A cautionary response to SMFM statement: pharmacological treatment of gestational diabetes

A narrative review of metformin in pregnancy: Navigating benefit and uncertainty

Metformin is well-established as a treatment for type 2 diabetes in non-pregnant individuals. The low cost, acceptability and broad tolerability of metformin have also made it an attractive option for research into the treatment of other conditions associated with insulin resistance. Despite almost 50 years of clinical experience with the use of metformin to treat diabetes in pregnancy, many questions remain regarding its precise effectiveness in different maternal subgroups, as well as potential short-term and long-term effects on the offspring. In this narrative review, we present the current evidence for the use of metformin during pregnancy in various maternal subgroups, including women living with overweight and obesity, women at risk of gestational diabetes, women diagnosed with gestational diabetes and women with pregestational diabetes, including type 2 diabetes. Our specific focus is on the impact of metformin on short-term maternal, fetal and neonatal outcomes. We also consider the evidence for other emerging indications for metformin in pregnancy, such as the prevention and management of pre-eclampsia. PLAIN LANGUAGE SUMMARY: This article looks at research on how metformin use in pregnancy affects mothers and newborns in the short term. Doctors have prescribed metformin since the 1970s for the treatment of diabetes in pregnancy. Despite years of use, there are still questions about how safe and effective metformin is for mothers and their children. Metformin taken during pregnancy moves through the placenta into the foetus's bloodstream. The short-term and long-term effects of metformin on offspring need careful attention. The studies that have looked at the link between metformin use and birth defects have not found any strong link between taking metformin in pregnancy and birth defects, however close attention will continue to be paid in this area. Some large studies have examined the use of metformin in pregnant women who do not have diabetes, but who do live with overweight or obesity. The studies are difficult to compare. Some, but not all, of these studies have shown less weight gain for the mother if metformin is taken by these women during pregnancy. Other large studies have looked at whether metformin can prevent gestational diabetes. The results are mostly disappointing. They suggest that metformin does not stop gestational diabetes from developing. However, the participants in these studies were mostly from white backgrounds and metformin may help prevent gestational diabetes in women of different ethnic backgrounds. However, more research is needed. Metformin has been widely studied as an alternative to insulin for the treatment of gestational diabetes. Because different countries diagnose and treat GDM differently, this makes comparing study results difficult. Women with gestational diabetes seem to gain less weight during pregnancy if they use metformin rather than insulin. Using metformin instead of insulin may result in lower average birth weights for babies from these pregnancies. Also, the use of metformin may lead to fewer babies being born abnormally large. Similarly, large trials have examined the use of metformin in pregnant women who are living with type 2 diabetes. These studies show that metformin can lower a mother's insulin needs. It can also help control weight gain and reduce the risk of having a large baby. One study found that metformin use in women living with Type 2 diabetes might increase the risk of having smaller babies. This was especially true if the mother had high blood pressure or kidney disease. This finding requires further investigation. Metformin might help prevent pre-eclampsia, but this is still unclear. Research is ongoing into a potential role for metformin in the treatment of pre-eclampsia. In conclusion, metformin has been studied in many groups of pregnant women. Women with gestational diabetes or type 2 diabetes may see benefits like less weight gain and better blood sugar/glucose control. Current evidence suggests that metformin shouldn't be used if there are foetal growth issues. It is also not recommended for mothers with high blood pressure or kidney disease. Future studies might find specific groups of pregnant women who would benefit the most from metformin.

Effect of in utero metformin exposure in gestational diabetes mellitus on infant mesenchymal stem cell metabolism

Offspring exposed to metformin treatment for gestational diabetes mellitus (GDM) experience altered growth patterns that increase the risk for developing cardiometabolic diseases later in life. The adaptive cellular mechanisms underlying these patterns remain unclear. Therefore, the objective of this study was to determine whether chronic in utero metformin exposure associated with GDM treatment elicits infant cellular metabolic adaptations. In a cross-sectional design, 22 pregnant women diagnosed with GDM and treated exclusively with metformin (Met; n = 12) or diet (A1DM; n = 10) were compared. Umbilical cord-derived mesenchymal stem cells (MSCs) were used as a model to study infant metabolism in vitro. OXPHOS and citrate synthase content were assessed by Western blot and intracellular lipid content was measured by Oil Red-O staining. Substrate oxidation and insulin action were measured with 14C radiolabeled glucose and oleate at baseline and following a 24-h lipid challenge. Mitochondrial respiration was assessed by high-resolution respirometry. Although no differences in infant birth measures were observed between groups, MSC outcomes revealed lower oleate oxidation rates (P = 0.03) and lower mitochondrial capacity (P = 0.009) among Met-MSCs. These findings suggest differences in energy metabolism may be present at birth among offspring exposed to metformin in utero. Lower oleate oxidation and mitochondrial capacity in infant MSC may contribute to altered growth patterns that have been reported among offspring of metformin-treated pregnant women with GDM.NEW & NOTEWORTHY Mesenchymal stem cells (MSCs) of infants born to women with gestational diabetes mellitus (GDM) treated by metformin display lower rates of oleate oxidation despite no limitations in lipid availability compared with GDM treated by diet. Mitochondrial capacity was also lower among infant MSCs from metformin-treated GDM.

Navigating Diabetes in Pregnancy: Critical Approaches to Mitigate Risks and Improve Outcomes for Mother and Child

With the increasing prevalence of diabetes and its growing impact on maternal and fetal health, management during pregnancy has become critical. This review describes the pathophysiology of insulin resistance during pregnancy, adverse outcomes correlated with diabetic pregnancies, and current management strategies. We investigate two leading approaches to managing pregnant patients with diabetes-lifestyle intervention and drug treatment. Lifestyle intervention, including dietary counseling, exercise regimens, patient education, and self-administered blood glucose monitoring, has demonstrated promising results in the management and prevention of gestational diabetes mellitus (GDM). Early intervention and treatment of at-risk patients have been critical for positive outcomes. Drug treatment, focusing on the utilization of insulin, insulin analogs, and antihyperglycemic agents has shown efficacy in achieving glycemic control and improving maternal and neonatal outcomes. These findings indicate that a combination of early lifestyle intervention and targeted drug treatment yields the most benefit in managing diabetes in pregnancy. To augment treatment, continuous glucose monitoring and telemedicine have become valuable tools in managing diabetes during pregnancy. Future research should aim to develop more effective antihyperglycemic agents, improve telehealth accessibility, and enhance preconception care for women at risk of developing GDM. By addressing these areas, we can significantly reduce the adverse outcomes associated with diabetes in pregnancy and improve overall maternal and fetal health.

Metformin in gestational diabetes: physiological actions and clinical applications

Metformin is an effective oral hypoglycaemic agent used in the treatment of type 2 diabetes mellitus; however, its use in pregnancy for the treatment of gestational diabetes mellitus (GDM) remains controversial owing to concerns around safety and efficacy. This comprehensive review outlines the physiological metabolic functions of metformin and synthesizes existing literature and key knowledge gaps pertaining to the use of metformin in pregnancy across various end points in women with GDM. On the basis of current evidence, metformin reduces gestational weight gain, neonatal hypoglycaemia and macrosomia and increases insulin sensitivity. However, considerable heterogeneity between existing studies and the grouping of aggregate and often inharmonious data within meta-analyses has led to disparate findings regarding the efficacy of metformin in treating hyperglycaemia in GDM. Innovative analytical approaches with stratification by individual-level characteristics (for example, obesity, ethnicity, GDM severity and so on) and treatment regimens (diagnostic criteria, treatment timing and follow-up duration) are needed to establish efficacy across a range of end points and to identify which, if any, subgroups might benefit from metformin treatment during pregnancy.

Metformin and risk of adverse pregnancy outcomes among pregnant women with gestational diabetes in the United Kingdom: A population-based cohort study

AIMS

Metformin is increasingly used off-label as the treatment of gestational diabetes (GDM). Our objective was to determine if metformin versus insulin initiation is associated with the adverse pregnancy outcomes.

