The administration of metformin during pregnancy reduces polycystic ovary syndrome related gestational complications

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Changes in adverse obstetrical and neonatal outcomes over time in American women with polycystic ovary syndrome: an 11-year study of a population database

PURPOSE

To determine whether the prevalence in American demographic and resultant adverse obstetric outcomes changed in women with polycystic ovary syndrome between the years of 2004-2014 inclusively, based on data derived from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (HCUP-NIS) database.

METHODS

This is a retrospective population-based study using data derived from the HCUP-NIS database from the years of 2004-2014, inclusively. Within this group, all pregnancies to women with PCOS were identified and separated by year, creating 11 groups.

RESULTS

Risk factors including non-Caucasian race, lower socioeconomic status, and rates of obesity and thyroid disease increased over time. The rates of gestational diabetes mellitus demonstrated a slight decrease, (21.3% in 2004 to 18.0% in 2014, P = 0.01). The number of women with preterm premature rupture of membranes decreased from 3.0% in 2004 to 2.0% in 2014 (P = 0.04). Rates of preterm delivery decreased from 14.8% in 2004 to 9.8% in 2014 (P < 0.001). Rates of cesarean section decreased from 57.3% in 2004 to 45.7% in 2014 (P < 0.001), while rates of spontaneous vaginal delivery increased from 37.4% in 2004 to 50.1% in 2014 (P < 0.001). The rate of wound complications decreased from 2.1% in 2004 to 0.4% in 2014 (P < 0.001). However, the rate of congenital anomalies increased from 0.5% in 2004 to 1.2% in 2014 (P = 0.001).

CONCLUSIONS

In spite of increases in demographic risk factors associated with increased pregnancy complications, we hypothesize that the interventions made to minimize the risks of cesarean section and manage metabolic complications in women with PCOS during the period of study have resulted in improved pregnancy outcomes during the period of study.

Systematic review and meta-analysis of birth outcomes in women with polycystic ovary syndrome

It is unclear whether polycystic ovary syndrome (PCOS) is an independent risk factor for adverse birth outcomes in the offspring of affected women. Here, we investigate the association of PCOS with birth outcomes in the offspring of women with PCOS overall and by potential confounders. This systematic review and meta-analysis included 73 studies and 92,881 offspring of women with and without PCOS from inception until 13th July 2022. We report that mothers with PCOS are younger and have higher body mass index (BMI) around conception and have greater gestational weight gain. The odds of preterm birth, fetal growth restriction and low birth weight are higher and mean birthweight is lower in PCOS of which a lower mean birthweight and a higher small for gestational age are probably independent of BMI. This work informed the recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome, emphasizing that PCOS status should be captured at pregnancy to identify risk and improve birth outcomes in the offspring.

Systematic review and meta-analysis of pregnancy outcomes in women with polycystic ovary syndrome

Screening for polycystic ovary syndrome (PCOS) in antenatal care is inadequate, largely owing to the lack of clarity around whether PCOS is an independent risk factor for pregnancy complications. This systematic review and meta-analysis include 104 studies and 106,690 pregnancies in women with and without PCOS from inception until 13th July 2022. We report that women with PCOS are younger and have higher body mass index (BMI) around conception and have greater gestational weight gain. The odds of miscarriage, gestational diabetes mellitus, gestational hypertension, pre-eclampsia and cesarean section are higher in women with PCOS. The increased odds of adverse outcomes in PCOS remain significant when age and BMI are matched and when analyses are restricted to high-quality studies. This work informed the recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome, emphasizing that PCOS status should be captured in all women who are planning to, or have recently become pregnant to facilitate prevention of adverse outcomes and improve pregnancy outcomes.

Efficacy and safety of metformin during pregnancy: an update

During the last decades, gestational diabetes mellitus (GDM) prevalence has been on the rise. While insulin remains the gold standard treatment for GDM, metformin use during pregnancy is controversial. This review aimed to comprehensively assess the available data on the efficacy and safety of metformin during pregnancy, both for the mother and the offspring. Metformin has been validated for maternal efficacy and safety, achieving comparable glycemic control with insulin. Additionally, it reduces maternal weight gain and possibly the occurrence of hypertensive disorders. During the early neonatal period, metformin administration does not increase the risk of congenital anomalies or other major adverse effects, including lower APGAR score at 5 min, neonatal intensive care unit admissions, and respiratory distress syndrome. Several studies have demonstrated a reduction in neonatal hypoglycemia. Metformin has been associated with an increase in preterm births and lower birth weight, although this effect is controversial and depends on the indication for which it was administered. Evidence indicates possible altered fetal programming and predisposition to childhood obesity and metabolic syndrome during adulthood after use of metformin in pregnancy. With critical questions still requiring a final verdict, ongoing research on the field must be conducted.

Polycystic ovary syndrome and recurrent pregnancy loss, a review of literature

Objective

PCOS is a syndrome of ovarian dysfunction associated with recurrent pregnancy loss. Several correlating factors have been investigated that influence the risk of pregnancy loss in PCOS. However, uncertainty remains about their contribution to pregnancy loss and prognosis. This review of literature aims to identify what is known and what requires further investigation on the relationship between PCOS and recurrent pregnancy loss, to guide future research and optimize medical guidance throughout pregnancy.

Study design

a review of literature was performed on several search engines using the following terms; polycystic ovarian syndrome, PCOS, recurrent pregnancy loss, recurrent miscarriage, RPL, aborted fetus, abortus provocatus, miscarriage and habitual abortion.

Results

37 articles were included; 3 systematic reviews, 1 meta-analysis, 2 randomized controlled trials, 6 prospective cohort studies, 22 case-control studies and 3 case series. The main objectives investigated by studies were pregnancy complications, pregnancy loss and live birth in the PCOS population.

Conclusion

Studies that investigated the relationship between PCOS and recurrent pregnancy loss are few and inconsistent and warrant further research. Factors apt for further investigation include the extent to which PCOS phenotypes, BMI, obesity, insulin resistance, hyperandrogenemia, SHBG, hs-CRP, CTRP6, adiponectin, plasma leptin, homocysteine, AMH and thrombophilia contribute to further risk of miscarriage. Other factors requiring further exploration in relation to risk for miscarriage in PCOS patient with RPL include sOB-R, PAI-Fx and the Factor-V-Leiden mutations.

