Association between pregnancy-related complications and development of type 2 diabetes and hypertension in women: an umbrella review.

BACKGROUND: Despite many systematic reviews and meta-analyses examining the associations of pregnancy complications with risk of type 2 diabetes mellitus (T2DM) and hypertension, previous umbrella reviews have only examined a single pregnancy complication. Here we have synthesised evidence from systematic reviews and meta-analyses on the associations of a wide range of pregnancy-related complications with risk of developing T2DM and hypertension. METHODS: Medline, Embase and Cochrane Database of Systematic Reviews were searched from inception until 26 September 2022 for systematic reviews and meta-analysis examining the association between pregnancy complications and risk of T2DM and hypertension. Screening of articles, data extraction and quality appraisal (AMSTAR2) were conducted independently by two reviewers using Covidence software. Data were extracted for studies that examined the risk of T2DM and hypertension in pregnant women with the pregnancy complication compared to pregnant women without the pregnancy complication. Summary estimates of each review were presented using tables, forest plots and narrative synthesis and reported following Preferred Reporting Items for Overviews of Reviews (PRIOR) guidelines. RESULTS: Ten systematic reviews were included. Two pregnancy complications were identified. Gestational diabetes mellitus (GDM): One review showed GDM was associated with a 10-fold higher risk of T2DM at least 1 year after pregnancy (relative risk (RR) 9.51 (95% confidence interval (CI) 7.14 to 12.67) and although the association differed by ethnicity (white: RR 16.28 (95% CI 15.01 to 17.66), non-white: RR 10.38 (95% CI 4.61 to 23.39), mixed: RR 8.31 (95% CI 5.44 to 12.69)), the between subgroups difference were not statistically significant at 5% significance level. Another review showed GDM was associated with higher mean blood pressure at least 3 months postpartum (mean difference in systolic blood pressure: 2.57 (95% CI 1.74 to 3.40) mmHg and mean difference in diastolic blood pressure: 1.89 (95% CI 1.32 to 2.46) mmHg). Hypertensive disorders of pregnancy (HDP): Three reviews showed women with a history of HDP were 3 to 6 times more likely to develop hypertension at least 6 weeks after pregnancy compared to women without HDP (meta-analysis with largest number of studies: odds ratio (OR) 4.33 (3.51 to 5.33)) and one review reported a higher rate of T2DM after HDP (hazard ratio (HR) 2.24 (1.95 to 2.58)) at least a year after pregnancy. One of the three reviews and five other reviews reported women with a history of preeclampsia were 3 to 7 times more likely to develop hypertension at least 6 weeks postpartum (meta-analysis with the largest number of studies: OR 3.90 (3.16 to 4.82) with one of these reviews reporting the association was greatest in women from Asia (Asia: OR 7.54 (95% CI 2.49 to 22.81), Europe: OR 2.19 (95% CI 0.30 to 16.02), North and South America: OR 3.32 (95% CI 1.26 to 8.74)). CONCLUSIONS: GDM and HDP are associated with a greater risk of developing T2DM and hypertension. Common confounders adjusted for across the included studies in the reviews were maternal age, body mass index (BMI), socioeconomic status, smoking status, pre-pregnancy and current BMI, parity, family history of T2DM or cardiovascular disease, ethnicity, and time of delivery. Further research is needed to evaluate the value of embedding these pregnancy complications as part of assessment for future risk of T2DM and chronic hypertension.

The effectiveness of pharmacological and lifestyle interventions to reduce the risk of diabetes and hyperglycaemia following gestational diabetes: A systematic review and meta-analysis.

AIMS: To synthesize the available evidence to better understand the effectiveness of interventions to prevent or delay hyperglycaemia and Type 2 diabetes mellitus (T2DM) postnatally in women with current or previous gestational diabetes mellitus (GDM). METHODS: We searched five databases up to December 2020 for primary peer-reviewed articles reporting postpartum glycaemic outcomes in women with (previous) GDM following pharmacological or lifestyle intervention. Outcomes were relative risk of T2DM or continuous measures of glycaemia, change or at follow-up. A minimum of two studies evaluating the same intervention-outcome combination were needed to conduct meta-analyses, otherwise studies were described narratively. Meta-regression was used to evaluate whether associations varied by additional variables. We assessed risk of bias using the Critical Appraisal Skills Programme checklist. PROSPERO record CRD42018102380. RESULTS: We included 31 studies in the review with a total sample size of 8624 participants, and 26 studies in meta-analyses. Two-thirds of studies followed up participants at 1 year or less. Pharmacological interventions were associated with reduced risk of T2DM (0.80 [95% CI 0.64-1.00], n = 6 studies), as were lifestyle interventions albeit with a smaller effect size (0.88 [95% CI 0.76-1.01], n = 12 studies). Dietary and physical activity interventions were associated with a small reduction in fasting plasma glucose, particularly in longer interventions, but inconsistent effects were seen for other continuous outcomes. CONCLUSIONS: Although possibly due to chance, interventions to reduce hyperglycaemia after GDM may be effective. Future research should improve understanding of how interventions affect glucose control and how to optimise interventions for this population.

