetes incidence in high-risk pregnant women.

Antenatal dietary supplementation with myo-inositol in women during pregnancy for preventing gestational diabetes

BACKGROUND

Gestational diabetes, glucose intolerance with onset or first recognition during pregnancy, is a rising problem worldwide. Both non-pharmacological and pharmacological approaches to the prevention of gestational diabetes have been, and continue to be explored. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. It is one of the intracellular mediators of the insulin signal and correlated with insulin sensitivity in type 2 diabetes. The potential beneficial effect on improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes.

OBJECTIVES

To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, WHO ICTRP (2 November 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

We sought published and unpublished randomised controlled trials, including conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes mellitus (GDM). Quasi-randomised and cross-over trials were not eligible for inclusion, but cluster designs were eligible. Participants in the trials were pregnant women. Women with pre-existing type 1 or type 2 diabetes were excluded. Trials that compared the administration of any dose of myo-inositol, alone or in a combination preparation were eligible for inclusion. Trials that used no treatment, placebo or another intervention as the comparator were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, risk of bias and extracted the data. Data were checked for accuracy.

MAIN RESULTS

We included four randomised controlled trials (all conducted in Italy) reporting on 567 women who were less than 11 weeks' to 24 weeks' pregnant at the start of the trials. The trials had small sample sizes and one trial only reported an interim analysis. Two trials were open-label. The overall risk of bias was unclear.For the mother, supplementation with myo-inositol was associated with a reduction in the incidence of gestational diabetes compared with control (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.29 to 0.64; three trials; n = 502 women). Using GRADE methods this evidence was assessed as low with downgrading due to unclear risk of bias for allocation concealment in two of the included trials and lack of generalisability of findings. For women who received myo-inositol supplementation, the incidence of GDM ranged from 8% to 18%; for women in the control group, the incidence of GDM was 28%, using International Association of Diabetes and Pregnancy Study Groups Consensus Panel 2010 criteria to diagnose GDM.Two trials reported on hypertensive disorders of pregnancy, a primary maternal outcome of this review. There was no clear difference in risk of hypertensive disorders of pregnancy between the myo-inositol and control groups (average RR 0.43, 95% CI 0.02 to 8.41; two trials; n = 398 women; Tau(2) = 3.23; I(2) = 69%). Using GRADE methods, this evidence was assessed as very low, with downgrading due to wide confidence intervals with very low event rates, a small sample size, and lack of blinding and unclear allocation concealment methods, and a lack of generalisability. For women who received myo-inositol the risk of hypertensive disorders of pregnancy ranged from 0% to 33%; for women in the control group the risk was 4%.For the infant, none of the included trials reported on the primary neonatal outcomes of this systematic review (large-for-gestational age, perinatal mortality, mortality or morbidity composite).In terms of this review's secondary outcomes, there was no clear difference in the risk of caesarean section between the myo-inositol and control groups (RR 0.95, 95% CI 0.76 to 1.19; two trials; n = 398 women). Using GRADE methods, this evidence was assessed as low, with downgrading due to unclear risk of bias in one trial and lack of generalisability. For women who received myo-inositol supplementation, the risk of having a caesarean section ranged from 34% to 54%; for women in the control group the was 45%. There were no maternal adverse effects of therapy in the two trials that reported on this outcome (the other two trials did not report this outcome).Two trials found no clear difference in the risk of macrosomia between infants whose mothers received myo-inositol supplementation compared with controls (average RR 0.35, 95% CI 0.02 to 6.37; two trials; n = 398 infants;Tau(2) = 3.33; I(2) = 73%). Similarly, there was no clear difference between groups in terms of neonatal hypoglycaemia (RR 0.36, 95% CI 0.01 to 8.66) or shoulder dystocia (average RR 2.33, 95% CI 0.12 to 44.30, Tau(2) = 3.24; I(2) = 72%).There was a lack of data available for a large number of maternal and neonatal secondary outcomes, and no data for any of the long-term childhood or adulthood outcomes, or for health service cost outcomes.

AUTHORS' CONCLUSIONS

Evidence from four trials of antenatal dietary supplementation with myo-inositol during pregnancy shows a potential benefit for reducing the incidence of gestational diabetes. No data were reported for any of this review's primary neonatal outcomes. There were very little outcome data for the majority of this review's secondary outcomes. There is no clear evidence of a difference for macrosomia when compared with control.The current evidence is based on small trials that are not powered to detect differences in outcomes including perinatal mortality and serious infant morbidity. All of the included studies were conducted in Italy which raises concerns about the lack of generalisability of the evidence to other settings. There is evidence of inconsistency and indirectness and as a result, many of the judgements on the quality of the evidence were downgraded to low or very low quality (GRADEpro Guideline Development Tool).Further trials for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors and use of myo-inositol (different doses, frequency and timing of administration) in comparison with placebo, diet and exercise or pharmacological interventions. Outcomes should include potential harms including adverse effects.