Placental Mitochondrial Function and Dysfunction in Preeclampsia

The placenta is a vital organ of pregnancy, regulating adaptation to pregnancy, gestational parent/fetal exchange, and ultimately, fetal development and growth. Not surprisingly, in cases of placental dysfunction-where aspects of placental development or function become compromised-adverse pregnancy outcomes can result. One common placenta-mediated disorder of pregnancy is preeclampsia (PE), a hypertensive disorder of pregnancy with a highly heterogeneous clinical presentation. The wide array of clinical characteristics observed in pregnant individuals and neonates of a PE pregnancy are likely the result of distinct forms of placental pathology underlying the PE diagnosis, explaining why no one common intervention has proven effective in the prevention or treatment of PE. The historical paradigm of placental pathology in PE highlights an important role for utero-placental malperfusion, placental hypoxia and oxidative stress, and a critical role for placental mitochondrial dysfunction in the pathogenesis and progression of the disease. In the current review, the evidence of placental mitochondrial dysfunction in the context of PE will be summarized, highlighting how altered mitochondrial function may be a common feature across distinct PE subtypes. Further, advances in this field of study and therapeutic targeting of mitochondria as a promising intervention for PE will be discussed.

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.

Pregnancy, perinatal and childhood outcomes in women with and without polycystic ovary syndrome and metformin during pregnancy: a nationwide population-based study

BACKGROUND

Polycystic Ovary Syndrome (PCOS) is an endocrine disorder that affects women in reproductive age and represents an unfavourable risk factor for several pregnancy and perinatal outcomes. Despite, no guidelines or pharmaceutical strategies for treating PCOS during pregnancy are available. The aim of this study is to determine the association between polycystic ovary syndrome with or without metformin and the pregnancy, perinatal outcomes as well as the risk of obesity in children born to these mothers.

METHODS

In this nationwide population-based cohort study based in Swedish population, all singleton births (n = 1,016,805) from 686,847 women since 2006 up to 2016 were included. Multivariable logistic and Cox regression modelling with odds ratios (OR) and hazard ratios (HR) and 95% confidence intervals were used to study the association between the exposure of maternal PCOS, metformin during pregnancy (or the combination of both) and: 1) Pregnancy outcomes: preeclampsia, gestational diabetes, caesarean section, and acute caesarean section, 2) Perinatal outcomes: preterm birth, stillbirth, low birth weight, macrosomia, Apgar < 7 at 5 min, small for gestational age and large for gestational age, and 3) Childhood Obesity.

RESULTS

PCOS in women without metformin use during pregnancy was associated with higher risks of preeclampsia (OR = 1.09, 1.02-1.17), gestational diabetes (OR = 1.71, 1.53-1.91) and caesarean section (OR = 1.08, 1.04-1.12), preterm birth (OR = 1.30, 1.23-1.38), low birth weight (OR = 1.29, 1.20-1.38), low Apgar scores (OR = 1.17, 1.05-1.31) and large for gestational age (OR = 1.11, 1.03-1.20). Metformin use during pregnancy (in women without PCOS) was associated with a 29% lower risks of preeclampsia (OR = 0.71, 0.51-0.97), macrosomia and large for gestational age. Obesity was more common among children born to mothers with PCOS without metformin (HR = 1.61, 1.44-1.81); and those with metformin without PCOS (HR = 1.67, 1.05-2.65). PCOS with metformin was not associated with any adverse outcome.

CONCLUSION

PCOS was associated with increased risks of adverse pregnancy and perinatal outcomes and childhood obesity. Metformin appears to reduce these risks in mothers with polycystic ovary syndrome and their children; but may increase the risk of childhood-obesity in children form women without PCOS.

Different pregnancy outcomes according to the polycystic ovary syndrome diagnostic criteria: a systematic review and meta-analysis of 79 studies

OBJECTIVE

To correlate the distinct diagnostic criteria of polycystic ovary syndrome (PCOS) with the development of maternal and neonatal complications.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Pregnant women with PCOS.

INTERVENTION(S)

Maternal and neonatal complications were compared among women with PCOS diagnosed with different criteria.

MAIN OUTCOME MEASURE(S)

The primary outcomes of gestational diabetes mellitus and preeclampsia (PE) were assessed for every diagnostic criterion.

RESULT(S)

Seventy-nine studies were included. Regarding gestational diabetes, the overall pooled prevalence was 14% (95% confidence interval [CI], 11%-18%; I², 97%), reaching the highest level when polycystic ovarian morphology on ultrasound and 1 of the remaining 2 Rotterdam criteria (1/2 Rotterdam criteria) were used (18%; 95% CI, 13%-24%; I², 20%) and the lowest when polycystic morphology on ultrasound and hyperandrogenism were used (3%; 95% CI, 0%-19%; I², not applicable). Regarding PE, the overall pooled prevalence was 5% (95% CI, 4%-7%; I², 82%). The highest PE prevalence was reported when the National Institutes of Health criteria were used (14%; 95% CI, 5%-33%; I², 90%) and the lowest when menstrual irregularities and 1 of the 2 Rotterdam criteria were used (2%; 95% CI, 1%-3%; I², not applicable).

CONCLUSION(S)

The prevalence of gestational diabetes mellitus in pregnant women with PCOS does not differ according to the criteria used; however, women diagnosed with PCOS per the National Institutes of Health criteria are at higher risk of PE.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Current Researches, Rationale, Plausibility, and Evidence Gaps on Metformin for the Management of Hypertensive Disorders of Pregnancy

Hypertensive disorders of pregnancy (HDP) are a group of morbid pregnancy complications, with preeclampsia (PE) being the most common subclassification among them. PE affects 2%–8% of pregnancies globally and threatens maternal and fetal health seriously. However, the only effective treatment of PE to date is the timely termination of pregnancy, albeit with increased perinatal risks. Hence, more emerging therapies for PE management are in urgent need. Originally introduced as the first-line therapy for type 2 diabetes mellitus, metformin (MET) has now been found in clinical trials to significantly reduce the incidence of gestational hypertension and PE in pregnant women with PE-related risks, including but not limited to pregestational diabetes mellitus, gestational diabetes mellitus, polycystic ovary syndrome, or obesity. Additionally, existing clinical data have preliminarily ensured the safety of taking MET during human pregnancies. Relevant lab studies have indicated that the underlying mechanism includes angiogenesis promotion, endothelial protection, anti-inflammatory effects, and particularly protective effects on trophoblast cells against the risk factors, which are beneficial to placental development. Together with its global availability, easy administration, and low cost, MET is expected to be a promising option for the prevention and treatment of PE. Nevertheless, there are still some limitations in current studies, and the design of the relevant research scheme is supposed to be further improved in the future. Herein, we summarize the relevant clinical and experimental researches to discuss the rationale, safety, and feasibility of MET for the management of HDP. At the end of the article, gaps in current researches are proposed. Concretely, experimental MET concentration and PE models should be chosen cautiously. Besides, the clinical trial protocol should be further optimized to evaluate the reduction in the prevalence of PE as a primary endpoint. All of those evidence gaps may be of guiding significance to improve the design of relevant experiments and clinical trials in the future.