Mapping Lifestyle Interventions for Gestational Diabetes Prevention: A Scoping Review.

PURPOSE OF REVIEW: The purpose of this study was to conduct a scoping review to map intervention, sample, and physiologic measurement characteristics of lifestyle interventions for gestational diabetes mellitus (GDM) prevention. RECENT FINDINGS: A total of 19 studies met selection criteria from 405 articles screened (PubMed, Web of Science). No studies were US-based (47% multi-site), and all were delivered in clinical settings. The most targeted nutrition components were low carbohydrate intake (sugar rich foods/added sugars, low glycemic index), low fat intake (mainly low-fat meat, dairy, and saturated fat), and increased fruits and vegetables. Many studies promoted 150 min/week moderate-intensity physical activity. Only two studies provided supervised physical activity sessions. Dietitians and nurses were the most common implementers. Samples were characterized as adults with obesity (mean age 31 yr, BMI 31 kg/m2). Asian populations were predominantly studied. Four studies used theoretical frameworks (75% of which used Social Cognitive Theory). GDM diagnostic criteria set forth by the American Diabetes Association were the most widely used. Insulin sensitivity was commonly assessed via fasting indices. There was a lack of multi-disciplinary, multi-level, and theory-based lifestyle interventions for reducing GDM risk. Addressing these gaps and prioritizing high-risk populations in the US with measurement of traditional and novel biomarkers will advance the field.

REduced-Carbohydrate intervention for managing Obesity and Reduction of gestational Diabetes (RECORD): A randomized controlled feasibility trial.

AIM: To test the feasibility and acceptability of a reduced-carbohydrate dietary program, intended to reduce the risk of gestational diabetes. MATERIALS AND METHODS: Fifty-one pregnant women at <20 weeks' gestation, with body mass index ≥30 kg/m2 , and a normal baseline oral glucose tolerance test (OGTT), were randomized 2:1 to an intervention or control group and followed-up until delivery. The dietary intervention aimed at providing 130-150 g carbohydrate/day. Feasibility outcomes assessed at 24-28 weeks' gestation, included adoption of the reduced-carbohydrate diet by the intervention group, and retention of all participants, assessed by completion of a second OGTT. Changes in glycemia, weight gain and dietary intake, and the maternal and neonatal outcomes were also assessed. Participants were interviewed about their experience of the intervention and the study. RESULTS: Forty-nine of 51 participants attended the follow-up OGTT, a retention rate of 96% (95% confidence interval [CI] 86.8%-98.9%). In the intervention group, carbohydrate intake at follow-up was 190.4 (95% CI 162.5-215.6) g/day, a reduction of -24.6 (95% CI -51.5-2.4) g/day from baseline. Potentially favourable effects of the intervention on glucose control, weight gain and blood pressure were observed, but the study was not powered to detect significant differences in these. Participants found the intervention acceptable, and were content with the study processes, but some reported barriers to sustained adherence, mainly pertaining to competing priorities. CONCLUSIONS: Retention was high, suggesting the study processes are feasible, but the carbohydrate reduction in the intervention group was small, and did not meet progression criteria, limiting the likelihood of achieving the desired goal to prevent gestational diabetes. TRIAL REGISTRATION NUMBER: ISRCTN16235884.

Liraglutide treatment for the prevention of glucose tolerance deterioration in women with prior gestational diabetes mellitus: A 52-week randomized controlled clinical trial.

AIM: We investigated the effect of 52-week treatment with liraglutide, a glucagon-like peptide 1 receptor agonist, on glucose tolerance and incretin effect in women with previous gestational diabetes mellitus (pGDM). MATERIALS AND METHODS: Women with overweight/obesity and pGDM were randomized to once daily subcutaneous liraglutide 1.8 mg or placebo for 52 weeks. Participants underwent oral glucose tolerance test (OGTT) and isoglycaemic intravenous glucose infusion at baseline and at 52 weeks, and an additional OGTT after the drug wash-out. RESULTS: In total, 104 women [age: mean ± SD, 38 ± 5 years; fasting plasma glucose (FPG): 5.5 ± 0.4 mmol/L; glycated haemoglobin (HbA1c): 33 ± 4 mmol/mol, bodyweight: 88.2 ± 14.8 kg, body mass index: 31.1 ± 4.3 kg/m2 ] were assigned to liraglutide (n = 49) or placebo (n = 55). Estimated treatment difference (ETD) for area under curve during OGTT was -173 (95% confidence interval -250 to -97) mmol/L × min, p < .0001, but after wash-out the difference disappeared [ETD 58 (-30 to 146) mmol/L × min, p = .536]. Liraglutide reduced FPG [ETD -0.2 (-0.4 to -0.1) mmol/L, p = .018], HbA1c [-2.2 (-3.5 to -0.8) mmol/mol, p = .018] and bodyweight [-3.9 (-6.2 to -1.6) kg, p = .012]. No change in the incretin effect was observed. The number of women with prediabetes was reduced from 64% to 10% with liraglutide vs. 50% with placebo [adjusted odds ratio 0.10 (0.03-0.32), p = .002]. CONCLUSIONS: Treatment with liraglutide for 52 weeks improved glucose tolerance, FPG, HbA1c and bodyweight in women with overweight/obesity and pGDM. Progression to prediabetes while on drug was markedly reduced, but after a 1-week drug wash-out, the effect was lost.