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

BACKGROUND

Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects.

METHODS

Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate.

RESULTS

Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of their pregnancy. Regarding type 2 diabetic women, we did not identify a sufficient number of studies with metformin exposure during the first trimester to proceed with the meta-analysis.

CONCLUSIONS

There is currently no evidence that metformin is associated with an increased risk of major birth defects in women affected by PCOS and treated during the first trimester. However larger ad hoc studies are warranted in order to definitely confirm the safety and efficacy of this drug in pregnancy.

Effect of metformin intervention during pregnancy on the gestational diabetes mellitus in women with polycystic ovary syndrome: a systematic review and meta-analysis

Metformin is an effective insulin sensitizer treating type 2 diabetes mellitus. However, the functional consequences of metformin administration throughout pregnancy on gestational diabetes mellitus (GDM) with polycystic ovary syndrome (PCOS) have not been assessed. We therefore performed a meta-analysis and system review to determine the effect of metformin on GDM in PCOS. A meta-analysis was performed on the published studies before December, 2013. Meta-analysis examined whether metformin could reduce GDM occurrence in PCOS with a fixed effect model. The odds ratio (OR) with 95% confidence interval (95% CI) was calculated to estimate the strength of association. A total of 13 studies including 5 RCTs and 8 non-RCTs were enrolled. Ultimately, effectiveness analysis demonstrated that, in total, there was no significant availability of metformin on GDM in PCOS in contrast to placebo (OR = 1.07, 95% CI 0.60-1.92) in RCTs and significant availability of metformin on GDM (OR = 0.19, 95% CI 0.13-0.27) was indicated in non-RCTs. In summary, according to the results of our meta-analysis, strictly, metformin did not significantly effect on GDM with PCOS, though more multicenters RCTs still need to be investigated.

[Polycystic ovary syndrome: what are the obstetrical risks?]

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and the leading cause of female infertility. This condition is frequently associated with significant metabolic disorders, including obesity and hyperinsulinemia. Therefore, it seems essential to focus on the pregnancy of these patients and possible obstetric complications. Many studies suggest an increase in the risk of obstetric pathology: early miscarriage, gestational hypertension, preeclampsia, gestational diabetes mellitus diagnosed during early pregnancy, prematurity, low birthweight or macrosomia, neonatal complications and cesarean sections. However, it is difficult to conclude clearly about it, because of the heterogeneity of definition of PCOS in different studies. In addition, many confounding factors inherent in PCOS including obesity are not always taken into account and generate a problem of interpretation. However it seems possible to conclude that PCOS does not increase the risk of placental abruption, HELLP syndrome, liver disease, postpartum hemorrhage, late miscarriage and stillbirth.

Lack of metformin effect on mouse embryo AMPK activity: implications for metformin treatment during pregnancy

BACKGROUND

Adenosine monophosphate-activated protein kinase (AMPK) is stimulated in embryos during diabetic pregnancy by maternal hyperglycaemia-induced embryo oxidative stress. Stimulation of AMPK disrupts embryo gene expression and causes neural tube defects. Metformin, which may be taken during early pregnancy, has been reported to stimulate AMPK activity. Thus, the benefits of improved glycaemic control could be offset by stimulated embryo AMPK activity. Here, we investigated whether metformin can stimulate AMPK activity in mouse embryos and can adversely affect embryo gene expression and neural tube defects.

METHODS

Pregnant nondiabetic mice were administered metformin beginning on the first day of pregnancy. Activation of maternal and embryo AMPK [phospho-AMPK α (Thr172) relative to total AMPK], expression of Pax3, a gene required for neural tube closure, and neural tube defects were studied. Mouse embryonic stem cells were used as a cell culture model of embryonic neuroepithelium to study metformin effects on AMPK and Pax3 expression.

RESULTS

Metformin had no effect on AMPK in embryos or maternal skeletal muscle but increased activated AMPK in maternal liver. Metformin did not inhibit Pax3 expression or increase neural tube defects. However, metformin increased activated AMPK and inhibited Pax3 expression by mouse embryonic stem cells. Mate1/Slc47a1 and Oct3/Slc22a, which encode metformin transporters, were expressed at barely detectable levels by embryos.