Therapeutic doses of metformin do not have impact on angiogenesis in presence of sera from pre-eclamptic, IUGR and healthy pregnancies

Recent evidence suggests that metformin may prevent pre-eclampsia by reverting the angiogenic imbalance in maternal sera. In this study, we investigated effect of metformin on angiogenesis by quantifying tubule formation in a human-based in vitro test with co-culture of human adipose stromal cell (hASC) and human umbilical vein endothelial cell (HUVEC). A total of 20 pregnant women were recruited in the study. Serum samples were obtained from women with early- and late-onset pre-eclampsia and from women with pregnancies complicated by intrauterine growth restriction (IUGR) without pre-eclampsia (N = 5 in each of the three groups). Serum samples from women with healthy pregnancies served as controls (N = 5). The direct effect of metformin on angiogenesis was first assessed without maternal sera. Secondly, we investigated the impact of metformin on angiogenesis in the present of maternal sera. Metformin was used at 5, 50 and 600 µg/ml concentrations. Angiogenic and inflammatory biomarkers in maternal sera were analyzed by immunoassays. When the direct effect of metformin was studied, the two lowest concentrations of metformin did not affect tubule formation (angiogenesis), but the highest concentration inhibited angiogenesis. When metformin was supplemented at therapeutic concentrations of 5 and 50 µg/ml along with serum samples, there was no change in tubule formation in comparison to maternal sera alone. However, strong inhibitory effect on tubule formation was observed in all groups with the highest, non-therapeutic (600 µg/ml), concentration of metformin.

Antidiabetic drug metformin affects the developmental competence of cleavage-stage embryos

PURPOSE

Metformin is the most commonly prescribed drug in the management of metabolic disorders such as polycystic ovarian syndrome (PCOS) and gestational diabetes in women of reproductive age. Insulin-sensitizing effect of metformin helps in improving from PCOS features such as hyperandrogenism, anovulation, and infertility. However, its ability to cross placental barrier raises concern about safety of the drug on early embryonic development. In this study, we evaluated the effect of metformin on the ovarian function and embryo development.

METHODS

Adult Swiss albino female mice were administered with metformin (0, 50, 100, and 200 mg/kg body weight) for 4 weeks and assessed for reproductive function and preimplantation embryo development. Further, effect of metformin (0, 10, 25, 50, 100, 250, and 500 μg/mL) exposure to 2-cell-stage embryos was tested under in vitro conditions.

RESULTS

Metformin did not alter the body weight, blood glucose, ovarian weight, and follicular reserve. However, the early embryo development was significantly affected in mice treated with metformin in vivo at highest dose. Moreover, embryos which were exposed to metformin in vitro showed dose-dependent decline in blastocyst rate and hatching rate. Furthermore, at highest concentration of metformin (500 μg/mL), all the embryos were arrested at compaction stage.

CONCLUSION

The study revealed that metformin affects the early embryonic development and raises concern about its use during conception.

Ovulation Rate after Metformin and Clomiphene vs Clomiphene Alone in Polycystic Ovary Syndrome (PCOS): A Randomized, Double-Blind, Placebo-Controlled Trial

Background: Polycystic ovary syndrome (PCOS) affects 5%-15% of women of reproductive age and has a negative impact on their fertility. The primary outcome of this study is ovulation rate when standard (immediate release) metformin (MF) is added to clomiphene citrate (CC) in oligoovulatory and anovulatory women with PCOS.

Methods: This is a randomized, double-blind, placebo-controlled trial. Twenty-seven women with PCOS (according to the Rotterdam consensus), desiring pregnancy and without another cause of subfertility were recruited from a public hospital outpatient gynecology clinic. Up to six cycles of CC (25-150 mg) plus either MF 500 mg tds (CC+MF) or placebo (CC+Pl) were offered. Student’s t-test, Chi-squared test, and Fisher’s exact test were used for analysis.

Results: Thirteen women with up to six cycles each were included in the final analysis. The rate of ovulation and ovulation rate per cycle was similar between women in the CC+MF and CC+Pl groups RR 1.09 (95% CI 0.80-1.49) and RR 0.88 (95% CI 0.63-1.22), respectively as was chemical pregnancy rate RR 1.77 (95% CI 0.58-5.38). The live birth rate was higher in CC+MF RR 6.83 (95% CI 0.83-56.27) and miscarriage rate was lower RR 0.21 (95% CI 0.002-1.07). The number needed to treat for live birth was 10.

Conclusion: Use of standard MF, 500 mg tds, when given with CC results in an increase in live birth rate, and a decrease in miscarriage rate.

Metformin has a direct effect on ovarian cells that is dependent on organic cation transporters

Metformin (MET) is the most widely prescribed hypoglycemic drug in type 2 diabetes and Polycystic Ovary Syndrome. Besides its effects on glucose metabolism, MET exerts beneficial effects on these patients' fertility. However, the exact mechanisms of action of MET on female fertility are still unclear. In this work, we analyzed a possible direct effect of MET on ovarian cells. We found expression of the organic cation transporters OCT1, OCT2 and OCT3, responsible for MET uptake into the cells, in rat granulosa cells and human cumulus cells. Furthermore, MET increased pAMPK and decreased VEGF levels both in vivo and in rat granulosa cells in culture. These last effects were reversed when OCTs were inhibited. Our results suggest that MET acts directly on ovarian cells regulating cell metabolism and VEGF expression. Our findings are relevant to optimize PCOS fertility treatment and to explore ovarian MET actions in other female pathologies.