Intrapartum maternal glycaemic control for the prevention of neonatal hypoglycaemia: a systematic review and meta-analysis.

BACKGROUND: Neonatal hypoglycaemia is the most common metabolic disorder in infants, and may be influenced by maternal glycaemic control. This systematic review evaluated the effect of intrapartum maternal glycaemic control on neonatal hypoglycaemia. METHODS: We included randomised controlled trials (RCTs), quasi-RCTs, non-randomised studies of interventions, and cohort or case-control studies that examined interventions affecting intrapartum maternal glycaemic control compared to no or less stringent control. We searched four databases and three trial registries to November 2023. Quality assessments used Cochrane Risk of Bias 1 or the Effective Public Health Practice Project Quality Assessment Tool. Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Meta-analysis was performed using random-effects models analysed separately for women with or without diabetes. The review was registered prospectively on PROSPERO (CRD42022364876). RESULTS: We included 46 studies of women with diabetes and five studies of women without diabetes: one RCT, 32 cohort and 18 case-control studies (11,273 participants). For women with diabetes, the RCT showed little to no difference in the incidence of neonatal hypoglycaemia between tight versus less tight intrapartum glycaemic control groups (76 infants, RR 1.00 (0.45, 2.24), p = 1.00, low certainty evidence). However, 11 cohort studies showed tight intrapartum glycaemic control may reduce neonatal hypoglycaemia (6,152 infants, OR 0.44 (0.31, 0.63), p < 0.00001, I2 = 58%, very low certainty evidence). For women without diabetes, there was insufficient evidence to determine the effect of tight intrapartum glycaemic control on neonatal hypoglycaemia. CONCLUSIONS: Very uncertain evidence suggests that tight intrapartum glycaemic control may reduce neonatal hypoglycaemia in infants of women with diabetes. High-quality RCTs are required.

Getting a "SMART START" to gestational diabetes mellitus education: a mixed-methods pilot evaluation of a knowledge translation tool in primary care.

BACKGROUND: South Asian people living in Canada face higher rates of gestational diabetes mellitus (GDM) compared to national trends. The objective of this study was to design and pilot test a knowledge translation (KT) tool to support GDM prevention counselling in primary care. METHODS: This study is a mixed-methods pilot evaluation of the "SMART START" KT tool involving 2 family physicians in separate practices and 20 pregnant South Asians in Ontario, Canada. We conducted the quantitative and qualitative components in parallel, developing a joint display to illustrate the converging and diverging elements. RESULTS: Between January and July 2020, 20 South Asian pregnant people were enrolled in this study. A high level of acceptability was received from patients and practitioners for timing, content, format, language, and interest in the interventions delivered. Quantitative findings revealed gaps in patient knowledge and behaviour in the following areas: GDM risk factors, the impact of GDM on the unborn baby, weight gain recommendations, diet, physical activity practices, and tracking of weight gain. From the qualitative component, we found that physicians valued and were keen to engage in GDM prevention counselling. Patients also expressed personal perceptions of healthy active living during pregnancy, experiences, and preferences with gathering and searching for information, and key preventative behaviours. CONCLUSIONS: Building on this knowledge can contribute to the design and implementation of other research opportunities or test new hypotheses as they relate to GDM prevention among South Asian communities.

Explaining the experience of breastfeeding in women with gestational diabetes and designing and implementing an educational program based on planned behavior theory: a combined exploratory study protocol.

BACKGROUND: Gestational diabetes is a type of carbohydrate intolerance that is diagnosed for the first time during pregnancy. Researches have shown that gestational diabetes is associated with many negative prenatal and birth outcomes. Because of the complications such as infant death, several diabetics' mothers plan to stop breastfeeding. Research findings indicate a decrease in breastfeeding in mothers with gestational diabetes/ or contradictory tissues regarding the factors affecting the breastfeeding behavior of mothers with gestational diabetes and a special program to promote breastfeeding for these mothers based on the social and cultural conditions of Iranian society. The present study aims to design an interventional program with a mixed qualitative study based on the theory of planned behavior (PBT) to prevent the decrease of breastfeeding in diabetic mothers. METHODS/DESIGN: A mixed methods exploratory design will be used to conduct this study in 3 phases. The first phase (qualitative): The purpose of the first phase is to understand the experience of breastfeeding mothers who had gestational diabetes, which will be done using the directed content analysis method. The purposive sampling will be used on pregnant mothers with gestational diabetes 30-34 weeks and mothers with infants (up to 6 months) with a history of gestational diabetes. The second phase include designing and implementing an educational program based on the PBT: Education will be conducted based on the needs assessment of the qualitative phase, the opinions of the focus group, and the literature review, then the breastfeeding behavior will be measured using the survey tool of "breastfeeding drop". The third phase: Interventional quantitative phase: The sample size will be carried out by a pilot study, then a designed program as an educational intervention for teaching breastfeeding behavior based on the PBT for 30-34 weeks pregnant mothers with gestational diabetes will be implemented during 3-4 sessions and breastfeeding behavior will be evaluated after delivery. DISCUSSION: This is the first mixed-method study in Iran that led to implement an interventional program based on the theory of planned behavior. Because of the complications such as infant death, several diabetics' mothers plan to stop breastfeeding. We hope that the result of this research will be a step in solving breastfeeding problems in mothers with gestational diabetes.