CONCLUSIONS

Although metformin can have effects associated with diabetic embryopathy in vitro, the lack of effects on mouse embryos in vivo may be due to lack of metformin transporters and indicates that the benefits of metformin on glycaemic control are not counteracted by stimulation of embryo AMPK activity and consequent embryopathy.

Efficacy and safety of metformin during pregnancy in women with gestational diabetes mellitus or polycystic ovary syndrome: a systematic review

BACKGROUND

Metformin is an effective oral anti-hyperglycemic agent that is widely used to manage diabetes mellitus type 2 in the general population and more recently, in pregnancy. However, as metformin crosses the placenta, its use during pregnancy raises concerns regarding potential adverse effects on the mother and fetus.

OBJECTIVE

(i) To provide background for the use of metformin during pregnancy through a narrative review and (ii) to critically appraise the published evidence on the efficacy and safety of using metformin during pregnancy through a systematic review.

RESULTS

Metformin appears to be effective and safe for the treatment of gestational diabetes mellitus (GDM), particularly for overweight or obese women. However, patients with multiple risk factors for insulin resistance may not meet their treatment goals with metformin alone and may require supplementary insulin. Evidence suggests that there are potential advantages for the use of metformin over insulin in GDM with respect to maternal weight gain and neonatal outcomes. Furthermore, patients are more accepting of metformin than insulin. The use of metformin throughout pregnancy in women with polycystic ovary syndrome reduces the rates of early pregnancy loss and preterm labor and protects against fetal growth restriction. There have been no demonstrable teratogenic effects, intra-uterine deaths or developmental delays with the use of metformin.

CONCLUSIONS

The publications reviewed in this paper support the efficacy and safety of metformin during pregnancy with respect to immediate pregnancy outcomes. Because there are no guidelines for the continuous use of metformin in pregnancy, the duration of treatment is based on clinical judgment and experience on a case-by-case basis.

How metformin acts in PCOS pregnant women: insights into insulin secretion and peripheral action at each trimester of gestation

OBJECTIVE

Metformin has been reported to reduce the risk of gestational diabetes (GD) in women with polycystic ovarian syndrome (PCOS). However, little is known about the mechanisms of action of this drug during pregnancy. In the attempt to fill this gap, we performed a prospective longitudinal study providing a detailed examination of glucose and insulin metabolism in pregnant women with PCOS undergoing metformin therapy.

RESEARCH DESIGN AND METHODS

We enrolled 60 women with PCOS who conceived while undergoing metformin treatment. An oral glucose tolerance test and a euglycemic-hyperinsulinemic clamp were performed at each trimester of gestation in 47 ongoing pregnancies.

RESULTS

Twenty-two of the study subjects had development of GD despite the treatment. At baseline, insulin sensitivity was comparable between women who had development of GD and women who did not. A progressive decline in this parameter occurred in all subjects, independently of the trimester of GD diagnosis. Insulin secretion was significantly higher during the first trimester in patients with an early failure of metformin treatment. Women with third trimester GD and women with no GD exhibited a significant increase in insulin output as gestation proceeded. All newborns were healthy and only one case of macrosomia was observed.

CONCLUSIONS

Women with PCOS who enter pregnancy in a condition of severe hyperinsulinemia have development of GD earlier, independently of metformin treatment. The physiologic deterioration of insulin sensitivity is not affected by the drug and does not predict the timing and severity of the glycemic imbalance. Despite the high incidence of GD observed, the drug itself or the intensive monitoring probably accounted for the good neonatal outcome.

myo-Inositol supplementation and onset of gestational diabetes mellitus in pregnant women with a family history of type 2 diabetes: a prospective, randomized, placebo-controlled study

OBJECTIVE

To check the hypothesis that myo-inositol supplementation may reduce gestational diabetes mellitus (GDM) onset in pregnant women with a family history of type 2 diabetes.

RESEARCH DESIGN AND METHODS

A 2-year, prospective, randomized, open-label, placebo-controlled study was carried out in pregnant outpatients with a parent with type 2 diabetes who were treated from the end of the first trimester with 2 g myo-inositol plus 200 µg folic acid twice a day (n = 110) and in the placebo group (n = 110), who were only treated with 200 µg folic acid twice a day. The main outcome measure was the incidence of GDM in both groups. Secondary outcome measures were as follows: the incidence of fetal macrosomia (>4,000 g), gestational hypertension, preterm delivery, caesarean section, shoulder dystocia, neonatal hypoglycemia, and neonatal distress respiratory syndrome. GDM diagnosis was performed according to the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) recommendations.