MATERIALS AND METHODS

We conducted a retrospective cohort study using data from the Clinical Practice Research Datalink, its pregnancy register, and Hospital Episode Statistics from 1998 to 2018. We included pregnancies of women who initiated metformin or insulin between 20 weeks gestation and pregnancy end. The primary outcome was a composite outcome of large for gestational age (LGA) and macrosomia. The secondary outcomes included small for gestational age (SGA), preterm birth, caesarean delivery, and hypertensive disorders during pregnancy (HDP). Inverse probability weighted-Cox proportional hazards models were to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CI), comparing those who initiated metformin versus insulin at cohort entry, accounting for baseline covariates.

RESULTS

Our cohort included pregnancies of 1297 women initiating metformin and of 895 women initiating insulin. Compared to insulin initiation, metformin initiation was associated with a decreased risk of LGA or macrosomia (HR 0.64, 95% CI 0.49, 0.78), Caesarean delivery (HR 0.83, 95% CI 0.69, 0.98), and preterm birth (HR 0.83, 95% CI 0.58, 1.08). The HRs for HDP and SGA were 0.92 (95% CI 0.57, 1.27) and 1.33 (95% CI 0.67, 2.00), respectively.

CONCLUSIONS

Our study suggests that, compared to initiating insulin, initiating metformin is associated with decreased risks of adverse pregnancy outcomes among women with GDM. These findings provide important real-world evidence regarding the use of metformin for GDM.

Glucagon-like peptide-1 receptor agonist use in pregnancy: a review

Glucagon-like peptide-1 receptor agonists are peptide analogues that are used to treat type 2 diabetes mellitus and obesity. The first medication in this class, exenatide, was approved in 2005, and these medications, specifically semaglutide, have become more popular in recent years due to their pronounced effects on glycemic control, weight reduction, and cardiovascular health. Due to successful weight loss from these medications, many women previously diagnosed with oligomenorrhea and unable to conceive have experienced unplanned pregnancies while taking the medications. However, there are currently little data for clinicians to use in counseling patients in cases of accidental periconceptional exposure. In some studies examining small animals exposed to glucagon-like peptide-1 receptor agonists in pregnancy, there has been evidence of adverse outcomes in the offspring, including decreased fetal growth, skeletal and visceral anomalies, and embryonic death. Although there are no prospective studies in humans, case reports, cohort studies, and population-based studies have not shown a pattern of congenital anomalies in infants. A recent large, observational, population-based cohort study examined 938 pregnancies affected by type 2 diabetes mellitus and compared outcomes from periconceptional exposure to glucagon-like peptide-1 receptor agonists and insulin. The authors concluded there was not a significantly increased risk of major congenital malformations in patients taking glucagon-like peptide-1 receptor agonists, although there was no information on maternal glycemic control or diabetic fetopathy. As diabetic embryopathy is directly related to the degree of maternal hyperglycemia and not the diagnosis of diabetes itself, it is not possible to make this conclusion without this information. Furthermore, there is little evidence available regarding fetal growth restriction, embryonic or fetal death, or other potential complications. At this time, patients should be counseled there is not enough evidence to predict any adverse effects, or the lack thereof, of periconceptional exposure of glucagon-like peptide-1 receptor agonists during pregnancy. We recommend that all patients use contraception to prevent unintended pregnancy while taking glucagon-like peptide-1 receptor agonists.

American Diabetes Association Professional Practice Committee, ElSayed NA, McCoy RG, Aleppo G, Balapattabi K, Beverly EA, Briggs Early K, Bruemmer D, Echouffo-Tcheugui JB, Ekhlaspour L, Garg R, Khunti K, Lal R, Lingvay I, Matfin G, Pandya N, Pekas EJ, Pilla SJ, Polsky S, Segal AR, Seley JJ, Stanton RC, Bannuru RR. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2025

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

A meta-analysis of metformin and insulin on maternal outcome and neonatal outcome in patients with gestational diabetes mellitus

INTRODUCTION

The use of metformin for treating gestational diabetes mellitus (GDM) remains controversial because it can pass through the placenta. This meta-analysis aimed to compare the effects of metformin and insulin on maternal and neonatal outcomes in patients with GDM.

METHODS

We conducted a comprehensive search of the PubMed, Embase, and Cochrane Library databases, focusing on randomized controlled trials (RCTs) that evaluated the impacts of metformin and insulin on both maternal and neonatal outcomes in patients with GDM.

RESULTS

Twenty-four RCTs involving 4934 patients with GDM were included in this meta-analysis. Compared with insulin, metformin demonstrated a significant reduction in the risks of preeclampsia (RR 0.61, 95% CI 0.48 to 0.78, p < .0001), induction of labor (RR 0.90, 95% CI 0.82 to 0.98, p = .02), cesarean delivery (RR 0.91, 95% CI 0.85 to 0.98, p = .01), macrosomia (RR 0.67, 95% CI 0.53 to 0.83, p = .0004), neonatal intensive care unit (NICU) admission (RR 0.75, 95% CI 0.66 to 0.86, p < .0001), neonatal hypoglycemia (RR 0.55, 95% CI 0.48 to 0.63, p < .00001), and large for gestational age (LGA) (RR 0.80, 95% CI 0.68 to 0.94, p = .007). Conversely, metformin showed no significant impact on gestational hypertension (RR 0.84, 95% CI 0.67 to 1.06, p = .15), spontaneous vaginal delivery (RR 1.13, 95% CI 1.00 to 1.08, p = .05), emergency cesarean section (RR 0.94, 95% CI 0.77 to 1.16, p = .58), shoulder dystocia (RR 0.65, 95% CI 0.31 to 1.39, p = .27), premature birth (RR 0. 92, 95% CI 0.61 to 1.39, p = .69), polyhydramnios (RR 1.11, 95% CI 0.54 to 2.30, p = .77), birth trauma (RR 0.87, 95% CI 0.54 to 1.39, p = .56), 5-min Apgar score < 7 (RR 1.13, 95% CI 0.76 to 1.68, p = .55), small for gestational age (SGA) (RR 0.93, 95% CI 0.71 to 1.22, p = .62), respiratory distress syndrome (RDS) (RR 0.74, 95% CI 0.50 to 1.08, p = .11), jaundice (RR 1.09, 95% CI 0.95 to 1.25, p = .24) or birth defects (RR 0.80, 95% CI 0.37 to 1.74, p = .57).

CONCLUSIONS

The findings suggest that metformin can reduce the risk of certain maternal and neonatal outcomes compared with insulin therapy for GDM. However, long-term follow-up studies of patients with GDM taking metformin and their offspring are warranted to provide further evidence.

Insulin Management for Gestational and Type 2 Diabetes in Pregnancy

Insulin is preferred as the first-line agent for glucose management of gestational diabetes mellitus and type 2 diabetes in pregnancy when nutritional and lifestyle modifications are unable to achieve pregnancy-specific glucose targets. Individual heterogeneity in defects of insulin secretion or sensitivity in liver and muscle, unique genetic influences on pregnancy glycemic regulation, and variable cultural and lifestyle behaviors that affect meal, activity, sleep, and occupational schedules necessitate a personalized approach to insulin regimens. Newer insulin preparations have been developed to mimic the physiologic release of endogenous insulin, maintaining appropriate basal levels to cover hepatic gluconeogenesis and simulate the rapid, meal-related, bolus rise of insulin. Such physiologic basal-bolus dosing of insulin can be administered safely, achieving tighter glycemic control while reducing episodes of hypoglycemia. Insulin initiation and titration require understanding the pharmacodynamics of different insulin preparations in addition to a patient's glycemic profiles, effect of variable nutritional intake and mealtimes, physical activity, stress, timing of sleep cycles, and cultural habits. Educating and empowering patients to learn how their glucose responds to insulin, portion and content of meals, and physical activity can increase personal engagement in therapy, flexibility in eating patterns, and improved glycemic control. This Clinical Expert Series article is focused on optimizing insulin management (initiation, dosing, and titration) of gestational and type 2 diabetes in pregnancy.