The role of maternal obesity in infant outcomes in polycystic ovary syndrome-A systematic review, meta-analysis, and meta-regression

Polycystic ovary syndrome (PCOS) is associated with worsened pregnancy and infant outcomes, higher body mass index (BMI), and longitudinal weight gain. Despite most of the clinical features of PCOS being risk factors for worsened infant outcomes in the general population, their impact on infant outcomes in PCOS is unknown. We aimed to investigate the association of PCOS with infant outcomes considering maternal adiposity, other known risk factors, and potential confounders. The meta-analyses included 42 studies in 7041 women with PCOS and 63 722 women without PCOS. PCOS was associated with higher gestational weight gain (GWG) and with higher preterm birth and large for gestational age and with lower birth weight with this association varying by geographic continent, PCOS phenotypes, and study quality. However, PCOS was associated with none of these outcomes on BMI-matched studies. Gestational diabetes was significantly associated with an increased preterm birth on meta-regression. We report for the first time that GWG is higher in PCOS. Infant outcomes vary by geographic continent and study quality but are similar in BMI-matched women with and without PCOS. This suggests that infant outcomes in PCOS may be related to maternal obesity. These novel findings warrant future studies in PCOS investigating screening and management of infant outcomes with consideration of maternal obesity.

Increased maternal pregnancy complications in polycystic ovary syndrome appear to be independent of obesity-A systematic review, meta-analysis, and meta-regression

Polycystic ovary syndrome (PCOS) is associated with an increased risk of maternal pregnancy and delivery complications. However, the impact of clinical features of PCOS and other potential risk factors in PCOS is still unknown. We aimed to investigate the association of PCOS with maternal pregnancy and delivery complications with consideration of risk factors and potential confounders. The meta-analysis included 63 studies. PCOS was associated with higher miscarriage, gestational diabetes mellitus, gestational hypertension, pre-eclampsia, induction of labour, and caesarean section. The association of PCOS with these outcomes varied by geographic continent, PCOS phenotypes, and study quality. Pre-eclampsia and induction of labour were not associated with PCOS on body mass index-matched studies. No outcome was associated with PCOS on assisted pregnancies. Age was significantly associated with higher miscarriage on meta-regression. There were no studies assessing perinatal depression. We confirm that PCOS is associated with an increased risk of maternal pregnancy and delivery complications. The association of PCOS with the outcomes is worsened in hyperandrogenic PCOS phenotypes, in specific geographic continents, and in the highest quality studies but disappears in assisted pregnancies. Future studies in PCOS are warranted to investigate proper timing for screening and prevention of maternal pregnancy and delivery complications with consideration of clinical features of PCOS.

Chronic hyperandrogenemia and western-style diet beginning at puberty reduces fertility and increases metabolic dysfunction during pregnancy in young adult, female macaques

STUDY QUESTION

What are the impacts of elevated testosterone (T) and an obesogenic western-style diet (WSD), either independently or together, on fertility and metabolic adaptations of pregnancy in primates?

SUMMARY ANSWER

Testosterone increases the time to achieve pregnancy, while a WSD reduces overall fertility, and the combination of testosterone and WSD additionally impairs glucose tolerance and causes pregnancy loss.

WHAT IS KNOWN ALREADY

Both hyperandrogenemia and obesity are hallmarks of polycystic ovary syndrome, which is a leading cause of infertility among women worldwide. Female macaques receiving T and WSD beginning at puberty show increased metabolic, ovarian and uterine dysfunction in the non-pregnant state by 3 years of treatment.

STUDY DESIGN, SIZE, DURATION

The same cohort of female rhesus macaques continued treatments from the time of puberty (2.5 years) to 4 years, including this fertility trial. There were four groups (n = 9-10/group): controls (C), T-treated (T; average total serum level 1.35 ng/ml), WSD-treated, and combined T and WSD-treated (T + WSD) females.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Females, which were typically having menstrual cycles, were paired for 4 days with a proven male breeder following the late follicular rise in circulating estradiol (≥100 pg/ml). The presence of sperm in the reproductive tract was used to confirm mating. Animals went through up to three successive rounds of mating until they became pregnant, as confirmed by a rise in circulating mCG during the late luteal phase and ultrasound evidence of a gestational sac at Day 30 post-mating (GD30). Placental vascular parameters were also measured at GD30. Metabolic measurements consisted of fasting levels of blood glucose and insulin at approximately GD30, 60, 90 and 115, as well as an intravenous (iv) glucose tolerance test (GTT) at GD115.

MAIN RESULTS AND THE ROLE OF CHANCE

While all animals in the C and T groups eventually became pregnant, T-treated females on average had a greater interval to achieve pregnancy (P < 0.05). However, only ~70% of animals in the WSD and T + WSD groups became pregnant (P < 0.004). One pregnancy in T + WSD group resulted in an anembryonic pregnancy which miscarried around GD60, while another T + WSD female conceived with a rare identical twin pregnancy which required cessation due to impending fetal loss at GD106. Thus, the number of viable fetuses was less in the T + WSD group, compared to C, T or WSD. Placental blood volume at GD30 was reduced in all treatments compared to the C group (P < 0.05). Maternal P4 levels were elevated in the WSD (P < 0.03) group and E2 levels were elevated in T + WSD animals (P < 0.05). An increase in serum A4 levels throughout gestation was observed in all groups (P < 0.03) except WSD (P = 0.3). All groups displayed increased insulin resistance with pregnancy, as measured from the ivGTT during pregnancy. However, only the T + WSD group had a significant increase in fasting glucose levels and glucose clearance during the GTT indicating a worsened glucose tolerance. WSD treatment decreased female fetuses third trimester weights, but there was an interaction between WSD and T to increase female fetal weight when normalized to maternal weight.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

The small number of pregnancies in the WSD and T + WSD groups hampers the ability to make definitive conclusions on effects during gestation. Also, the high fertility rate in the controls indicates the cohort was at their breeding prime age, which may impair the ability to observe subtle fertility defects. The low number of fetuses used for male and female analysis requires additional studies.

WIDER IMPLICATIONS OF THE FINDINGS

The current findings strongly suggest that both hyperandrogenemia and obesity have detrimental effects on fertility and gestation in primates, which may be directly relevant to women with polycystic ovary syndrome.

STUDY FUNDING/COMPETING INTEREST(S)

All ONPRC Cores and Units were supported by NIH Grant P51 OD011092 awarded to ONPRC. Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) of the National Institutes of Health (NIH) under Award Number P50HD071836 (to R.L.S.). The authors have no competing conflict of interests to disclose.

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.

ACOG Practice Bulletin No. 190: Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy. However, debate continues to surround the diagnosis and treatment of GDM despite several recent large-scale studies addressing these issues. The purposes of this document are the following: 1) provide a brief overview of the understanding of GDM, 2) review management guidelines that have been validated by appropriately conducted clinical research, and 3) identify gaps in current knowledge toward which future research can be directed.