Gestational diabetes is a type of carbohydrate intolerance diagnosed for the first time during pregnancy. The rate of gestational diabetes has increased along with the increase in the prevalence of diabetes risk factors. It is associated with multiple prenatal and birth outcomes. Despite the incomparable benefits of breastfeeding providing health to gestational diabetes mothers, the rate of breastfeeding is low. This is the first study in Iran using a mixed method approach in 3 phases to implement an educational interventional program with a qualitative study directed by theory of planned behavior (TPB) to prevent the decrease of breastfeeding in mothers with gestational diabetes. The purpose of first phase of study (qualitative) is to understand women's experience of gestational diabetes, which will be done using the directed content analysis method. The purposive sampling will be used for pregnant mothers with gestational diabetes at 30­34 weeks and mothers with infants (up to 6 months). The second phase is designing and implementing an educational program based on the PBT: Educational aims and content will be prepared based on the need achieved in the qualitative phase, the opinions of the focus group with experts? Mothers? Whom? And the literature review, then the breastfeeding behavior will be measured using the survey tool "breastfeeding drop". The third phase includes: Interventional quantitative phase an educational program will be implemented for training breastfeeding behavior based on the theory of PBT for 30­34 weeks pregnant mothers with gestational diabetes. This program will be administered as an educational intervention during 3­4 sessions and breastfeeding behavior will be evaluated after delivery.

Inositol supplementation for the prevention and treatment of gestational diabetes mellitus: a meta-analysis of randomized controlled trials.

BACKGROUND: Inositol is a potential new therapeutic agent for gestational diabetes mellitus (GDM), but its effectiveness is still controversial. The aim of the report was to evaluate the effectiveness of inositol to preventing or reducing the severity of GDM. METHODS: We searched PubMed, EmBase, Web of science, Cochrane library databases, Clinicaltrials.gov, and International Clinical Trials Registry Platform for randomized controlled trials (RCTs) assessing the effectiveness of inositol supplementation to prevent and treat GDM. This meta-analysis was performed using the random-effects model. RESULTS: A total of 7 RCTs (1319 pregnant women at high risk of GDM) were included in the meta-analysis. The meta-analysis found that inositol supplementation resulted in a significantly lower incidence of GDM in the inositol versus the control group (odds ratio [OR] 0.40; 95% confidence interval [CI] 0.24-0.67; P = 0.0005). The inositol group had improved fasting glucose oral glucose tolerance test (FG OGTT; mean difference [MD] = - 3.20; 95% CI - 4.45 to - 1.95; P < 0.00001), 1-h OGTT (MD = - 7.24; 95% CI - 12.23 to - 2.25; P = 0.004), and 2-h OGTT (MD = - 7.15; 95% CI - 12.86 to - 1.44; P = 0.01) results. Inositol also reduced the risk of pregnancy-induced hypertension (OR 0.37; 95% CI 0.18-0.75; P = 0.006) and preterm birth (OR 0.35; 95% CI 0.18-0.69; P = 0.003). A meta-analysis of 4 RCTs including 320 GDM patients showed that the patients' insulin resistance (P < 0.05) and neonatal hypoglycemia risk (OR 0.10, 95% CI 0.01-0.88; P = 0.04) were lower in the inositol than in the control group. CONCLUSIONS: Inositol supplementation during pregnancy has the potential to prevent GDM, improve glycemic control, and reduce preterm birth rates.

The protective association of dairy intake and the adverse impact of iron on gestational diabetes risk.

Background: Gestational diabetes (GDM) is a pregnancy-related glucose intolerance with significant implications for maternal and fetal health. Calcium is essential for insulin secretion and metabolism, while iron intake may also impact GDM. This case-control study was conducted to investigate the relationship between calcium and iron intake with the risk of GDM. Methods: GDM was defined as Fasting Blood Sugar>92mg/dL or 75g Oral-Glucose-Tolerance-Test 120-minutes>153mg/dL. A 168-Item food-frequency-questionnaire was used to collect dietary calcium and iron intake from 24-40 weeks of gestation. The impact of total iron, red, processed/unprocessed meat consumption, calcium, and dairy intake on GDM were investigated. Results: A total of 229 GDM and 205 non-GDM women (18-45 years) participated. GDM group had higher pre-pregnancy weight, weight gain, and pre-pregnancy BMI. Across all models, GDM risk significantly increased in the third and fourth quartiles of iron intake. The fourth quartile had an Odds Ratio (OR) of 2.68 (CI 95%, 4.89-1.56; P<0.001) compared to the reference. Heme-iron consumption in the fourth quartiles increased GDM risk. In the second calcium intake model, ORs for the second, third, and fourth quartiles were 0.51 (CI 95%, 0.91-0.25), 0.43 (CI 95%, 0.77-0.24), and 0.35 (CI 95%, 0.63-0.19), respectively (P<0.001 all), reducing GDM risk by 50-65% compared to the first quartile. Dairy consumption in all quartiles of the first and second models was associated with lower GDM risk. Conclusions: Consumption of heme-iron through red and processed meat associated with an increased chance of developing GDM. Dairy intake reduces the chances of developing GDM in pregnant women.