RESULTS

Incidence of GDM was significantly reduced in the myo-inositol group compared with the placebo group: 6 vs. 15.3%, respectively (P = 0.04). In the myo-inositol group, a reduction of GDM risk occurrence was highlighted (odds ratio 0.35). A statistically significant reduction of fetal macrosomia in the myo-inositol group was also highlighted together with a significant reduction in mean fetal weight at delivery. In the other secondary outcome measures, there were no differences between groups.

CONCLUSIONS

myo-Inositol supplementation in pregnant women with a family history of type 2 diabetes may reduce GDM incidence and the delivery of macrosomia fetuses.

Effects of metformin-diet intervention before and throughout pregnancy on obstetric and neonatal outcomes in patients with polycystic ovary syndrome

OBJECTIVE

Prospectively assess whether metformin/diet pre-conception and throughout pregnancy would safely reduce first trimester miscarriage and improve pregnancy outcomes in women with polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

In 76 PCOS women, first pregnancy miscarriage and live birth were compared before and on metformin/diet, started 6.8 months (median) before conception, continued throughout pregnancy. On metformin 2-2.55 g/day, low glycemic index diet, first pregnancy outcomes in PCOS were compared with 156 community obstetric practice women (controls).

MAIN OUTCOME MEASURES

Live births, miscarriage, birth <37 weeks gestation, gestational diabetes, pre-eclampsia, fetal macrosomia.

RESULTS

In 76 PCOS women before metformin-diet, there were 36 miscarriages (47%) and 40 live births vs. 14 (18%) miscarriages and 62 live births on metformin-diet 6.8 months before conception and throughout pregnancy, p = 0.0004, OR 3.99, 95% CI 1.91-8.31. On metformin-diet, PCOS women did not differ (p > 0.08) from controls for birth <37 weeks gestation, gestational diabetes, pre-eclampsia, or fetal macrosomia.

CONCLUSIONS

Metformin-diet before and during pregnancy in PCOS reduces miscarriage and adverse pregnancy outcomes. Study limitation: individual benefits of the diet alone and diet plus metformin could not be assessed separately. Randomized, controlled clinical trials now need to be done with a larger number of patients.

Effects of metformin use in pregnant patients with polycystic ovary syndrome

Use of metformin throughout pregnancy in women with polycystic ovary syndrome (PCOS) has shown to reduce the rates of early pregnancy loss, preterm labor, and prevention of fetal growth restriction. Metformin has been shown to have encouraging effects on several metabolic aspects of polycystic ovarian syndrome, such as insulin sensitivity, plasma glucose concentration and lipid profile and since women with PCOS are more likely than healthy women to suffer from pregnancy-related problems like early pregnancy loss, gestational diabetes mellitus and hypertensive states in pregnancy, the use of metformin therapy in these patients throughout pregnancy may have beneficial effects on early pregnancy loss and development of gestational diabetes.

Overweight, obesity and central obesity in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND Polycystic ovary syndrome (PCOS) is closely associated with obesity but the prevalence of obesity varies between published studies. The objective of this research was to describe the prevalence of overweight, obesity and central obesity in women with and without PCOS and to assess the confounding effect of ethnicity, geographic regions and the diagnostic criteria of PCOS on the prevalence. METHODS MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting the prevalence of overweight, obesity or central obesity in women with and without PCOS. Data were presented as prevalence (%) and risk ratio (RR) [95% confidence interval (CI)]. Random-effect models were used to calculate pooled RR. RESULTS This systematic review included 106 studies while the meta-analysis included 35 studies (15129 women). Women with PCOS had increased prevalence of overweight [RR (95% CI): 1.95 (1.52, 2.50)], obesity [2.77 (1.88, 4.10)] and central obesity [1.73 (1.31, 2.30)] compared with women without PCOS. The Caucasian women with PCOS had a greater increase in obesity prevalence than the Asian women with PCOS compared with women without PCOS [10.79 (5.36, 21.70) versus 2.31 (1.33, 4.00), P < 0.001 between subgroups). CONCLUSIONS Women with PCOS had a greater risk of overweight, obesity and central obesity. Although our findings support a positive association between obesity and PCOS, our conclusions are limited by the significant heterogeneity between studies and further studies are now required to determine the source of this heterogeneity. Clinical management of PCOS should include the prevention and management of overweight and obesity.