Metformin in Pregnancy: Mechanisms and Clinical Applications

Metformin use in pregnancy is increasing worldwide as randomised controlled trial (RCT) evidence is emerging demonstrating its safety and efficacy. The Metformin in Gestational Diabetes (MiG) RCT changed practice in many countries demonstrating that metformin had similar pregnancy outcomes to insulin therapy with less maternal weight gain and a high degree of patient acceptability. A multicentre RCT is currently assessing the addition of metformin to insulin in pregnant women with type 2 diabetes. RCT evidence is also available for the use of metformin in pregnancy for women with Polycystic Ovarian Syndrome and for nondiabetic women with obesity. No evidence of an increase in congenital malformations or miscarriages has been observed even when metformin is started before pregnancy and continued to term. Body composition and metabolic outcomes at two, seven, and nine years have now been reported for the offspring of mothers treated in the MiG study. In this review, we will briefly discuss the action of metformin and then consider the evidence from the key clinical trials.

Pharmacogenetics of oral antidiabetic therapy

Type 2 diabetes prevalence is still on the rise worldwide. Antidiabetic drugs are widely prescribed to patients with Type 2 diabetes. Most patients start with metformin which is mostly well tolerated. However, a high percentage of patients fail to achieve glycemic control. The effectiveness of metformin as well as most other antidiabetic drugs depends among other factors on interindividual genetic differences that are up to now ignored in the treatment of Type 2 diabetes. Interestingly, many genes influencing the effectiveness of antidiabetic drugs are Type 2 diabetes risk genes making matters worse. Here, we shed light on these interindividual genetic differences.

The diversity of gestational diabetes: a therapeutic challenge

Metformin as the first drug of choice for glucose lowering in gestational diabetes (GDM) is still controversial, despite recent publications reporting similar outcomes in comparison to insulin, both for offspring and mothers. The use of metformin during pregnancy is increasing and several recent guidelines recommend metformin use in GDM pregnancies. Background, current metformin use and unresolved concerns are discussed in the context of the article from Gante and coworkers.

Risk of pre-eclampsia in women taking metformin: a systematic review and meta-analysis

AIMS

To perform meta-analyses of studies evaluating the risk of pre-eclampsia in high-risk insulin-resistant women taking metformin prior to, or during pregnancy.

METHODS

A search was conducted of the Medline, EMBASE, Web of Science and Scopus databases. Both randomized controlled trials and prospective observational cohort studies of metformin treatment vs. placebo/control or insulin either prior to or during pregnancy were selected. The main outcome measure was the incidence of pre-eclampsia in each treatment group.

RESULTS

Overall, in five randomized controlled trials comparing metformin treatment (n = 611) with placebo/control (n = 609), no difference in the risk of pre-eclampsia was found [combined/pooled risk ratio (RR), 0.86 (95% CI 0.33-2.26); P = 0.76; I²  = 66%]. Meta-analysis of four cohort studies again showed no significant effect [RR, 1.21 (95% CI 0.56-2.61); P = 0.62; I²  = 30%]. A meta-analysis of eight randomized controlled trials comparing metformin (n = 838) with insulin (n = 836), however, showed a reduced risk of pre-eclampsia with metformin [RR, 0.68 (95% CI 0.48-0.95); P = 0.02; I²  = 0%]. No heterogeneity was present in the metformin vs. insulin analysis of randomized controlled trials, whereas high levels of heterogeneity were present in studies comparing metformin with placebo/control. Pre-eclampsia was a secondary outcome in most of the studies. The mean weight gain from time of enrolment to delivery was lower in the metformin group (P = 0.05, metformin vs. placebo; P = 0.004, metformin vs. insulin).

CONCLUSIONS

In studies randomizing pregnant women to glucose-lowering therapy, metformin was associated with lower gestational weight gain and a lower risk of pre-eclampsia compared with insulin.

Therapeutic approach for metabolic disorders and infertility in women with PCOS

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder affecting 5-10% of women of reproductive age. It generally shows with oligo/amenorrhea, anovulatory cycles, clinical o biochemical hirsutism, polycystic ovaries and, in a significant percentage of cases, insulin resistance. PCOS is defined as a multifactorial pathology, determined by the association of many factors: genetic, endocrine and environmental. The first and most effective treatment of PCOS is to change life-style and lose weight. The use of oral contraceptives has been shown effective in reducing acne and hirsutism and regulates the menstrual cycle. For women with severe hirsutism, the addition of antiandrogens to estrogen-progestin therapy has significantly improved the results. In cases of anovulatory infertility, the drug of first choice is clomiphene citrate, followed by low-dose gonadotropins. Recently, insulin-sensitizing drugs have been widely prescribed for PCOS patients. They are particularly effective in reducing insulin resistance and improving ovulatory performance. Besides insulin-sensitizing drugs, natural substances, such as inositol, seems to have good efficacy, similar to metformin with fewer side effects. New substances that could be used include statins and natural statins, such as monakolin, alone or combined with myo-inositol. These substances do not have side effects and greatly reduce the hyperandrogenic component in these patients.

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.

Should metformin be included in fertility treatment of PCOS patients?

Metformin, a drug developed for the treatment of patients with type II diabetes, has become commonly prescribed medication for PCOS patients. Initially, metformin was prescribed for patients with impaired glucose tolerance at the pre conception period, however more recently its use was expanded to many of the PCOS patients and for the whole duration of pregnancy. Several studies examining the effects of Metformin during pregnancy reported a lower pregnancy loss, reduced gestational diabetes and no increased risk for birth defects, however, several more recent studies also raised concerns about its safe use. The therapeutic effect of metformin stems from its ability to inhibit the action of the first complex of the electron transport resulting in reduced ATP production. At the initial stages of embryo development, the only source of ATP is the mitochondrial electron transport chain. Lowering ATP production at the critical stage of early embryo development may impair oocyte maturation and embryo development as well as reprogram the metabolic characteristics of the offspring.

Effects of metformin on pregnancy outcomes in women with polycystic ovary syndrome: A meta-analysis

AIM

The aim of the study is to evaluate the effects of metformin on pregnancy outcomes in women with polycystic ovary syndrome (PCOS).

METHODS

We searched electronic databases and bibliographies of relevant papers to identify studies comparing the pregnancy outcomes in the metformin group with those in the placebo or blank control group. Then, we did this meta-analysis based on the PRISMA guidelines. The primary outcomes included early pregnancy loss (EPL), preterm delivery, term delivery, and gestational diabetes mellitus (GDM). Secondary outcomes included pregnancy-induced hypertension (PIH), intrauterine growth restriction (IUGR), fetal malformation, vaginal delivery (VD), cesarean section (CS), and metformin's side effects, such as nausea or gastrointestinal discomfort. Certainly, data about neonatal death and macrosomia were analyzed if data available.