Long-term cost-effectiveness of implementing a lifestyle intervention during pregnancy to reduce the incidence of gestational diabetes and type 2 diabetes.

AIMS/HYPOTHESIS: The aim of this study was to determine the long-term cost-effectiveness and return on investment of implementing a structured lifestyle intervention to reduce excessive gestational weight gain and associated incidence of gestational diabetes mellitus (GDM) and type 2 diabetes mellitus. METHODS: A decision-analytic Markov model was used to compare the health and cost-effectiveness outcomes for (1) a structured lifestyle intervention during pregnancy to prevent GDM and subsequent type 2 diabetes; and (2) current usual antenatal care. Life table modelling was used to capture type 2 diabetes morbidity, mortality and quality-adjusted life years over a lifetime horizon for all women giving birth in Australia. Costs incorporated both healthcare and societal perspectives. The intervention effect was derived from published meta-analyses. Deterministic and probabilistic sensitivity analyses were used to capture the impact of uncertainty in the model. RESULTS: The model projected a 10% reduction in the number of women subsequently diagnosed with type 2 diabetes through implementation of the lifestyle intervention compared with current usual care. The total net incremental cost of intervention was approximately AU$70 million, and the cost savings from the reduction in costs of antenatal care for GDM, birth complications and type 2 diabetes management were approximately AU$85 million. The intervention was dominant (cost-saving) compared with usual care from a healthcare perspective, and returned AU$1.22 (95% CI 0.53, 2.13) per dollar invested. The results were robust to sensitivity analysis, and remained cost-saving or highly cost-effective in each of the scenarios explored. CONCLUSIONS/INTERPRETATION: This study demonstrates significant cost savings from implementation of a structured lifestyle intervention during pregnancy, due to a reduction in adverse health outcomes for women during both the perinatal period and over their lifetime.

Acceptability and adoption of the Face-it health promotion intervention targeting women with prior gestational diabetes and their partners: A qualitative study of the perspectives of healthcare professionals.

AIM: In this study, we investigated healthcare professionals' (HCPs) experiences with delivering home visits and digital coaching in the Face-it health promotion intervention targeting women with recent GDM and their families. Understanding the acceptability and adoption of a health promotion intervention can provide insights into intervention fidelity and future scalability. METHODS: In total, 13 HCPs were interviewed. Data were analysed thematically through an abductive approach using Sekhon et al.'s theoretical framework of acceptability and Greenhalgh et al.'s framework for non-adoption, abandonment, scale-up, spread, and sustainability. RESULTS: Acceptability and adoption of the intervention among HCPs were influenced by (1) skills and technology, (2) values, and (3) organisation. The intervention was experienced as acceptable to HCPs because the dialogue tool, visualising different topics, used in the home visits and digital coaching through the LIVA app were flexible and enabled them to address psychosocial health and personalise goal setting in families. However, delivering asynchronous and non-verbal communication was experienced as straining HCPs' relationship with families, which misaligned with HCPs' values. Establishing a non-judgemental environment was needed to increase intervention acceptability among HCPs towards addressing type 2 diabetes risk after GDM. Increased collaboration between HCPs may have aligned advice and support to families and could have benefitted delivery. CONCLUSIONS: When delivering health promotion to women with prior GDM, flexible intervention components that support psychosocial- and mental health topics may increase acceptability and adoption of the intervention among HCPs. HCPs' skills, values, and organisational factors should be considered prior and during implementation.

Randomized controlled trial of prepregnancy lifestyle intervention to reduce recurrence of gestational diabetes mellitus.

BACKGROUND: Preconception lifestyle intervention holds potential for reducing gestational diabetes mellitus, but clinical trial data are lacking. OBJECTIVE: This study aimed to determine the effects of a prepregnancy weight loss intervention on gestational diabetes mellitus recurrence in women with overweight/obesity and previous gestational diabetes mellitus. STUDY DESIGN: A 2-site, randomized controlled trial comparing a prepregnancy lifestyle intervention with educational control was conducted between December 2017 and February 2022. A total of 199 English- and Spanish-speaking adults with overweight/obesity and previous gestational diabetes mellitus were randomized to a 16-week prepregnancy lifestyle intervention with ongoing treatment until conception or educational control. The primary outcome was gestational diabetes mellitus recurrence. Analyses excluded 6 participants who conceived but did not have gestational diabetes mellitus ascertained by standard methods. RESULTS: In the 63 (33%) women who conceived and had gestational diabetes mellitus ascertained (Ns=38/102 [37%] intervention vs 25/91 [28.0%] control; P=.17), those in the intervention group had significantly greater weight loss at 16 weeks compared with controls (4.8 [3.4-6.0] vs 0.7 [-0.9 to 2.3] kg; P=.001) and a greater proportion lost ≥5% of body weight (50.0% [17/34] vs 13.6% [3/22]; P=.005). There was no significant difference in the incidence of gestational diabetes mellitus recurrence between the intervention (57.9% [ns=23/38]) and the control group (44.0% [ns=11/25]; odds ratio, 1.8 [0.59-5.8]). Independent of group, greater prepregnancy weight loss predicted 21% lower odds of gestational diabetes mellitus recurrence (odds ratio, 0.79 [0.66-0.94]; P=.008). A ≥5% weight loss before conception reduced the odds of gestational diabetes mellitus recurrence by 82% (odds ratio, 0.18 [0.04-0.88]; P=.03). CONCLUSION: Lifestyle intervention produced considerable prepregnancy weight loss but did not affect gestational diabetes mellitus rates. Given that the conception rate was 50% lower than expected, this study was underpowered.