Myo-inositol may prevent gestational diabetes in PCOS women

To evaluate retrospectively the prevalence of gestational diabetes (GD) in pregnancies obtained with myo-inositol administration in women with polycystic ovary syndrome. A total of 98 pregnancies in PCOS women obtained in a 3-year period, either with myo-inositol (n. 54), or with metformin (n. 44) were considered. While myo-inositol was assumed through the whole pregnancy, the group of women treated with metformin stopped the drug assumption after pregnancy diagnosis, and was considered as a control group. After having eliminated cases of miscarriages and twin pregnancies, a definitive number of 46 women in the myo-inositol group and 37 in the control group was taken in account to be retrospectively evaluated. The primary outcome measure was GD occurrence in both groups; whereas secondary outcome measures were pregnancy outcomes: hypertensive disorders, pre-term birth, macrosomia and caesarean section occurrence. Prevalence of GD in the myo-inositol group was 17.4% versus 54% in the control group, with a highly significant difference also after adjusting for covariates. Consequently, in the control group the risk of GD occurrence was more than double compared to the myo-inositol group, with an odds ratio 2.4 (confidence interval 95%, 1.3-4.4). There was no difference between the groups in relation to secondary outcome measures. This study suggests a possible effect of myo-inositol in the primary prevention of GD in PCOS women.

The risk of gestational diabetes mellitus among Mexican women with a history of infertility and polycystic ovary syndrome

OBJECTIVE

To study the incidence of gestational diabetes mellitus (GDM) in Mexican women with a history of infertility and polycystic ovary syndrome (PCOS) compared with women without PCOS matched by age, pregestational body mass index (BMI), and parity.

DESIGN

Historic cohort study.

SETTING

Level three medical institution.

PATIENT(S)

Group 1 (n = 52), women with a history of infertility and PCOS, and group 2 (n = 52), women without PCOS. Inclusion criteria were singleton pregnancy with ≤ 13 weeks of gestation. Exclusion criteria were pregestational diabetes mellitus and/or concomitant diseases.

INTERVENTION(S)

Diagnosis of GDM was based on a 3-hour, 100-g oral glucose tolerance test (GTT) performed during the second trimester.

MAIN OUTCOME MEASURE(S)

Incidence and relative risk (RR) for GDM.

RESULT(S)

The incidence of GDM was 26.9% and 9.6% for groups 1 and 2, respectively (RR = 2.8; 95% confidence interval 1.08-7.2). No other between-group differences were observed in the incidence of miscarriage, preterm birth, premature rupture of membranes, preeclampsia, stillbirth, fetal malformations, or small or large for gestational age newborns.

CONCLUSION(S)

Pregnant Mexican women with a history of infertility and PCOS are at increased risk for developing GDM. This risk should be considered beginning early in the second trimester for a timely intervention and to improve the maternal-fetal prognosis.

The risk of a persistent glucose metabolism impairment after gestational diabetes mellitus is increased in patients with polycystic ovary syndrome

OBJECTIVE

To test the hypothesis that the risk of persistent glucose impairment after gestational diabetes mellitus (GDM) is increased in patients with polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

The prospective case-control study included 42 pregnant patients with PCOS and GDM and 84 pregnant control patients with GDM but without clinical and biochemical hyperandrogenism, polycystic ovaries, and oligo-anovulation. The case and control subjects were matched one to two for age and BMI. The glycemic profiles were studied in all subjects 6 weeks, 12 weeks, and 18 months after delivery. The incidence and the relative risk (RR) were calculated for overall persistence of an abnormal glycemic pattern and for each specific alteration, i.e., impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and diabetes mellitus (DM).

RESULTS

At 18 months after delivery, the incidences of IFG, IGT, and IFG-IGT were significantly (P < 0.05) higher in the cases than in the controls. At the 18-month follow-up, the RR for the composite outcome of glucose metabolism impairment in PCOS women was 3.45 (95% CI 1.82-6.58).

CONCLUSIONS

Patients with PCOS are at increased risk for a persistent impaired glucose metabolism after GDM.

Can metformin reduce the incidence of gestational diabetes mellitus in pregnant women with polycystic ovary syndrome? Prospective cohort study

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are at a high risk to develop Gestational Diabetes mellitus (GDM). We hypothesized that metformin due to its metabolic, endocrine, vascular, and anti-inflammatory effects may reduce the incidence of GDM in PCOS women.

PATIENT AND METHOD

We carried out a prospective cohort study to determine the beneficial effects of metformin on PCOS patients during pregnancy. Three-hundred and sixty non-diabetic PCOS patients were included who were conceived on metformin by different treatment modalities. Two-hundred pregnant women continued on metformin at a dose of 1000-2000 mg daily throughout pregnancy (study group) and 160 women discontinued metformin use at the time of conception (control group).