Primary Care for Gestational Diabetes: A Bibliometric Analysis of Publications from 1991 to 2024

Gestational diabetes mellitus (GDM) represents a significant medical complication during pregnancy, with a global prevalence ranging from 2% to 26% and increasing by over 30% in recent decades. Therefore, the aim of our study is to assess the trends and distribution of published studies, as well as the contributions of countries, institutions, journals, and authors to the development of primary care for pregnant women with gestational diabetes. In this bibliometric analysis, we examine the role of primary health care in GDM from 1991 to 2024. The data were sourced from Scopus and Web of Science, encompassing 276 articles from 150 sources and involving 1375 authors. The analysis reveals a steady increase in publications, with a 4.29% annual growth rate. This study identifies the USA and UK as leading countries in GDM research, and there are significant international collaborations, with the USA having 17 joint articles with other countries. The University of Eastern Finland, Ohio State University, and Harvard University are noted as the most prolific institutions, with 23, 17, and 16 articles, respectively. Additionally, the journal Diabetes Care published the highest number of articles, totaling 635. Prominent authors such as Bernstein J. and McCloskey L., with seven articles each, have made substantial contributions to the field. Our work highlights the need to pay special attention to primary care for gestational diabetes, as many negative consequences of the disease can be prevented at this stage. Innovative approaches to screening for GDM can significantly improve treatment outcomes and reduce health risks, which will have long-term positive effects both for individual patients and society as a whole.

Position statement of Italian Society of Obesity (SIO): Gestational Obesity

PURPOSE

Gestational obesity (GO) presents a multifaceted challenge to maternal and fetal health, with an escalating prevalence and far-reaching consequences extending beyond pregnancy. This perspective statement by the Italian Society of Obesity (SIO) provides current insights into the diagnosis, maternal and fetal impacts, and treatment strategies for managing this pressing condition.

METHODS

This article provides a comprehensive review of the maternal and fetal effects of GO and provides suggestions on strategies for management. Comprehensive review was carried out using the MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library databases.

RESULTS

The diagnosis of GO primarily relies on pre-pregnancy body mass index (BMI), although standardized criteria remain contentious. Anthropometric measures and body composition assessments offer valuable insights into the metabolic implications of GO. Women with GO are predisposed to several health complications, which are attributed to mechanisms such as inflammation and insulin resistance. Offspring of women with GO face heightened risks of perinatal complications and long-term metabolic disorders, indicating intergenerational transmission of obesity-related effects. While nutritional interventions are a cornerstone of management, their efficacy in mitigating complications warrants further investigation. Additionally, while pharmacological interventions have been explored in other contexts, evidence on their safety and efficacy specifically for GO remains lacking, necessitating further investigation.

CONCLUSION

GO significantly impacts maternal and fetal health, contributing to both immediate and long-term complications. Effective management requires a multifaceted approach, including precise diagnostic criteria, personalized nutritional interventions, and potential pharmacological treatments. These findings underscore the need for individualized care strategies and further research to optimize outcomes for mothers and their offspring are needed. Enhanced understanding and management of GO can help mitigate its intergenerational effects, improving public health outcomes.

LEVEL OF EVIDENCE

Level V narrative review.

Comparative effectiveness trial of metformin versus insulin for the treatment of gestational diabetes in the USA: clinical trial protocol for the multicentre DECIDE study

INTRODUCTION

Gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy. Glycaemic control decreases the risk of adverse pregnancy outcomes for the affected pregnant individual and the infant exposed in utero. One in four individuals with GDM will require pharmacotherapy to achieve glycaemic control. Injectable insulin has been the mainstay of pharmacotherapy. Oral metformin is an alternative option increasingly used in clinical practice. Both insulin and metformin reduce the risk of adverse pregnancy outcomes, but comparative effectiveness data from a well-characterised, adequately powered study of a diverse US population remain lacking. Because metformin crosses the placenta, long-term safety data, in particular, the risk of childhood obesity, from exposed children are also needed. In addition, the patient-reported experiences of individuals with GDM requiring pharmacotherapy remain to be characterised, including barriers to and facilitators of metformin versus insulin use.

METHODS AND ANALYSIS

In a two-arm open-label, pragmatic comparative effectiveness randomised controlled trial, we will determine if metformin is not inferior to insulin in reducing adverse pregnancy outcomes, is comparably safe for exposed individuals and children, and if patient-reported factors, including facilitators of and barriers to use, differ between metformin and insulin. We plan to recruit 1572 pregnant individuals with GDM who need pharmacotherapy at 20 US sites using consistent diagnostic and treatment criteria for oral metformin versus injectable insulin and follow them and their children through delivery to 2 years post partum. More information is available at www.decidestudy.org.

ETHICS AND DISSEMINATION

The Institutional Review Board at The Ohio State University approved this study (IRB: 2024H0193; date: 7 December 2024). We plan to submit manuscripts describing the results of each study aim, including the pregnancy outcomes, the 2-year follow-up outcomes, and mixed-methods assessment of patient experiences for publication in peer-reviewed journals and presentations at international scientific meetings.

TRIAL REGISTRATION NUMBER

NCT06445946.

Initiation of metformin in early pregnancy results in fetal bioaccumulation, growth restriction, and renal dysmorphology in a primate model

BACKGROUND

In recent years, pragmatic metformin use in pregnancy has stretched to include prediabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and (most recently) preeclampsia. However, with its expanded use, concerns of unintended harm have been raised.

OBJECTIVE

This study developed an experimental primate model and applied ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry for direct quantitation of maternal and fetal tissue metformin levels with detailed fetal biometry and histopathology.

STUDY DESIGN

Within 30 days of confirmed conception (defined as early pregnancy), 13 time-bred (timed-mated breeding) Rhesus dams with pregnancies designated for fetal necropsy were initiated on twice-daily human dose-equivalent 10 mg/kg metformin or vehicle control. Pregnant dams were maintained as pairs and fed either a control chow or 36% fat Western-style diet. Metformin or placebo vehicle control was delivered in various treats while the animals were separated via a slide. A cesarean delivery was performed at gestational day 145, and amniotic fluid and blood were collected, and the fetus and placenta were delivered. The fetus was immediately necropsied by trained primate center personnel. All fetal organs were dissected, measured, sectioned, and processed per clinical standards. Fluid and tissue metformin levels were assayed using validated ultrahigh performance liquid chromatography coupled to triple-quadrupole mass spectrometry in selected reaction monitoring against standard curves.

RESULTS

Among 13 pregnancies at gestational day 145 with fetal necropsy, 1 dam and its fetal tissues had detectable metformin levels despite being allocated to the vehicle control group (>1 μmol metformin/kg maternal weight or fetal or placental tissue), whereas a second fetus allocated to the vehicle control group had severe fetal growth restriction (birthweight of 248.32 g [<1%]) and was suspected of having a fetal congenital condition. After excluding these 2 fetal pregnancies from further analyses, 11 fetuses from dams initiated on either vehicle control (n=4: 3 female and 1 male fetuses) or 10 mg/kg metformin (n=7: 5 female and 2 male fetuses) were available for analyses. Among dams initiated on metformin at gestational day 30 (regardless of maternal diet), significant bioaccumulation within the fetal kidney (0.78-6.06 μmol/kg; mean of 2.48 μmol/kg), liver (0.16-0.73 μmol/kg; mean of 0.38 μmol/kg), fetal gut (0.28-1.22 μmol/kg; mean of 0.70 μmol/kg), amniotic fluid (0.43-3.33 μmol/L; mean of 1.88 μmol/L), placenta (0.16-1.00 μmol/kg; mean of 0.50 μmol/kg), fetal serum (0.00-0.66 μmol/L; mean of 0.23 μmol/L), and fetal urine (4.10-174.10 μmol/L; mean of 38.5 μmol/L) was observed, with fetal levels near biomolar equivalent to maternal levels (maternal serum: 0.18-0.86 μmol/L [mean of 0.46 μmol/L]; maternal urine: 42.60-254.00 μmol/L [mean of 149.30 μmol/L]). Western-style diet feeding neither accelerated nor reduced metformin bioaccumulations in maternal or fetal serum, urine, amniotic fluid, placenta, or fetal tissues. In these 11 animals, fetal bioaccumulation of metformin was associated with less fetal skeletal muscle (57% lower cross-sectional area of gastrocnemius) and decreased liver, heart, and retroperitoneal fat masses (P<.05), collectively driving lower delivery weight (P<.0001) without changing the crown-rump length. Sagittal sections of fetal kidneys demonstrated delayed maturation, with disorganized glomerular generations and increased cortical thickness. This renal dysmorphology was not accompanied by structural or functional changes indicative of renal insufficiency.