Impact of iron supplementation on gestational diabetes mellitus: A literature review.

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, affecting 14% of pregnancies worldwide, and the prevention of pathological hyperglycaemia during pregnancy is meaningful for global public health. The role of iron supplementation in the progression of GDM has been of significant interest in recent years. Iron is a micronutrient that is vital during pregnancy; however, given the toxic properties of excess iron, it is probable that prophylactic iron supplementation will increase the risk of adverse pregnancy outcomes, including GDM. It is critical to clarify the effect of iron supplementation on the risk of GDM. Therefore, in this review, we comprehensively assess the role of iron in pregnancy. This review aimed to analyse the necessity of iron supplementation and maintenance of iron homeostasis during pregnancy, particularly reviewing the role and function of iron in beta cells and examining the mechanisms of excess iron contributing to the pathogenesis of GDM. Moreover, we aimed to discuss the association of haemoglobin and ferritin with GDM and identify priority areas for research.

Lifestyle intervention for the prevention of type 2 diabetes in women with prior gestational diabetes: A systematic review and meta-analysis.

AIM: To determine whether current evidence supports lifestyle intervention for type 2 diabetes (T2D) prevention in women with previous gestational diabetes (GD). METHODS: We systematically searched MEDLINE/PubMed, Web of Science, EMBASE, The Cochrane Library, International Pharmaceutical Abstracts, Global Health, Sinomed and Clinicaltrials.gov for randomized controlled trials (published from 1 January 1950 to 14 December 2022) comparing lifestyle intervention with standard care in women with previous GD. Our primary outcome was incident T2D, with pooled estimates calculated by a fixed-effects model. RESULTS: Of 1652 studies identified, 13 were eligible and were included in our analysis (N = 3745 women). Compared with standard care, lifestyle intervention yielded a reduction of 24% in the incidence of T2D (relative risk 0.76 [95% CI 0.63-0.93]). Meta-regression analyses revealed no impact of the duration of lifestyle intervention (P = .81) or baseline body mass index (P = .90) on the observed reduction in incident T2D. Importantly, this published literature shows evidence of publication bias on funnel plot and Egger test (P = .048). CONCLUSIONS: Current published evidence suggests that lifestyle intervention can reduce the risk of T2D in women with prior GD. However, this finding should be interpreted with caution in the presence of documented publication bias.

Exercise during pregnancy for preventing gestational diabetes mellitus and hypertensive disorders: An umbrella review of randomised controlled trials and an updated meta-analysis.

OBJECTIVE: This study aimed to provide, through an umbrella review, an overview of the effect of single exercise interventions during pregnancy on gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP). Also, to update the current evidence through an updated meta-analysis. DESIGN: Umbrella review. SETTING: PubMed, EMBASE, Web of Science, Cochrane database of systematic reviews, Epistemonikos, SPORTDiscus, Clinicaltrials.gov, and PROSPERO register were searched from the database inception until August 2021. POPULATION: Peer-reviewed systematic reviews and meta-analyses of randomised controlled trials (RCTs) and RCTs samples. METHODS: Random-effects model was used to calculate relative risk with 95% confidence interval in the updated meta-analysis. The reference category was the groups that received usual prenatal care. AMSTAR 2 and the Cochrane Collaboration tool were used to assess the quality and GRADE approach was used to assess the overall certainly of evidence. MAIN OUTCOME MEASURES: GDM and HDP relative risk. RESULTS: Twenty-three systematic reviews and meta-analyses; and 63 RCTs were included. Single exercise interventions reduced the incidence of GDM and HDP in most systematic reviews and meta-analyses. Moreover, exercise interventions during pregnancy decrease the incidence of developing GDM and GH, particularly when they are supervised, have a low to moderate intensity level, and are initiated during the first trimester of pregnancy. CONCLUSION: Based on the findings, obstetric and physical exercise professionals could recommend exercise interventions during pregnancy as an effective strategy to improve maternal outcomes.

Effects of a low glycemic index or low glycemic load diet on pregnant women at high risk of gestational diabetes: A meta-analysis of randomized controlled trials.