RESULTS

Finally, 13 studies including 5 randomized controlled trials (RCT) and 8 cohort studies involving 1606 pregnant women with PCOS were analyzed. The pooled OR of EPL was 0.19 with obvious statistical significance, manifesting that metformin help to lower the rate of EPL (95% CI 0.12-0.28, P < 0.00001). Simultaneously, metformin showed the advantage of reducing the prevalence of preterm delivery (OR 0.37, 95% CI 0.20-0.68, P = 0.002). In addition, metformin could promote term delivery greatly and the pooled OR was 5.23 with sharp statistical difference (95% CI 3.12-8.75, P < 0.00001).

CONCLUSION

Metformin treatment in women with PCOS throughout pregnancy could increase the possibility of term delivery, VD and reduce the risk of EPL, preterm labor, pregnancy complications such as GDM and PIH, with no serious side effects. Moreover, metformin was not teratogenic based on the limited data. So we may recommend metformin treatment for women with PCOS during the whole pregnancy period for it is quite beneficial and safe for both mothers and babies.

Polycystic ovary syndrome and insulin: our understanding in the past, present and future

Insulin resistance is prevalent in women with polycystic ovary syndrome (PCOS), and plays a critical pathophysiologic role in both the metabolic and reproductive complications of PCOS. This review focuses on the contribution of insulin resistance to anovulation in PCOS and to the high risk for Type 2 diabetes, metabolic syndrome and early cardiovasular disease. Key points for clinicians emphasized by this review are the following: PCOS is a clinical diagnosis and alternative diagnoses must be excluded; PCOS carries an inherent risk of insulin resistance and, hence, metabolic consequences for which women with PCOS should be screened regardless of BMI or degree of obesity; and PCOS is associated with infertility and this should be discussed early on in care of women diagnosed with PCOS, recognizing that there are several possible strategies to address infertility in women with PCOS, each with its own risks and benefits.

Metformin in gestational diabetes: An emerging contender

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance occurring first time during pregnancy. Its prevalence is simultaneously increasing with the global rise of diabesity. GDM commonly develops, when maternal glucose metabolism is unable to compensate for the progressive development of insulin resistance, arising primarily from the consistently rising diabetogenic placental hormones. It classically develops during the second or third trimester. Theoretically, insulin sensitizers should have been the ideal agent in its treatment, given the insulin resistance, the major culprit in its pathogenesis. Fortunately, majority of women can be treated satisfactorily with lifestyle modification, and approximately 20% requires more intensive treatment. For several decades, insulin has been the most reliable treatment strategy and the gold standard in GDM. Metformin is effective insulin sensitizing agent and an established first line drug in type 2 diabetes currently. As it crosses the placenta, a safety issue remains an obstacle and, therefore, metformin is currently not recommended in the treatment of GDM. Nevertheless, given the emerging clinically equivalent safety and efficacy data of metformin compared to insulin, it appears that it may perhaps open a rather new door in managing GDM. The aim of this review is to critically analyze, the safety and efficacy data of metformin regarding its use in GDM and pregnant mothers with polycystic ovarian disease, which has emerged in past decades.

Oral antidiabetic agents in gestational diabetes: a narrative review of current evidence

Gestational diabetes mellitus (GDM) classically occurs when maternal glucose metabolism is unable to compensate the progressive development of insulin resistance that arises from the continuously rising diabetogenic placental hormones. Although most women can be treated satisfactorily with diet alone, some require more intensive treatment. Insulin has been the most reliable treatment strategy in GDM over several decades. Although a long time has passed since the publication of two randomized controlled trials suggesting comparable efficacy and safety of metformin and glibenclamide, international bodies have not yet approved these oral agents. However, with the consistently emerging efficacy and safety data of these two drugs in the past decade, they may perhaps open a rather new door. The aim of this narrative review is to critically evaluate the existing evidence regarding safety and efficacy of oral drugs in GDM accumulated since the first publication in year 2000, suggesting clinical equivalency of glibenclamide (glyburide).

Modulation of the IGF system and proliferation in human endometrial stromal cells by metformin: a dose-dependent effect

PURPOSE

To assess the metformin effect on endometrial stromal cell decidualization, proliferation, gene and protein expression of IGFBPs, IGFs and their receptors.

METHODS

Human endometrial stromal cells (hESCs) were cultured from endometrial biopsies of 11 women undergoing surgery for benign reasons. hESCs were decidualized with and without metformin in increasing doses. Supernatant and cells were harvested after decidualization for 12-14 days, followed by real-time PCR of IGFBP 1-6, IGF I, IGF II and their receptors. Prolactin, and IGFBP-1, -3, and -6 were additionally analyzed in supernatant by ELISA. Proliferation of hESCs and decidualization of hESCs were assessed under the influence of metformin. Data were analyzed using the paired t test with p < 0.05 considered significant.

RESULTS

While lower concentrations of metformin (10(-4), 10(-5 )M) did not influence the decidualization and proliferation capacity of hESCs, higher concentrations (10(-3), 10(-2 )M metformin) significantly (p < 0.05) diminished decidualization, as well as stromal cell proliferation in a dose-dependent manner. Higher concentrations of metformin lead to a significant (p < 0.05) dose-dependent attenuation of the progesterone effect with regard to IGFBP-1, -3, -5, -6, as well as IGF I receptor, while it did not change the expression of IGFBP-2 and -4, IGF I and II and the IGF II receptor. This was confirmed on the protein level for IGFBP-1, -3, and -6.

CONCLUSION

We were able to demonstrate for the first time a dose-dependent local effect of metformin within hESCs. Metformin might therefore influence locally the endometrial proliferation and maturation, and could open up new treatment options for gynecological diseases by vaginal application of metformin.

Efficacy of metformin on pregnancy complications in women with polycystic ovary syndrome: a meta-analysis

OBJECTIVE

To evaluate the efficacy of metformin administration throughout pregnancy on pregnancy-related complications in women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

MEDLINE and ScienceDirect were searched to retrieve relevant trials. The endpoint was the incidence of complications of pregnancy, gestational diabetes mellitus (GDM), pre-eclampsia (PE), miscarriage and premature birth included.

RESULTS

Five studies with 502 PCOS patients with metformin administration throughout pregnancy and 427 controls who used metformin just to get conception were included in our meta-analysis. In study group, a significantly lower change of emerging miscarriage and premature birth was observed, the pooled relative risk (RR) was 0.32 (95% confidence interval (CI): 0.19-0.56) for miscarriage and 0.40 (95%CI: 0.18-0.91) for premature birth. No significant difference was demonstrated in emerging GDM and PE.