CONCLUSION

Our study demonstrates fetal bioaccumulation of metformin with associated fetal growth restriction and renal dysmorphology after maternal initiation of the drug within 30 days of conception in primates. Given these results and the prevalence of metformin use during pregnancy, additional investigation of any potential immediate and enduring effects of prenatal metformin use is warranted.

Patient Priorities, Decisional Comfort, and Satisfaction with Metformin versus Insulin for the Treatment of Gestational Diabetes Mellitus

OBJECTIVE

 We compared patient priorities, decisional comfort, and satisfaction with treating gestational diabetes mellitus (GDM) with metformin versus insulin among pregnant individuals with GDM requiring pharmacotherapy.

STUDY DESIGN

 We conducted a cross-sectional study of patients' perspectives about GDM pharmacotherapy in an integrated prenatal and diabetes care program from October 19, 2022, to August 24, 2023. The exposure was metformin versus insulin as the initial medication decision. Outcomes included standardized measures of patient priorities, decisional comfort, and satisfaction about their medication decision.

RESULTS

 Among 144 assessed individuals, 60.4% were prescribed metformin and 39.6% were prescribed insulin. Minoritized individuals were more likely to receive metformin compared with non-Hispanic White individuals (34.9 vs. 17.5%; p = 0.03). Individuals who were willing to participate in a GDM pharmacotherapy clinical trial were more likely to receive insulin than those who were unwilling (30.4 vs. 19.5%; p = 0.02). Individuals receiving metformin were more likely to report prioritizing avoiding injections (62.4 vs. 19.3%; adjusted odds ratio [aOR]: 2.83; 95% confidence interval [CI]: 1.10-7.31), wanting to take a medication no more than twice daily (56.0 vs. 30.4%; aOR: 3.67; 95% CI: 1.56-8.67), and believing that both medications can equally prevent adverse pregnancy outcomes (70.9 vs. 52.6%; aOR: 2.67; 95% CI: 1.19-6.03). Conversely, they were less likely to report prioritizing a medication that crosses the placenta (39.1 vs. 82.5%; aOR: 0.09; 95% CI: 0.03-0.25) and needing supplemental insulin to achieve glycemic control (21.2 vs. 47.4%; aOR: 0.36; 95% CI: 0.15-0.90). Individuals reported similarly high (mean score > 80%) levels of decisional comfort, personal satisfaction with medication decision-making, and satisfaction about their conversation with their provider about their medication decision with metformin and insulin (p ≥ 0.05 for all).

CONCLUSION

 Individuals with GDM requiring pharmacotherapy reported high levels of decision comfort and satisfaction with both metformin and insulin, although they expressed different priorities in medication decision-making. These results can inform future patient-centered GDM treatment strategies.

KEY POINTS

· Pregnant individuals with GDM requiring pharmacotherapy expressed a high level of decisional comfort and satisfaction with medication decision making.. · Individuals placed different priorities on deciding to take metformin versus insulin.. · These results can inform interventions aimed at delivering person-centered diabetes care in pregnancy that integrates patient autonomy and knowledge about treatment options..

One-step vs 2-step gestational diabetes mellitus screening and pregnancy outcomes: an updated systematic review and meta-analysis

OBJECTIVE

This was a systematic review and meta-analysis comparing maternal and neonatal outcomes of patients screened with the 1-step or 2-step screening method for gestational diabetes mellitus.

DATA SOURCES

PubMed, Scopus, Cochrane, ClinicalTrials.gov, and LILACS were searched from inception up to September 2022.

STUDY ELIGIBILITY CRITERIA

Only randomized controlled trials were included. Studies that had overlapping populations were excluded (International Prospective Register of Systematic Review registration number: CRD42022358903).

METHODS

Risk ratios were computed with 95% confidence intervals by 2 authors. Unpublished data were requested. Large for gestational age was the primary outcome.

RESULTS

The search yielded 394 citations. Moreover, 7 randomized controlled trials met the inclusion criteria. A total of 54,650 participants were screened for gestational diabetes mellitus by either the 1-step screening method (n=27,163) or the 2-step screening method (n=27,487). For large for gestational age, there was no significant difference found between the groups (risk ratio, 0.99; 95% confidence interval, 0.93-1.05; I2=0%). Newborns of patients who underwent 1-step screening had higher rates of neonatal hypoglycemia (risk ratio, 1.24; 95% confidence interval, 1.14-1.34; I2=0%) and neonatal intensive care unit admissions (risk ratio, 1.13; 95% confidence interval, 1.04-1.21; I2=0%) than newborns of patients who underwent 2-step screening. Patients in the 1-step screening method group were more likely to be diagnosed with gestational diabetes mellitus (risk ratio, 1.73; 95% confidence interval, 1.44-2.09; I2=80%) than patients in the 2-step screening method group. In addition, among trials that tested all patients before randomization and excluded patients with pregestational diabetes mellitus, newborns were more likely to have macrosomia (risk ratio, 1.27; 95% confidence interval, 1.21-1.34; I2=0%). Overall risk of bias assessment was of low concern.

CONCLUSION

Large for gestational age did not differ between patients screened using the 1-step screening method and those screened using the 2-step screening method. However, patients randomized to the 1-step screening method had higher rates of neonatal hypoglycemia and neonatal intensive care unit admission and maternal gestational diabetes mellitus diagnosis than the patients randomized to the 2-step screening method.

Genetic and inflammatory factors underlying gestational diabetes mellitus: a review

Gestational diabetes mellitus (GDM) poses a significant global health concern, impacting both maternal and fetal well-being. Early detection and treatment are imperative to mitigate adverse outcomes during pregnancy. This review delves into the pivotal role of insulin function and the influence of genetic variants, including SLC30A8, CDKAL1, TCF7L2, IRS1, and GCK, in GDM development. These genetic variations affect beta-cell function and insulin activity in crucial tissues, such as muscle, disrupting glucose regulation during pregnancy. We propose a hypothesis that this variation may disrupt zinc transport, consequently impairing insulin production and secretion, thereby contributing to GDM onset. Furthermore, we discussed the involvement of inflammatory pathways, such as TNF-alpha and IL-6, in predisposing individuals to GDM. Genetic modulation of these pathways may exacerbate glucose metabolism dysregulation observed in GDM patients. We also discussed how GDM affects cardiovascular disease (CVD) through a direct correlation between pregnancy and cardiometabolic function, increasing atherosclerosis, decreased vascular function, dyslipidemia, and hypertension in women with GDM history. However, further research is imperative to unravel the intricate interplay between inflammatory pathways, genetics, and GDM. This understanding is pivotal for devising targeted gene therapies and pharmacological interventions to rectify genetic variations in SLC30A8, CDKAL1, TCF7L2, IRS1, GCK, and other pertinent genes. Ultimately, this review offers insights into the pathophysiological mechanisms of GDM, providing a foundation for developing strategies to mitigate its impact.