RESULTS

There is a statistically significant reduction in the incidence of GDM in favor of metformin group (OR: 0.17, 95% CI: 0.07-0.37). There is a statistically significant reduction in the incidence of pre-eclampsia in favor of metformin group (OR: 0.35, 95% CI: 0.13-0.94).

CONCLUSION

Metformin is a promising medication for the prevention or reduction of the incidence of GDM and pre-eclampsia in PCOS women.

Use of metformin in the treatment of polycystic ovary syndrome

Metformin is quite an old drug, but it is optimal for the control of glycemia in Type 2 diabetes. It was reported, 15 years ago, that insulin resistance was abnormally high in most polycystic ovary syndrome (PCOS) patients. Starting from that moment, increasing numbers of studies were performed to demonstrate the efficacy of metformin in controlling and/or modulating several aspects of PCOS, which is the most common cause of menstrual irregularity, inesthetisms and infertility. Metformin induces higher glucose uptake, thus inducing a lower synthesis/secretion of insulin. Such an effect permits the possible restoration of the normal biological functions that are severely affected by the compensatory hyperinsulinemia reactive to the increased peripheral insulin resistance. These are the basis of the many positive effects of this drug, such as the restoration of menstrual cyclicity, ovulatory cycles and fertility, because abnormal insulin levels affect the hypothalamus-pituitary-ovarian function, as well as the use of glucose in peripheral tissues. Metformin improves the impairments typically observed in hyperinsulinemic PCOS patients, reducing the possible evolution towards metabolic syndrome and Type 2 diabetes; and when pregnancy occurs, it consistently reduces the risk of gestational diabetes, eclampsia and hypertension. PCOS seems to be the perfect physiopathological condition that might have higher benefits from metformin administration, obviously after Type 2 diabetes. This review focuses on the many aspects of PCOS and on the possible issues of this disease for which metformin might be a putative optimal treatment.

Outcomes in women with a history of gestational diabetes. Screening and prevention of type 2 diabetes. Literature review

Women with a history of gestational diabetes mellitus (GDM) are characterized by a high risk of type 2 diabetes mellitus (T2DM) (x 7), metabolic syndrome (x 2 to 5) and cardiovascular diseases (x 1,7). Women with lesser degrees of glucose intolerance share the same risks. T2DM may occur from post-partum (5 to 14%) to several years later, up to 25 years. Some factors associated with T2DM are identified: obesity, early diagnosis of GDM before 24 weeks gestation, high pregnancy OGTT blood glucose or insulin-therapy during GDM. Screening for T2DM only with fasting glucose provides less sensibility than with OGTT; HbA1c may supplant these dosages. The recurrence rate of GDM is between 30 and 84%, non-white ethnicity and insulinotherapy during GDM being the best proven predictors. High risk women need repeated life-long screenings for glycaemic abnormalities, or when another pregnancy is planned. Among obese women with history of GDM who show minor glycoregulation disturbances, modifications of lifestyle in intensive programs or metformin halve the risk of DT2. However, studies analysing practices show low adhesion to screening; without an intensive program, few women implement lifestyle modifications. These intensive programs should be implemented and proposed to high-risk women. Their therapeutic education should also include prevention of cardiovascular risk factors.

Oral hypoglycemic agents for gestational diabetes mellitus?

INTRODUCTION

Gestational diabetes mellitus (GDM), the most frequent medical complication of pregnancy, is associated with several adverse outcomes over the short- and long-term for both mother and offspring. Standard treatment for GDM consists of insulin injections. Oral hypoglycemic agents (OHAs), on the other hand, are still the subject of controversy. Although OHAs are seemingly as efficient as insulin and may provide better quality of life, congenital malformations and unknown long-term effects are still feared.

AREAS COVERED

Recent data on the pharmacokinetics of two OHAs (glyburide and metformin) and their clinical use for GDM are reviewed, with a focus on clinical trials and observational studies comparing insulin with glyburide or metformin (1960 - 2010). The review will provide a comprehensive overview of the pros and cons of OHA usage, an appreciation of OHAs' efficiency for the purpose of controlling glycemia and embryogenetic basics relating to congenital malformations.

EXPERT OPINION

While insulin treatment is an effective therapy for controlling maternal glycemia, it nevertheless requires sufficient education and skills on the part of the patient to manage properly and may cause hypoglycemia, fear and anxiety. Oral treatment as a more user-friendly alternative may thus facilitate the control of GDM in some patients.