CONCLUSIONS

Metformin therapy throughout pregnancy can reduce the RR of miscarriage and premature birth incidence in PCOS patients with no serious side effects.

Exposure of mouse embryonic pancreas to metformin enhances the number of pancreatic progenitors

AIMS/HYPOTHESIS

Developing beta cells are vulnerable to nutrient environmental signals. Early developmental processes that alter the number of pancreatic progenitors can determine the number of beta cells present at birth. Metformin, the most widely used oral agent for treating diabetes, alters intracellular energy status in part by increasing AMP-activated protein kinase (AMPK) signalling. This study examined the effect of metformin on developing pancreas and beta cells.

METHODS

Pancreatic rudiments from CD-1 mice at embryonic day 13.0 (E13.0) were cultured with metformin, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR, an AMPK activator) or vehicle control in vitro. In another set of studies, pregnant C57BL/6 mice were treated with metformin throughout gestation. Embryonic (E14.0) and neonatal pancreases were then analysed for their morphometry.

RESULTS

In vitro metformin treatment led to an increase in the proliferation and number of pancreatic duodenal homeobox 1-positive (PDX1(+)) progenitors. These results were reproduced by in vitro culture of embryonic pancreas rudiments with AICAR, suggesting that AMPK activation was involved. Similarly, metformin administration to pregnant dams induced an increase in both PDX1(+) and neurogenin 3-positive progenitors in the embryonic pancreas at E14.0 and these changes resulted in an increased beta cell fraction in neonates.

CONCLUSIONS/INTERPRETATION

These results indicate that exposure to metformin during gestation modulates the early steps of beta cell development (prior to E14.0) towards an increase in the number of pancreatic and endocrine progenitors. These changes ultimately result in a higher beta cell fraction at birth. These findings are of clinical importance given that metformin is currently used for the treatment of gestational diabetes.

Metformin reduces asymmetric dimethylarginine and prevents hypertension in spontaneously hypertensive rats

Elevated asymmetric dimethylarginine (ADMA) levels and nitric oxide (NO) deficiency are associated with the development of hypertension. Metformin, an antidiabetic agent, is a structural analog of ADMA. We examined whether metformin can prevent the development of hypertension in spontaneously hypertensive rats (SHRs) by restoration of ADMA-NO balance. SHRs and control normotensive Wistar-Kyoto (WKY) rats were assigned to 4 groups (N = 8 for each group): untreated SHRs and WKY rats, metformin-treated SHRs and WKY rats. Metformin-treated rats received metformin 500 mg/kg per day via oral gavage for 8 weeks. All rats were sacrificed at the age of 12 weeks. We found an increase in the blood pressure of SHRs was prevented by metformin. ADMA levels in the plasma and lung were elevated in SHRs, which metformin prevented. Lung dimethylarginine dimethylaminohydrolase (DDAH, ADMA-metabolizing enzyme) activity was lower in SHRs than WKY rats. Next, metformin had no effect on protein arginine methyltransferase 1 (ADMA-synthesizing enzyme), DDAH-1, DDAH-2, NO synthase enzymes, and DDAH activity in the kidney. Moreover, metformin increased the levels of NO in kidney. Conclusively, the observed antihypertensive effect of metformin in SHRs is because of the restoration of the ADMA-NO pathway. Our findings support the consideration of metformin as an antihypertensive agent for diabetic patients with prehypertension.

Impact of metformin on reproductive tissues: an overview from gametogenesis to gestation

Metformin is an oral anti-hyperglycemic drug that acts as an insulin sensitizer in the treatment of diabetes mellitus type 2. It has also been widely used in the treatment of polycystic ovary syndrome (PCOS) and gestational diabetes. This drug has been shown to activate a protein kinase called 5' AMP-activated protein kinase or AMPK. AMPK is present in many tissues making metformin's effect multi factorial. However as metformin crosses the placenta, its use during pregnancy raises concerns regarding potential adverse effects on the mother and fetus. The majority of reports suggest no significant adverse effects or teratogenicity. However, disconcerting reports of male mouse offspring that were exposed to metformin in utero that present with a reduction in testis size, seminiferous tubule size and in Sertoli cell number suggest that we do not understand the full suite of effects of metformin. In addition, recent molecular evidence is suggesting an epigenetic effect of metformin which could explain some of the long-term effects reported. Nevertheless, the data are still insufficient to completely confirm or disprove negative effects of metformin. The aims of this review are to provide a summary of the safety of metformin in various aspects of sexual reproduction, the use of metformin by gestating mothers, and its possible side-effects on offspring from women who are administered metformin during pregnancy.

The effect of exercise and metformin treatment on circulating free DNA in pregnancy

INTRODUCTION

Some pregnancy complications are characterized by increased levels of cell-free fetal (cffDNA) and maternal DNA (cfmDNA), the latter may also be elevated during physical strain. This study aims at assessing the impact of exercise and metformin intervention in pregnancy, and to compare the levels of cell free DNA in pregnant women with or without PCOS diagnosis.

METHODS

Consecutive women from two previous randomized controlled trials in pregnancy were included. Women came from a trial with organized exercise vs. standard antenatal care in pregnancy and a trial of metformin vs. placebo in PCOS women. Levels of cffDNA, cfmDNA and cell-free total DNA (cftDNA) were measured by qPCR.

RESULTS

Training in pregnancy did not affect the levels of cffDNA, cfmDNA or cftDNA. PCOS-women treated with metformin had lower levels of cfmDNA and cftDNA at week 32 (mean ± SD: 301 ± 162 versus 570 ± 337, p = 0.012, 345 ± 173 versus 635 ± 370, p = 0.019); otherwise the levels were comparable to PCOS-controls. Metformin-treated PCOS-women had higher cffDNA at inclusion, in the 1st trimester; later on in pregnancy the levels in the metformin and placebo groups were equal. A comparison of pregnant women in the exercise study (TRIP) to placebo-treated pregnant PCOS-women, showed the levels of cffDNA, cfmDNA or cftDNA during mid-pregnancy (weeks 18-36) to be equal.

DISCUSSION

Training during pregnancy was not associated with altered levels of cffDNA cfmDNA or cftDNA, but metformin treatment may reduce cfmDNA and cftDNA in pregnant PCOS women.

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.