Translation of mechanistic advances in preeclampsia to the clinic: Long and winding road

As one of the leading causes of premature birth and maternal and infant mortality worldwide, preeclampsia remains a major unmet public health challenge. Preeclampsia and related hypertensive disorders of pregnancy are estimated to cause >75 000 maternal and 500 000 infant deaths globally each year. Because of rising rates of risk factors such as obesity, in vitro fertilization and advanced maternal age, the incidence of preeclampsia is going up with rates ranging from 5% to 10% of all pregnancies worldwide. A major discovery in the field was the realization that the clinical phenotypes related to preeclampsia, such as hypertension, proteinuria, and other adverse maternal/fetal events, are due to excess circulating soluble fms-like tyrosine kinase-1 (sFlt-1, also referred to as sVEGFR-1). sFlt-1 is an endogenous anti-angiogenic protein that is made by the placenta and acts by neutralizing the pro-angiogenic proteins vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). During the last decade, this work has spawned a new era of molecular diagnostics for early detection of this condition. Antagonizing sFlt-1 either by reducing production or blocking its actions has shown salutary effects in animal models. Further, in early-stage human studies, the therapeutic removal of sFlt-1 from maternal circulation has shown promise in delaying disease progression and improving outcomes. Recently, the FDA approved the first molecular test for preterm preeclampsia (sFlt-1/PlGF ratio) for clinical use in the United States. Measuring serum sFlt-1/PlGF ratio in the acute hospital setting may aid short-term management, particularly regarding step-up or step-down of care, decision to transfer to settings better equipped to manage both the mother and the preterm neonate, appropriate timing of administration of steroids and magnesium sulfate, and in expectant management decisions. The test itself has the potential to save lives. Furthermore, the availability of a molecular test that correlates with adverse outcomes has set the stage for interventional clinical trials testing treatments for this disorder. In this review, we will discuss the role of circulating sFlt-1 and related factors in the pathogenesis of preeclampsia and specifically how this discovery is leading to concrete advances in the care of women with preeclampsia.

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.

Extensive therapeutic effects, underlying molecular mechanisms and disease treatment prediction of Metformin: a systematic review

Metformin (Met), a first-line management for type 2 diabetes mellitus, has been expansively employed and studied with results indicating its therapeutic potential extending beyond glycemic control. Beyond its established role, this therapeutic drug demonstrates a broad spectrum of action encompassing over 60 disorders, encompassing metabolic conditions, inflammatory disorders, carcinomas, cardiovascular diseases, and cerebrovascular pathologies. There is clear evidence of Met's action targeting specific nodes in the molecular pathways of these diseases and, intriguingly, interactions with the intestinal microbiota and epigenetic processes have been explored. Furthermore, novel Met derivatives with structural modifications tailored to diverse diseases have been synthesized and assessed. This manuscript proffers a comprehensive thematic review of the diseases amenable to Met treatment, elucidates their molecular mechanisms, and employs informatics technology to prospect future therapeutic applications of Met. These data and insights gleaned considerably contribute to enriching our understanding and appreciation of Met's far-reaching clinical potential and therapeutic applicability.

American Diabetes Association Professional Practice Committee, ElSayed NA, Aleppo G, Bannuru RR, Bruemmer D, Collins BS, Ekhlaspour L, Hilliard ME, Johnson EL, Khunti K, Lingvay I, Matfin G, McCoy RG, Perry ML, Pilla SJ, Polsky S, Prahalad P, Pratley RE, Segal AR, Seley JJ, Stanton RC, Gabbay RA. 15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

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

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

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.

Achievement of Target Glycemic Goal with Simple Basal Insulin Regimen in Women with Gestational Diabetes: A Prospective Cohort Study

There is little evidence concerning the need to treat gestational diabetes (GDM) in the same way as pregestational diabetes. We evaluated the efficacy of the simple insulin injection (SII) regimen for achieving the target glucose goal without increasing adverse perinatal outcomes in singleton pregnant women with GDM. All subjects underwent self-monitoring of blood glucose (SMBG), and insulin therapy was indicated according to the SMBG profile. Insulin was initially started with the SII regimen, in which one daily injection of NPH insulin before breakfast was used, and another NPH injection was added at bedtime, if necessary. We used the target glucose as <95 mg/dL at fasting and <120 mg/dL postprandial and accepted <130 mg/dL for the latter. If the target glucose did not reach with the regimen, we switched to the multiple daily injection (MDI) with additional prandial insulin aspart. We compared the SMBG profile before delivery as well as the perinatal outcomes between the SII and MDI groups. Among 361 women (age 33.7 years, nullipara 41%, prepregnancy body mass index 23.2 kg/m²) with GDM, 59%, 18%, and 23% were in the diet-alone, SII, and MDI groups, respectively. Consequently, regarding women requiring insulin therapy, 43% were treated with the SII regimen throughout pregnancy. The severity of baseline hyperglycemia according to the SMBG data at baseline was the MDI>the SII>the diet group. The rate of achieving target glucose levels before delivery in the SII group at fasting, postprandial < 120 mg/dL and <130 mg/dL were 93%, 54% and 87%, respectively, which were similar to that in the MDI group (93%, 57%, and 93%, respectively), with no significant differences in perinatal outcomes. In conclusion, more than 40% of women with GDM requiring insulin therapy achieved the target glucose goal with this simple insulin regimen without any increase in adverse effects.

Novel therapeutic and diagnostic approaches for preeclampsia

PURPOSE OF REVIEW

This review will summarize recent findings relating to the diagnostic approach to preeclampsia and current avenues of research aimed at modifying the underlying disease process.

RECENT FINDINGS

Growing international consensus supports a broad preeclampsia definition that incorporates maternal end-organ and uteroplacental dysfunction. Recent evidence demonstrates that this definition better identifies women and babies at risk of adverse outcomes compared to the traditional definition of hypertension and proteinuria. Multiple studies have demonstrated the usefulness and cost-effectiveness of angiogenic biomarkers such as soluble fms-like tyrosine kinase-1 and placental growth factor as a clinical adjunct to diagnose and predict severity of preeclampsia associated outcomes. Current novel therapeutic approaches to preeclampsia target pathogenic pathways (e.g. antiangiogenesis) or downstream effects such as oxidative stress and nitric oxide. Recent findings relating to these promising candidates are discussed. Multicenter clinical trials are needed to evaluate their effectiveness and ability to improve fetal and maternal outcomes.

SUMMARY

We provide an updated framework of the current approaches to define and diagnose preeclampsia. Disease modifying therapies (in particular, targeting the angiogenic pathway) are being developed for the first time and promise to revolutionize the way we manage preeclampsia.

Medications for Managing Preexisting and Gestational Diabetes in Pregnancy

Persons with gestational and pregestational diabetes during pregnancy may require pharmacologic agents to achieve pregnancy glycemic targets, and the available medications for use in pregnancy are limited. Insulin is the only FDA-approved medication for use in pregnancy and has the greatest evidence for safety and efficacy. Metformin and glyburide are the most commonly used oral agents in pregnancy. Understanding each medication's unique pharmacokinetics, potential side effects, fetal or childhood risks, gestational age of medication initiation and patient's diabetes care barriers are important aspects of shared decision-making and choosing a regimen that will achieve glycemic and pregnancy goals.

15. Management of Diabetes in Pregnancy: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

TRIAL REGISTRATION

ClinicalTrials.gov NCT04407650.