Hyperinsulinemia and metabolic syndrome at mean age of 10 years in black and white schoolgirls and development of impaired fasting glucose and type 2 diabetes mellitus by mean age of 24 years

The objective of the study was to evaluate preteen insulin and metabolic syndrome (MS) as independent predictors of impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) in black and white females by mean age of 24 years. This was a prospective cohort study. There were 8 measures of fasting glucose and insulin from mean age of 10 years through mean age of 24 years, and insulin also at mean age of 25 years. Childhood MS was defined by at least 3 abnormal values among waist circumference, triglyceride, high-density lipoprotein cholesterol, blood pressure, and glucose. Hyperinsulinemia was defined by insulin greater than or equal to race-specific 75th percentile. Patients with type 1 diabetes mellitus were excluded. The study was held in schools and in an outpatient clinical center. Participants were schoolgirls (260 white, 296 black). There was no intervention. The outcome measures were IFG (fasting glucose of at least 100 to 125 mg/dL) and T2DM (fasting glucose of at least 126 mg/dL). By the age of 24 years, there were 11 cases of T2DM (2%) and 108 cases of IFG (19%). By the age of 24 years, IFG + T2DM was present in 18% of women (73/412) who had normal insulin-no MS at the age of 10 years vs 28% (34/122) of those with high insulin-no MS at the age of 10 years (P = .014) and 67% (10/15) of those with high insulin + MS at the age of 10 years (P < .0001). By stepwise logistic regression, significant, independent, positive predictors of IFG + T2DM were first insulin measure in childhood, age at last sampling, childhood MS, change in body mass index over 15 years, and, separately, initial glucose of at least 100 mg/dL and average of all insulin quartile ranks over 15 years. The correlation between childhood insulin z score and insulin z score 15 years later was r = .30, P < .0001. Insulin and MS at a mean age of 10 years plus change in body mass index over 15 years, and 15-year average insulin rank independently predict IFG + T2DM by mean age of 24 years, suggesting avenues for primary prevention.

[Outcomes in women with history of gestational diabetes mellitus. Screening and prevention of type 2 diabetes mellitus. Literature review]

Women with a history of gestational diabetes mellitus (GDM) are characterized by a high risk of type 2 diabetes mellitus (T2DM) (X 7), metabolic syndrome (X 2 to 5) and cardiovascular diseases (X 1,7). Women with lesser degrees of glucose intolerance share the same risks. T2DM may occur from postpartum (5 to 14%) to several years later, up to 25 years. Some factors associated with T2DM are identified: obesity, early diagnostic before 24 weeks, high pregnancy OGTT blood glucose or insulinotherapy. Screening for T2DM only with fasting glucose provides less sensibility than with OGTT; HbA1c may supplant these dosages. The recurrence rate of GDM is between 30 and 84%, non-white ethnicity and insulinotherapy during GDM being the best proven predictors. High risk women need repeated life-long screenings for glycemic abnomalies, or when another pregnancy is planned. Among overweight or obese women with history of GDM who show minor glycoregulation disturbances, it is proved that modifications of lifestyle in intensive programs or metformin halve the risk of DT2. However, studies analysing practices show low adhesion to screening; without an intensive program, few women implement lifestyle modifications. These intensive programs should be implemented and proposed to high-risk women. Their therapeutic education should also include prevention of cardiovascular risk factors.

Metformin versus placebo from first trimester to delivery in polycystic ovary syndrome: a randomized, controlled multicenter study

CONTEXT

Metformin is widely prescribed to pregnant women with polycystic ovary syndrome (PCOS) in an attempt to reduce pregnancy complications. Metformin is not approved for this indication, and evidence for this practice is lacking.

OBJECTIVES

Our objective was to test the hypothesis that metformin, from first trimester to delivery, reduces pregnancy complications in women with PCOS.

DESIGN AND SETTING

We conducted a randomized, placebo-controlled, double-blind, multicenter study at 11 secondary care centers.

PARTICIPANTS

The participants were 257 women with PCOS, in the first trimester of pregnancy, aged 18-42 yr.

INTERVENTION

We randomly assigned 274 singleton pregnancies (in 257 women) to receive metformin or placebo, from first trimester to delivery.

MAIN OUTCOME MEASURES

The prevalence of preeclampsia, gestational diabetes mellitus, preterm delivery, and a composite of these three outcomes is reported.