AIMS: To evaluate the effect of low glycemic index or low glycemic load diets on maternal and neonatal outcomes at high risk of gestational diabetes mellitus (GDM). DATA SYNTHESIS: Several databases (PubMed, Cochrane Library, Web of Science, Embase, OVID, Clinical Trials. gov, China National Knowledge Infrastructure, China Biomedical Database, and Wanfang Database) were searched from January 1990 to January 2022 (updated to November 2022). Randomized controlled trials of low glycemic index diets interventions for women at high risk of GDM were included. From 2131 articles initially were screened, after eliminating duplicates, 1749 titles and abstracts were analyzed. 71 documents that met the inclusion criteria were selected and 3 documents were obtained through searching the reference lists. After reading the full text, 10 studies were retained. Two authors evaluated the studies, extracted data and conducted quality assessment independently. A total of 10 studies with 2304 patients met the inclusion criteria. Compared with the control group, a low glycemic index diet could control the range of weight gain (WMD -1.01, 95% CI -1.41 to -0.61), decrease the incidence of excessive weight gain (OR 0.69, 95% CI 0.54-0.87), lessen the incidence of large-for-gestational-age infants (OR 0.32, 95% CI 0.16-0.62) and reduce the incidence of preterm infants (OR 0.45, 95% CI 0.29-0.71). CONCLUSION: A low glycemic index or low glycemic load diet could control maternal weight gain, reduce the incidence of excessive weight gain, and decrease the incidence of large-for-gestational-age infants and preterm infants in group with high risk of GDM. PROSPERO: CRD42022322697.

Antenatal dietary supplementation with myo-inositol for preventing gestational diabetes.

BACKGROUND: Gestational diabetes with onset or first recognition during pregnancy is an increasing problem worldwide. Myo-inositol, an isomer of inositol, is a naturally occurring sugar commonly found in cereals, corn, legumes and meat. Myo-inositol is one of the intracellular mediators of the insulin signal and correlates with insulin sensitivity in type 2 diabetes. The potential beneficial effect of improving insulin sensitivity suggests that myo-inositol may be useful for women in preventing gestational diabetes. This is an update of a review first published in 2015. OBJECTIVES: To assess if antenatal dietary supplementation with myo-inositol is safe and effective, for the mother and fetus, in preventing gestational diabetes. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO ICTRP (17 March 2022) and the reference lists of retrieved studies. SELECTION CRITERIA: We included published and unpublished randomised controlled trials (RCTs) including cluster-RCTs and conference abstracts, assessing the effects of myo-inositol for the prevention of gestational diabetes in pregnant women. We included studies that compared any dose of myo-inositol, alone or in a combination preparation, with no treatment, placebo or another intervention. Quasi-randomised and cross-over trials were not eligible. We excluded women with pre-existing type 1 or type 2 diabetes. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, assessed risk of bias and extracted the data. We checked the data for accuracy. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included seven RCTs (one conducted in Ireland, six conducted in Italy) reporting on 1319 women who were 10 weeks to 24 weeks pregnant at the start of the studies. The studies had relatively small sample sizes and the overall risk of bias was low. For the primary maternal outcomes, meta-analysis showed that myo-inositol may reduce the incidence of gestational diabetes (risk ratio (RR) 0.53, 95% confidence interval (CI) 0.31 to 0.90; 6 studies, 1140 women) and hypertensive disorders of pregnancy (RR 0.34, 95% CI 0.19 to 0.61; 5 studies, 1052 women). However, the certainty of the evidence was low to very low. For the primary neonatal outcomes, only one study measured the risk of a large-for-gestational-age infant and found myo-inositol was associated with both appreciable benefit and harm (RR 1.40, 95% CI 0.65 to 3.02; 1 study, 234 infants; low-certainty evidence). None of the included studies reported on the other primary neonatal outcomes (perinatal mortality, mortality or morbidity composite). For the secondary maternal outcomes, we are unclear about the effect of myo-inositol on weight gain during pregnancy (mean difference (MD) -0.25 kilogram (kg), 95% CI -1.26 to 0.75 kg; 4 studies, 831 women) and perineal trauma (RR 4.0, 95% CI 0.45 to 35.25; 1 study, 234 women) because the evidence was assessed as being very low-certainty. Further, myo-inositol may result in little to no difference in caesarean section (RR 0.91, 95% CI 0.77 to 1.07; 4 studies, 829 women; low-certainty evidence). None of the included studies reported on the other secondary maternal outcomes (postnatal depression and the development of subsequent type 2 diabetes mellitus). For the secondary neonatal outcomes, meta-analysis showed no neonatal hypoglycaemia (RR 3.07, 95% CI 0.90 to 10.52; 4 studies; 671 infants; very low-certainty evidence). However, myo-inositol may be associated with a reduction in the incidence of preterm birth (RR 0.35, 95% CI 0.17 to 0.70; 4 studies; 829 infants). There were insufficient data for a number of maternal and neonatal secondary outcomes, and no data were reported for any of the long-term childhood or adulthood outcomes, or for health service utilisation outcomes. AUTHORS' CONCLUSIONS: Evidence from seven studies shows that antenatal dietary supplementation with myo-inositol during pregnancy may reduce the incidence of gestational diabetes, hypertensive disorders of pregnancy and preterm birth. Limited data suggest that supplementation with myo-inositol may not reduce the risk of a large-for-gestational-age infant.  The current evidence is based on small studies that were not powered to detect differences in outcomes such as perinatal mortality and serious infant morbidity. Six of the included studies were conducted in Italy and one in Ireland, which raises concerns about the lack of generalisability to other settings. There is evidence of inconsistency among doses of myo-inositol, the timing of administration and study population. As a result, we downgraded the certainty of the evidence for many outcomes to low or very low certainty. Further studies for this promising antenatal intervention for preventing gestational diabetes are encouraged and should include pregnant women of different ethnicities and varying risk factors. Myo-inositol at different doses, frequency and timing of administration, should be compared with placebo, diet and exercise, and pharmacological interventions. Long-term follow-up should be considered and outcomes should include potential harms, including adverse effects.