Metformin in obese pregnancy has no adverse effects on cardiovascular risk in early childhood

Metformin is widely used in pregnancy, despite lack of long-term safety for children. We hypothesised that metformin exposure in utero is associated with increased cardiovascular risk. We tested this hypothesis in a follow-up study of children born to obese mothers who had participated in a randomised controlled trial of metformin versus placebo in pregnancy (EMPOWaR). We measured body composition, peripheral blood pressure (BP), arterial pulse wave velocity and central haemodynamics (central BP and augmentation index) using an oscillometric device in 40 children of mean (SD) age 5.78 (0.93) years, exposed to metformin (n = 19) or placebo (n = 21) in utero. There were no differences in any of the anthropometric or vascular measures between metformin and placebo-exposed groups in univariate analyses, or after adjustment for potential confounders including the child's behaviour, diet and activity levels. Post-hoc sample size calculation indicated we would have detected large clinically significant differences between the groups but would need an unfeasible large number to detect possible subtle differences in key cardiovascular risk parameters in children at this age of follow-up. Our findings suggest no evidence of increased cardiovascular risk in children born to obese mothers who took metformin in pregnancy and increase available knowledge of the long-term safety of metformin on childhood outcomes.

Association of Glyburide and Subcutaneous Insulin With Perinatal Complications Among Women With Gestational Diabetes

IMPORTANCE

Nearly 30% of individuals with gestational diabetes (GDM) do not achieve glycemic control with lifestyle modification alone and require medication treatment. Oral agents, such as glyburide, have several advantages over insulin for the treatment of GDM, including greater patient acceptance; however, the effectiveness of glyburide for the treatment of GDM remains controversial.

OBJECTIVE

To compare the perinatal and neonatal outcomes associated with glyburide vs insulin using causal inference methods in a clinical setting with information on glycemic control.

DESIGN, SETTING, AND PARTICIPANTS

The population-based cohort study included patients with GDM who required medication treatment from 2007 to 2017 in Kaiser Permanente Northern California. Machine learning and rigorous casual inference methods with time-varying exposures were used to evaluate associations of exposure to glyburide vs insulin with perinatal outcomes. Data analysis was conducted from March 2018 to July 2017.

EXPOSURES

Time-varying exposure to glyburide vs insulin during pregnancy.

MAIN OUTCOMES AND MEASURES

Outcomes evaluated separately included neonatal hypoglycemia, jaundice, shoulder dystocia, respiratory distress syndrome (RDS), neonatal intensive care unit (NICU) admission, size-for-gestational age, and cesarean delivery. Inverse probability weighting (IPW) estimation was used to separately compare perinatal outcomes between those initiating glyburide and insulin. This approach was combined with Super Learning for propensity score estimation to account for both baseline and time-dependent confounding in both per-protocol (primary) and intention-to-treat (secondary) analyses to evaluate sustained exposure to the same therapy.

RESULTS

From 2007 to 2017, 11 321 patients with GDM (mean [SD] age, 32.9 [4.9] years) initiated glyburide or insulin during pregnancy. In multivariate models, the risk of neonatal respiratory distress was 2.03 (95% CI, 0.13-3.92) per 100 births lower and the risk of NICU admission was 3.32 (95% CI, 0.20-6.45) per 100 births lower after continuous exposure to glyburide compared with insulin. There were no statistically significant differences in glyburide vs insulin initiation in risk for neonatal hypoglycemia (0.85 [95% CI, -1.17 to 2.86] per 100 births), jaundice (0.02 [95% CI, -1.46 to 1.51] per 100 births), shoulder dystocia (-1.05 [95% CI, -2.71 to 0.62] per 100 births), or large-for-gestational age categories (-2.75 [95% CI, -6.31 to 0.80] per 100 births).

CONCLUSIONS AND RELEVANCE

Using data from a clinical setting and contemporary causal inference methods, our findings do not provide evidence of a difference in the outcomes examined between patients with GDM initiating glyburide compared with those initiating insulin.

The intestine and the microbiota in maternal glucose homeostasis during pregnancy

It is now well established that, beyond its role in nutrient processing and absorption, the intestine and its accompanying gut microbiome constitute a major site of immunological and endocrine regulation that mediates whole-body metabolism. Despite the growing field of host-microbe research, few studies explore what mechanisms govern this relationship in the context of pregnancy. During pregnancy, significant maternal metabolic adaptations are made to accommodate the additional energy demands of the developing fetus and to prevent adverse pregnancy outcomes. Recent data suggest that the maternal gut microbiota may play a role in these adaptations, but changes to maternal gut physiology and the underlying intestinal mechanisms remain unclear. In this review, we discuss selective aspects of intestinal physiology including the role of the incretin hormone, glucagon-like peptide 1 (GLP-1), and the role of the maternal gut microbiome in the maternal metabolic adaptations to pregnancy. Specifically, we discuss how bacterial components and metabolites could mediate the effects of the microbiota on host physiology, including nutrient absorption and GLP-1 secretion and action, and whether these mechanisms may change maternal insulin sensitivity and secretion during pregnancy. Finally, we discuss how these pathways could be altered in disease states during pregnancy including maternal obesity and diabetes.

Controversies in Gestational Diabetes

Gestational diabetes mellitus (GDM) complicates approximately 7% of pregnancies in the USA. Despite recognition of the benefits of diagnosing and treating GDM, there are several areas of controversy that remain unresolved. There is debate as to whether to screen for GDM with the one-step versus the two-step approach. While the former identifies more pregnancies with potential adverse outcomes, data are lacking as to whether treatment of these pregnancies will improve outcomes, while increasing costs by diagnosing more women. Though it is well established that the diagnosis of even mild GDM, and treatment with lifestyle recommendations and insulin, improves pregnancy outcomes, it is controversial as to which type and regimen of insulin is optimal, and whether oral agents can be used safely and effectively to control glucose levels. Finally, it is recommended that women with GDM get tested for type 2 diabetes within several months of delivery; however, many women do not undergo this testing and alternative approaches are needed. These controversies are discussed with data from both sides of the debate to enable clinicians to make patient-centered decisions until more definitive data are available.

Pravastatin, proton-pump inhibitors, metformin, micronutrients, and biologics: new horizons for the prevention or treatment of preeclampsia

There has been increasing research momentum to identify new therapeutic agents for the prevention or treatment of preeclampsia, drugs that can affect the underlying disease pathophysiology. Molecular targets of candidate treatments include oxidative stress, antiangiogenic factors, and the angiotensin, nitric oxide, and proinflammatory pathways. The proposed treatments undergoing preclinical and clinical trial evaluation are thought to act on placental or endothelial disease or both. Most have adopted the pragmatic strategy of repurposing drugs. Of all the therapeutic agents proposed, pravastatin has received the most interest. There are preclinical studies showing that it has pleiotropic actions that favorably impact on multiple molecular targets and can resolve a preeclampsia phenotype in many animal models. An early phase clinical trial suggests that it may have therapeutic activity. Several large prevention trials are planned or ongoing and, when completed, could definitively address whether pravastatin can prevent preeclampsia. Proton-pump inhibitors, metformin, and sulfasalazine are other drugs with preclinical evidence of multiple molecular actions that could resolve the pathophysiology of preeclampsia. These agents are also currently being evaluated in clinical trials. There have been many recent preclinical studies identifying the potential of numerous natural compounds to treat preeclampsia, such as plant extracts and micronutrients that have potent anti-inflammatory or antioxidant activity. Recent preclinical studies have also proposed novel molecular-targeted strategies, such as monoclonal antibodies targeting tumor necrosis factor alpha, placental growth factor, and short interfering RNA technology, to silence the gene expression of soluble fms-like tyrosine kinase-1 or angiotensinogen. Other treatment approaches that have transitioned to human trials (ranging from single-arm to phase III trials that have been completed or are ongoing) include folic acid, nitric oxide donors (such as L-arginine), recombinant antithrombin III, digoxin immune antigen-binding fragment, and melatonin. There have been case series showing the removal of circulating soluble fms-like tyrosine kinase-1 may help stabilize the disease and prolong pregnancy. Interestingly, there are case reports suggesting that monoclonal antibody eculizumab (complement inhibitor) may have therapeutic potential. If new agents are discovered that are proven to be effective in preventing or treating preeclampsia, the potential to improve global maternal and perinatal health will be significant.