RESULTS

Preeclampsia prevalence was 7.4% in the metformin group and 3.7% in the placebo group (3.7%; 95% CI, -1.7-9.2) (P=0.18). Preterm delivery prevalence was 3.7% in the metformin group and 8.2% in the placebo group (-4.4%; 95%, CI, -10.1-1.2) (P=0.12). Gestational diabetes mellitus prevalence was 17.6% in the metformin group and 16.9% in the placebo group (0.8%; 95% CI, -8.6-10.2) (P=0.87). The composite primary endpoint prevalence was 25.9 and 24.4%, respectively (1.5%; 95% CI, -8.9-11.3) (P=0.78). Women in the metformin group gained less weight during pregnancy compared with those in the placebo group. There was no difference in fetal birth weight between the groups.

CONCLUSIONS

Metformin treatment from first trimester to delivery did not reduce pregnancy complications in PCOS.

Fertility treatment in women with polycystic ovary syndrome: a decision analysis of different oral ovulation induction agents

OBJECTIVE

To compare different oral ovulation induction agents in treating infertile women with polycystic ovary syndrome (PCOS).

DESIGN

Decision-analytic model comparing three treatment strategies using probability estimates derived from literature review and sensitivity analyses performed on the baseline assumptions.

SETTING

Outpatient reproductive medicine and gynecology practices.

PATIENT(S)

Infertile women with PCOS.

INTERVENTION(S)

Metformin, clomiphene citrate, or metformin with clomiphene citrate.

MAIN OUTCOME MEASURE(S)

Live birth.

RESULT(S)

Within the baseline assumptions, combination therapy with metformin and clomiphene citrate was the preferred therapy for achieving live birth in women with PCOS. Sensitivity analysis revealed the model to be robust over a wide range of probabilities.

CONCLUSION(S)

Combination therapy with metformin and clomiphene citrate should be considered as first-line treatment for infertile women with PCOS.

Role of metformin in the management of polycystic ovary syndrome

Polycystic ovary syndrome is the most common endocrinological disorder affecting 4-12% of women and also the most controversial. Metformin was logically introduced to establish the extent to which hyperinsulinaemia influences the pathogenesis of the condition. Early studies were very encouraging. Randomized controlled studies and several metaanalyses have changed the picture and put the drug that was once heralded as magic in a much contracted place. More work is needed to establish its right place in particular with regards to the prevention of many gestational and long-term complications.

Brick by brick: metformin for gestational diabetes mellitus?

Evaluation of: Balani J, Hyer SL, Rodin DA, Shehata H. Pregnancy outcomes in women with gestational diabetes treated with metformin or insulin: a case-control study. Diabet. Med. 26(8), 798-802 (2009). This paper reviews a case-control study, reported by Balani et al., comparing maternal and neonatal outcomes of women treated for gestational diabetes mellitus with either metformin or insulin. A cohort of 100 women treated with metformin alone, without insulin rescue, was compared with a retrospective cohort of 100 women treated with insulin. Results favored metformin. This paper discusses issues related to the safety and efficiency of metformin treatment during pregnancy, the attitudes of pregnant women toward treatment options, public health policy and the worldwide gestational diabetes mellitus epidemic, as well as the financial burden of therapy, particularly for developing countries. It also looks at the pathophysiology of gestational diabetes mellitus and the need for clinical trial assessment of combination oral-hypoglycemic therapy.

Dysglycemias in pregnancy: from diagnosis to treatment. Brazilian consensus statement

There is an urgent need to find consensus on screening, diagnosing and treating all degrees of dysglycemia that may occur during pregnancies in Brazil, considering that many cases of dysglycemia in pregnant women are currently not diagnosed, leading to maternal and fetal complications. For this reason the Brazilian Diabetes Society (SBD) and the Brazilian Federation of Gynecology and Obstetrics Societies (FEBRASGO), got together to introduce this proposal. We present here a joint consensus regarding the standardization of clinical management for pregnant women with any degree of dysglycemia, on the basis of current information, to improve medical assistance and to avoid related complications of dysglycemia in pregnancy to the mother and the fetus. This consensus aims to standardize the diagnosis among general practitioners, endocrinologists and obstetricians allowing the dissemination of information in basic health units, public and private services, that are responsible for screening, diagnosing and treating disglycemic pregnant patients.

Obesity and gestational diabetes

The prevalence of both obesity and gestational diabetes mellitus (GDM) is increasing worldwide. GDM affects about 7% of all pregnancies and is defined as any degree of impaired glucose tolerance during gestation. The presence of obesity has a significant impact on both maternal and fetal complications associated with GDM. These complications can be addressed, at least in part, by good glycaemic control during pregnancy. The significance and impact of obesity in women with GDM are discussed in this article, together with treatment options, the need for long-term risk modification and postpartum follow-up.

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.