Maternal and fetal insulin levels at birth in women with polycystic ovary syndrome: data from a randomized controlled study on metformin

CONTEXT

Metformin is suggested to reduce pregnancy complications in women with polycystic ovary syndrome (PCOS). Metformin crosses the placenta and therapeutic concentrations are measured in the fetal circulation. Whether metformin treatment in pregnant PCOS women affects maternal and fetal insulin concentrations at birth is not clarified.

OBJECTIVES

To investigate the possible effect of metformin on insulin concentrations in umbilical cord blood and the possible association between maternal and fetal insulin concentrations.

DESIGN

Post-hoc analysis of a subgroup of PCOS women participating in a double-blind randomized controlled trial.

SETTING

University hospital setting.

PARTICIPANTS

Women with PCOS (n=118), aged 19-39 years.

MAIN OUTCOME MEASURES

Maternal and umbilical cord insulin concentrations immediately after birth.

RESULTS

At delivery women randomized to metformin had lower insulin concentrations than those randomized to placebo (259±209 vs 361±261 pmol/l; P=0.020). No difference was found in insulin concentrations in umbilical venous (P=0.95) and arterial (P=0.39) blood between the metformin and placebo groups. The arteriovenous difference was also equal between the groups (P=0.38). Insulin concentrations were higher in the umbilical vein than in the umbilical artery independent of randomization (70±51 vs 45±48 pmol/l; P<0.0005).

CONCLUSIONS

In PCOS, metformin treatment during pregnancy resulted in lower maternal insulin concentrations at delivery. Metformin treatment did not affect fetal insulin concentrations. Higher insulin concentrations in the umbilical vein indicate that the placenta somehow secretes insulin to the fetus. The possibility of placental insulin secretion to the fetus deserves further investigations.

The use of oral hypoglycaemic agents in pregnancy

While insulin has been the treatment of choice when lifestyle measures do not maintain glycaemic control during pregnancy, recent studies have suggested that certain oral hypoglycaemic agents may be safe and acceptable alternatives. With the exception of metformin and glibenclamide (glyburide), there are insufficient data to recommend treatment with any other oral hypoglycaemic agent during pregnancy. There are no serious safety concerns with metformin, despite it crossing the placenta. When used in the first trimester, there is no increase in congenital abnormalities and there appears to be a reduction in miscarriage, pre-eclampsia and subsequent gestational diabetes. Studies of the use of metformin in gestational diabetes show at least equivalent neonatal outcomes, while reporting reductions in neonatal hypoglycaemia, maternal hypoglycaemia and weight gain and improved treatment satisfaction. Glibenclamide effectively lowers blood glucose in women with gestational diabetes, possibly with a lower treatment failure rate than metformin. Although generally well tolerated, some studies have reported higher rates of pre-eclampsia, neonatal jaundice, longer stay in the neonatal care unit, macrosomia and neonatal hypoglycaemia. There is a paucity of long-term follow-up data on children exposed to oral agents in utero. The American College of Obstetrics and Gynecology and the UK National Institute of Health and Care Excellence (NICE) have recommended that either metformin or glibenclamide can be used to treat gestational diabetes. Metformin is also recommended for use in the pre-conception period by NICE. By contrast, the American Diabetes Association recommends that both drugs should only be used during pregnancy in the context of clinical trials.

The efficacy of metformin in pregnant women with polycystic ovary syndrome: a meta-analysis of clinical trials

OBJECTIVES

The role of metformin in the treatment of pregnant women with polycystic ovary syndrome (PCOS) is controversial. Therefore, we evaluated whether the use of metformin during pregnancy in women with PCOS could reduce pregnancy-related complications.

RESEARCH DESIGN AND METHODS

MEDLINE was searched to retrieve relevant trials. In addition, reviews and reference lists of the retrieved articles were scanned for further appropriate studies. The primary outcome measure was the incidence of complications of pregnancy, which included early pregnancy loss (EPL), gestational diabetes (GDM), pre-eclampsia (PE), and pre-term delivery (PD).

RESULTS

In total, eight studies with 1106 patients were included. The pooled odds ratio (OR) (95% confidence interval) of outcome for pregnant women with PCOS prescribed metformin were 0.32 (0.19-0.55) for EPL, 0.37 (0.25-0.56) for GDM, 0.53 (0.30-0.95) for PE and 0.30 (0.13-0.68) for PD.

CONCLUSIONS

Metformin therapy throughout pregnancy decreased the OR of EPL, GDM, PE, and PD in pregnant PCOS women with no serious detrimental side effects.

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.

Effect of type 2 diabetes mellitus on the pharmacokinetics of metformin in obese pregnant women

BACKGROUND AND OBJECTIVE

The use of metformin throughout gestation by women with polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus (T2DM) significantly reduces the number of first-trimester spontaneous abortions and the rate of occurrence of gestational diabetes and hypertensive syndromes. Metformin is taken up into renal tubular cells by organic cation transport 2 (OCT2) and eliminated unchanged into the urine. The objective of this study was to analyse the influence of T2DM on the pharmacokinetics of metformin in obese pregnant women and in a control group of non-diabetic obese pregnant women with PCOS.

METHODS

Eight non-diabetic obese pregnant women with PCOS and nine obese pregnant women with T2DM taking oral metformin 850 mg every 12 h were evaluated throughout gestation. Serial blood samples were collected over a 12-h period during the third trimester of pregnancy. Steady-state plasma concentrations of metformin were determined by high-performance liquid chromatography with a UV detector. The pharmacokinetic results of the two groups, reported as median and 25th and 75th percentile, were compared statistically using the Mann-Whitney test, with the level of significance set at p < 0.05.

RESULTS

The pharmacokinetic parameters detected for PCOS versus T2DM patients, reported as median, were, respectively: elimination half-life 3.75 versus 4.00 h; time to maximum concentration 2.00 versus 3.00 h; maximum concentration 1.42 versus 1.21 μg/mL; mean concentration 0.53 versus 0.56 μg/mL; area under the plasma concentration-time curve from time zero to 12 h 6.42 versus 6.73 μg·h/mL; apparent total oral clearance 105.39 versus 98.38 L/h; apparent volume of distribution after oral administration 550.51 versus 490.98 L; and fluctuation (maximum-minimum concentration variation) of 179.56 versus 181.73 %. No significant differences in pharmacokinetic parameters were observed between the groups.

CONCLUSION

T2DM in the presence of insulin use does not influence the pharmacokinetics of metformin in pregnant patients, demonstrating the absence of a need to increase the dose, and consequently does not influence the OCT2-mediated transport in pregnant women with PCOS.

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.