Changing patterns in medication prescription for gestational diabetes during a time of guideline change in the USA: a cross-sectional study

OBJECTIVE

To define patterns of prescription and factors associated with choice of pharmacotherapy for gestational diabetes mellitus (GDM), namely metformin, glyburide and insulin, during a period of evolving professional guidelines.

DESING

Cross-sectional study.

SETTING

US commercial insurance beneficiaries from Market-Scan (late 2015 to 2018).

STUDY DESIGN

We included women with GDM, singleton gestations, 15-51 years of age on pharmacotherapy. The exposure was pharmacy claims for metformin, glyburide and insulin.

MAIN OUTCOMES

Pharmacotherapy for GDM with either oral agent, metformin or glyburide, compared with insulin as the reference, and secondarily, consequent treatment modification (addition and/or change) to metformin, glyburide or insulin.

RESULTS

Among 37 762 women with GDM, we analysed data from 10 407 (28%) with pharmacotherapy, 21% with metformin (n = 2147), 48% with glyburide (n = 4984) and 31% with insulin (n = 3276). From late 2015 to 2018, metformin use increased from 17 to 29%, as did insulin use from 26 to 44%, whereas glyburide use decreased from 58 to 27%. By 2018, insulin was the most common pharmacotherapy for GDM; metformin was more likely to be prescribed by 9% compared with late 2015/16, but glyburide was less likely by 45%. Treatment modification occurred in 20% of women prescribed metformin compared with 2% with insulin and 8% with glyburide.

CONCLUSIONS

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for GDM among a privately insured US population during a time of evolving professional guidelines. Further evaluation of the relative effectiveness and safety of metformin compared with insulin is needed.

TWEETABLE ABSTRACT

Insulin followed by metformin has replaced glyburide as the most common pharmacotherapy for gestational diabetes mellitus in the USA.

Maternal and early life exposures and their potential to influence development of the microbiome

At the dawn of the twentieth century, the medical care of mothers and children was largely relegated to family members and informally trained birth attendants. As the industrial era progressed, early and key public health observations among women and children linked the persistence of adverse health outcomes to poverty and poor nutrition. In the time hence, numerous studies connecting genetics ("nature") to public health and epidemiologic data on the role of the environment ("nurture") have yielded insights into the importance of early life exposures in relation to the occurrence of common diseases, such as diabetes, allergic and atopic disease, cardiovascular disease, and obesity. As a result of these parallel efforts in science, medicine, and public health, the developing brain, immune system, and metabolic physiology are now recognized as being particularly vulnerable to poor nutrition and stressful environments from the start of pregnancy to 3 years of age. In particular, compelling evidence arising from a diverse array of studies across mammalian lineages suggest that modifications to our metagenome and/or microbiome occur following certain environmental exposures during pregnancy and lactation, which in turn render risk of childhood and adult diseases. In this review, we will consider the evidence suggesting that development of the offspring microbiome may be vulnerable to maternal exposures, including an analysis of the data regarding the presence or absence of a low-biomass intrauterine microbiome.

American Diabetes Association Professional Practice Committee. 15. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Use of metformin to prolong gestation in preterm pre-eclampsia: randomised, double blind, placebo controlled trial

OBJECTIVE

To evaluate whether extended release metformin could be used to prolong gestation in women being expectantly managed for preterm pre-eclampsia.

DESIGN

Randomised, double blind, placebo controlled trial.

SETTING

Referral hospital in Cape Town, South Africa.

PARTICIPANTS

180 women with preterm pre-eclampsia between 26+0 to 31+6 weeks' gestation undergoing expectant management: 90 were randomised to extended release metformin and 90 to placebo.

INTERVENTION

3 g of oral extended release metformin or placebo daily, in divided doses, until delivery.

MAIN OUTCOME MEASURE

The primary outcome was prolongation of gestation.

RESULTS

Of 180 participants, one woman delivered before taking any trial drug. The median time from randomisation to delivery was 17.7 days (interquartile range 5.4-29.4 days; n=89) in the metformin arm and 10.1 (3.7-24.1; n=90) days in the placebo arm, a median difference of 7.6 days (geometric mean ratio 1.39, 95% confidence interval 0.99 to 1.95; P=0.057). Among those who continued to take the trial drug at any dose, the median prolongation of gestation in the metformin arm was 17.5 (interquartile range 5.4-28.7; n=76) days compared with 7.9 (3.0-22.2; n=74) days in the placebo arm, a median difference of 9.6 days (geometric mean ratio 1.67, 95% confidence interval 1.16 to 2.42). Among those who took the full dosage, the median prolongation of gestation in the metformin arm was 16.3 (interquartile range 4.8-28.8; n=40) days compared with 4.8 (2.5-15.4; n=61) days in the placebo arm, a median difference of 11.5 days (geometric mean ratio 1.85, 95% confidence interval 1.14 to 2.88). Composite maternal, fetal, and neonatal outcomes and circulating concentrations of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin did not differ. In the metformin arm, birth weight increased non-significantly and length of stay decreased in the neonatal nursery. No serious adverse events related to trial drugs were observed, although diarrhoea was more common in the metformin arm.

CONCLUSIONS

This trial suggests that extended release metformin can prolong gestation in women with preterm pre-eclampsia, although further trials are needed. It provides proof of concept that treatment of preterm pre-eclampsia is possible.

TRIAL REGISTRATION

Pan African Clinical Trial Registry PACTR201608001752102 https://pactr.samrc.ac.za/.

Maternal Metformin Intervention during Obese Glucose-Intolerant Pregnancy Affects Adiposity in Young Adult Mouse Offspring in a Sex-Specific Manner

Background: Metformin is commonly used to treat gestational diabetes mellitus. This study investigated the effect of maternal metformin intervention during obese glucose-intolerant pregnancy on the gonadal white adipose tissue (WAT) of 8-week-old male and female mouse offspring. Methods: C57BL/6J female mice were provided with a control (Con) or obesogenic diet (Ob) to induce pre-conception obesity. Half the obese dams were treated orally with 300 mg/kg/d of metformin (Ob-Met) during pregnancy. Gonadal WAT depots from 8-week-old offspring were investigated for adipocyte size, macrophage infiltration and mRNA expression of pro-inflammatory genes using RT-PCR. Results: Gestational metformin attenuated the adiposity in obese dams and increased the gestation length without correcting the offspring in utero growth restriction and catch-up growth caused by maternal obesity. Despite similar body weight, the Ob and Ob-Met offspring of both sexes showed adipocyte hypertrophy in young adulthood. Male Ob-Met offspring had increased WAT depot weight (p < 0.05), exaggerated adipocyte hyperplasia (p < 0.05 vs. Con and Ob offspring), increased macrophage infiltration measured via histology (p < 0.05) and the mRNA expression of F4/80 (p < 0.05). These changes were not observed in female Ob-Met offspring. Conclusions: Maternal metformin intervention during obese pregnancy causes excessive adiposity, adipocyte hyperplasia and WAT inflammation in male offspring, highlighting sex-specific effects of prenatal metformin exposure on offspring WAT.

Interaction between Metformin, Folate and Vitamin B12 and the Potential Impact on Fetal Growth and Long-Term Metabolic Health in Diabetic Pregnancies

Metformin is the first-line treatment for many people with type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) to maintain glycaemic control. Recent evidence suggests metformin can cross the placenta during pregnancy, thereby exposing the fetus to high concentrations of metformin and potentially restricting placental and fetal growth. Offspring exposed to metformin during gestation are at increased risk of being born small for gestational age (SGA) and show signs of ‘catch up’ growth and obesity during childhood which increases their risk of future cardiometabolic diseases. The mechanisms by which metformin impacts on the fetal growth and long-term health of the offspring remain to be established. Metformin is associated with maternal vitamin B₁₂ deficiency and antifolate like activity. Vitamin B₁₂ and folate balance is vital for one carbon metabolism, which is essential for DNA methylation and purine/pyrimidine synthesis of nucleic acids. Folate:vitamin B₁₂ imbalance induced by metformin may lead to genomic instability and aberrant gene expression, thus promoting fetal programming. Mitochondrial aerobic respiration may also be affected, thereby inhibiting placental and fetal growth, and suppressing mammalian target of rapamycin (mTOR) activity for cellular nutrient transport. Vitamin supplementation, before or during metformin treatment in pregnancy, could be a promising strategy to improve maternal vitamin B₁₂ and folate levels and reduce the incidence of SGA births and childhood obesity. Heterogeneous diagnostic and screening criteria for GDM and the transient nature of nutrient biomarkers have led to inconsistencies in clinical study designs to investigate the effects of metformin on folate:vitamin B₁₂ balance and child development. As rates of diabetes in pregnancy continue to escalate, more women are likely to be prescribed metformin; thus, it is of paramount importance to improve our understanding of metformin’s transgenerational effects to develop prophylactic strategies for the prevention of adverse fetal outcomes.