Effects of prenatal exercise on gestational weight gain, obstetric and neonatal outcomes: FitMum randomized controlled trial.

BACKGROUND: To investigate the effects of two different exercise interventions during pregnancy on gestational weight gain (GWG) and obstetric and neonatal outcomes compared to standard care. Additionally, we aimed to improve standardization of GWG measurements by developing a model to estimate GWG for a standardized pregnancy period of 40 weeks and 0 days accounting for individual differences in gestational age (GA) at delivery. METHODS: In a randomized controlled trial we compared the effects of structured supervised exercise training (EXE) three times per week throughout pregnancy versus motivational counselling on physical activity (MOT) seven times during pregnancy with standard care (CON) on GWG and obstetric and neonatal outcomes. Uniquely, to estimate GWG for a standardized pregnancy period, we developed a novel model to predict GWG based on longitudinally observed body weights during pregnancy and at admission for delivery. Observed weights were fitted to a mixed effects model that was used to predict maternal body weight and estimate GWG at different gestational ages. Obstetric and neonatal outcomes, among them gestational diabetes mellitus (GDM) and birth weight, were obtained after delivery. GWG and the investigated obstetric and neonatal outcomes are secondary outcomes of the randomized controlled trial, which might be underpowered to detect intervention effects on these outcomes. RESULTS: From 2018-2020, 219 healthy, inactive pregnant women with median pre-pregnancy BMI of 24.1 (21.8-28.7) kg/m2 were included at median GA 12.9 (9.4-13.9) weeks and randomized to EXE (n = 87), MOT (n = 87) or CON (n = 45). In total 178 (81%) completed the study. GWG at GA 40 weeks and 0 days did not differ between groups (CON: 14.9 kg [95% CI, 13.6;16.1]; EXE: 15.7 kg [14.7;16.7]; MOT: 15.0 kg [13.6;16.4], p = 0.538), neither did obstetric nor neonatal outcomes. For example, there were no differences between groups in the proportions of participants developing GDM (CON: 6%, EXE: 7%, MOT: 7%, p = 1.000) or in birth weight (CON: 3630 (3024-3899), EXE: 3768 (3410-4069), MOT: 3665 (3266-3880), p = 0.083). CONCLUSIONS: Neither structured supervised exercise training nor motivational counselling on physical activity during pregnancy affected GWG or obstetric and neonatal outcomes compared to standard care. TRIAL REGISTRATION: ClinicalTrials.gov; NCT03679130; 20/09/2018.

Development and feasibility of a theory-guided and evidence-based physical activity intervention in pregnant women with high risk for gestational diabetes mellitus: a pilot clinical trial.

BACKGROUND: Physical activity has been utilized as an effective strategy to prevent gestational diabetes mellitus (GDM). However, most pregnant women with high risk for GDM did not achieve the recommended physical activity level. Furthermore, relevant physical activity protocols have varied without theory-guided and evidence-based tailored to pregnant women with high risk for GDM. This study aimed to develop and pilot test a theory-guided and evidence-based physical activity intervention protocol for pregnant women with high risk for GDM. METHODS: The study design was guided by the Medical Research Council Framework for Developing and Evaluating Complex Intervention (the MRC framework). The preliminary protocol for physical activity intervention was developed based on self-efficacy theory, research evidence identified from systematic reviews and clinic trials, stakeholder engagement, context, and economic considerations. The preliminary intervention protocol was validated through a content validity study by an expert panel of 10 experts. A single-blinded randomized controlled trial (RCT) was designed to test the feasibility and acceptability of the intervention. RESULTS: The validity of the preliminary intervention protocol was excellent as consensus was achieved. The final 13 sessions of self-efficacy enhancing physical activity intervention protocol were developed, including knowledge education, exercise clinic visits and video, and group discussions with face-to-face and online blended sessions. In the feasibility study, 34 pregnant women with high risk for GDM were randomized for the intervention (n = 17) or the control group (n = 17). The recruitment and retention rates were 82.9% and 58.9%, respectively. Women in the intervention group had a lower incidence of GDM (26.7% vs. 36.5%) than the control group (P >0.05). All participants were satisfied with the intervention and agreed that the intervention was helpful. CONCLUSIONS: The developed self-efficacy-enhancing physical activity intervention is a feasible and acceptable intervention for enhancing physical activity among pregnant women with high risk for GDM and is ready to be tested in a more extensive RCT study. TRIAL REGISTRATION: The study was registered on 4 February 2022 (ChiCTR2200056355) by the Chinese Clini Trial Registry (CHiCTR).