Impact of metformin treatment during pregnancy on maternal outcomes: a systematic review/meta-analysis

We systematically assessed the impact of metformin treatment on maternal pregnancy outcomes. PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov and Cochrane databases were systematically searched (inception-1st February 2021). Randomised controlled trials reporting pregnancy outcomes in women randomised to metformin versus any other treatment for any indication were included. Outcomes included gestational weight gain (GWG), pre-eclampsia, gestational hypertension, preterm birth, gestational age at delivery, caesarean section, gestational diabetes, glycaemic control, and gastrointestinal side-effects. Two independent reviewers conducted screening, with a third available to evaluate disagreements. Risk-of-bias and GRADE assessments were conducted using Cochrane Risk-of-Bias and GRADE-pro software. Thirty-five studies (n = 8033 pregnancies) met eligibility criteria. GWG was lower in pregnancies randomised to metformin versus other treatments (1.57 kg ± 0.60 kg; I₂ = 86%, p < 0.0001), as was likelihood of pre-eclampsia (OR 0.69, 95% CI 0.50-0.95; I₂ = 55%, p = 0.02). The risk of gastrointestinal side-effects was greater in metformin-exposed versus other treatment groups (OR 2.43, 95% CI 1.53-3.84; I₂ = 76%, p = 0.0002). The risk of other maternal outcomes assessed was not significantly different between metformin-exposed versus other treatment groups. Metformin for any indication during pregnancy is associated with lower GWG and a modest reduced risk of pre-eclampsia, but increased gastrointestinal side-effects compared to other treatments.

Management of Women with Polycystic Ovary Syndrome During Pregnancy

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

14. Management of Diabetes in Pregnancy: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Fetal macrosomia in a Hispanic/Latinx predominant cohort and altered expressions of genes related to placental lipid transport and metabolism

Fetal overgrowth, termed fetal macrosomia when birth weight is greater than 4000 grams, is the major concern in the treatment of gestational diabetes mellitus (GDM). However, to date, the underlying mechanisms of fetal macrosomia have not been understood completely. Placental lipid metabolism is emerging as a critical player in fetal growth. In this study, we hypothesized that fatty acid transport and metabolism in the placental tissue was impaired in GDM women, dependent on fetal sex. To test this hypothesis, we analyzed the incidence of GDM, fetal macrosomia, and obesity in a large cohort consisting of 17995 pregnant subjects and majority of subjects being Hispanic/Latinx, and investigated expression of genes related to lipid transport and metabolism in placenta from obese women with or without GDM, and with or without fetal macrosomia. The main findings include: 1) There is a higher incidence of GDM and obesity in Hispanic subjects compared to non-Hispanic subjects, but not fetal macrosomia; 2) Expressions of most of genes related to placental lipid transport and metabolism are not altered by the presence of GDM, fetal macrosomia, or fetal sex; 3) Expression of FABP4 is increased in obese women with GDM and fetal macrosomia, and this occurred in male placentas; 4) Expression of LPL is decreased in obese women with GDM despite fetal macrosomia, and this occurred in male placentas; 5) Expression of ANGPTL3 is decreased in obese women with GDM and fetal macrosomia, but is not altered when fetal sex is included in the analysis. This study indicates that there is race disparity in GDM with higher incidence of GDM in obese Hispanic women, although fetal macrosomia disparity is not present. Moreover, altered placental lipid transport may contribute to fetal overgrowth in obese women with GDM.

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

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

Is there a definite relationship between placental mTOR signaling and fetal growth?

Fetal growth restriction and overgrowth are common obstetrical complications that result in adverse perinatal outcomes and long-term health risks later in life, including neurodevelopmental dysfunction and adult metabolic syndrome. The placenta plays a critical role in the nutrition transfer from mother to fetus and even exerts adaptive mechanism when the fetus is under poor developmental conditions. The mammalian/mechanistic target of rapamycin (mTOR) signaling serves as a critical hub of cell growth, survival, and metabolism in response to nutrients, growth factors, energy, and stress signals. Placental mTOR signaling regulates placental function, including oxygen and nutrient transport. Therefore, placental mTOR signaling is hypothesized to have a positive relationship with fetal growth. In this review, we summarize that most studies support the current evidence that there is connection between placental mTOR signaling and abnormal fetal growth; however, but more studies should be performed following a vigorous and unanimous method for assessment to determine placental mTOR activity.

The effect of dipeptidyl peptidase-4 inhibitor and glucagon-like peptide-1 receptor agonist in gestational diabetes mellitus: a systematic review

Gestational diabetes mellitus (GDM) is the most common complication in pregnancy and affects 13% pregnant women around the world. GDM has both short-term and long-term negative effect on mother and offspring. Dipeptidyl peptidase-4 (DPP-4) inhibitor and glucagon-like peptide-1 receptor agonist (GLP-1 Ra) have shown many extra-benefits in diabetes patients, and may be a promising choice to GDM. Here, we conducted a systematic review of randomized controlled trials to investigate the effect of DPP-4 inhibitor and GLP-1 Ra in GDM. This project was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) statement. We searched PubMed, EMBASE and Cochrane library up to November 8 2019 for eligible trials. A total of 982 records were identified and 4 trials (516 participants) met the criteria in the end. The results suggested that DPP-4 inhibitor and GLP-1 Ra can reduce the rate of developing postpartum diabetes, help to normalization of blood glucose and improve insulin resistance and β-cell function. Although the treatments showed beneficial effects in GDM patients, but the present data could not prove it use in GDM. Further clinical trials will be needed.

Metformin and Pregnancy Outcomes: Evidence Gaps and Unanswered Questions

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of Gestational Diabetes Mellitus

Once a woman is diagnosed with gestational diabetes mellitus (GDM), two strategies are considered for management; life-style modifications and pharmacological therapy. The management of GDM aims to maintain a normoglycemic state and to prevent excessive weight gain in order to reduce maternal and fetal complications. Lifestyle modifications include nutritional therapy and exercise. Calorie restriction with a low glycemic index diet is recommended to avoid postprandial hyperglycemia and to reduce insulin resistance. Blood glucose levels, HbA1c levels, and ketonuria are monitored to analyze the efficacy of conservative management. Pharmacological treatment is initiated if conservative strategies fail to provide expected glucose levels during follow-ups.Insulin has been the first choice for the treatment of diabetes during pregnancy. Recently, metformin has been used more commonly in diabetic pregnant women in cases when insulin cannot be prescribed, after its safety has been proven. However, a high percentage of women, which may be up to 46% may require additional insulin to maintain expected blood glucose levels. The evidence on the long-term safety of other oral anti-diabetics has been lacking yet.Women with diet-controlled GDM can wait for spontaneous labor expectantly in case there are no obstetric indications for birth. However, in women with GDM under insulin therapy or with poor glycemic control, elective induction at term is recommended by authorities.The women who have GDM during pregnancy should be counseled about their increased risks of impaired glucose tolerance, type 2 diabetes mellitus, hypertensive disorders, cardiovascular diseases, and metabolic syndrome.