Carbohydrates, glycemic index, and pregnancy outcomes in gestational diabetes

Physical activity during pregnancy and the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis

BACKGROUND

Previous research has indicated the inverse association between physical activity (PA) and gestational diabetes mellitus (GDM). However, the dose-response relationship currently remains undetermined. This study aims to explore the dose-response relationship between PA during the first and second trimesters of pregnancy and GDM risk.

METHODS

Studies on the relationship between PA during pregnancy and GDM risk published before April 25, 2023, were searched for in six databases. According to the inclusion and exclusion criteria, all literature was screened for eligibility. The Newcastle-Ottawa Scale (NOS) was used to assess risk of bias. Publication bias was examined using funnel plots, Begg's and Egger's tests, as well as trim-and-fill analysis. We harmonized exposure estimates of PA during pregnancy to the common unit of the metabolic equivalent of task (MET)-h/week. Restricted cubic splines were used to model the dose-response relationship. The criteria from the World Cancer Research Fund were used to assess the certainty of evidence across outcomes. All analyses were performed using Stata 15.1.

RESULTS

The results indicated that in contrast with the lowest level of PA, promoting the highest PA level lowers the risk of GDM by 36% (RR = 0.64, 95%CI: 0.53 ~ 0.78). We found a curvilinear dose-response association between PA during the first trimester and incident GDM (Pnonlinearity = 0.012). Compared to inactive pregnant women, for those who achieved the guidelines-suggested minimum level (10 MET-h/week) of PA during the first trimester, the GDM risk was decreased by 13% (RR = 0.87, 95%CI: 0.79 ~ 0.96). A linear relationship was found between PA during the second trimester and the GDM risk (Pnonlinearity = 0.276). The results with a restricted cubic spline model suggested that pregnant women who accumulate 10 MET-h/week have a 1% reduced risk of GDM compared to completely inactive individuals. Twice (20 MET-h/week) or a higher amount of PA (50 MET-h/week) contributed to further reductions in GDM risk.

CONCLUSION

There is a dose-response relationship between higher levels of PA in both the first and second trimesters and reduced risk of GDM; the relationship is stronger in the first trimester. Increasing PA during pregnancy can prevent the development of GDM.

PROSPERO REGISTRATION NUMBER

CRD42023420564.

Low-Protein Infant Formula and Obesity Risk

Infant formulas have been designed to mimic human milk for infants who cannot be breastfed. The overall goal is to establish similar functional outcomes to assure optimal growth, development, maturation of the immune system, and programming of the metabolic system. However, after decades of improving infant formula, growth patterns and body composition development are still different in formula-fed infants compared to breastfed infants, which could contribute to an increased risk of obesity among formula-fed infants. It has been hypothesized that the lower protein concentration of breast milk compared to infant formula influences infants’ growth and body composition. Thus, several trials in formula-fed infants with different protein intake levels have been performed to test this hypothesis. In this review, we discuss the current evidence on low-protein infant formula and obesity risk, including future perspectives and implications.

Associations of dietary glycemic index and load during pregnancy with blood pressure, placental hemodynamic parameters and the risk of gestational hypertensive disorders

Purpose

The aim of this study was to examine the associations of dietary glycemic index and load with gestational blood pressure, placental hemodynamic parameters and the risk of gestational hypertensive disorders.

Methods

In a population-based cohort among 3378 pregnant Dutch women, dietary glycemic index and load were assessed from food frequency questionnaires at median 13.4 (95% range 9.9–22.9) weeks gestation. Blood pressure was measured in early-, mid- and late-pregnancy. Placental hemodynamic parameters were measured in mid- and late-pregnancy by ultrasound. Data on gestational hypertensive disorders was acquired from medical records.

Results

Mean dietary glycemic index (SD) was 58 (3) and mean dietary glycemic load (SD) was 155 (47). Dietary glycemic index was not associated with blood pressure, placental hemodynamic parameters and the risk of gestational hypertensive disorders. Higher dietary glycemic load SDS was associated with a higher diastolic blood pressure in early-pregnancy, remaining after adjustment for socio-demographic and lifestyle factors ((0.98 (95% CI 0.35–1.61) mmHg per SDS increase in glycemic load). No other associations of glycemic load with blood pressure or placental hemodynamic parameters and the risk of gestational hypertensive disorders were present. No significant associations of dietary glycemic index and load quartiles with longitudinal blood pressure patterns from early to late-pregnancy were present.

Conclusion

Within this low-risk pregnant population, we did not find consistent associations of dietary glycemic index and load with blood pressure, placental hemodynamic parameters and the risk of gestational hypertensive disorders. Further studies need to assess whether the effects on gestational hemodynamic adaptations are more pronounced among high-risk women with an impaired glucose metabolism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02670-5.

Impact of dietary counseling on the perception of diet in patients with gestational diabetes mellitus

AIMS/INTRODUCTION

Medical nutrition therapy is the cornerstone of gestational diabetes mellitus (GDM) treatment. Patients with GDM should receive dietary counseling regarding diet and exercise.

MATERIALS AND METHODS

To study patients' perception level of diet and their level of understanding after dietary counseling, we analyzed 225 reports of dietary counseling of patients with GDM prepared by dieticians. We also assessed the patients' level of understanding after dietary counseling by asking questions regarding the counseling content. The answers to the questions were aggregated, and substantially similar answers were grouped and categorized.

RESULTS

The dieticians' suggestions were well understood by the patients. Moreover, the patients also identified their previous incorrect eating habits, such as excessive carbohydrate restriction or inappropriate fruit intake. Although distributed frequent meals were recommended by the dieticians, few patients actually practiced this for various reasons. Some patients were apparently influenced by dietary information from the mass media.

CONCLUSION

Dietary counseling was regarded as helpful and acceptable to most patients with GDM in our hospital, and many suggestions were recognized as informative for modification of previous dietary habits. By providing the results of the questionnaire survey to the dieticians, they can improve the quality of their counseling, which is expected to result in better individual care of the patients.

Associations of maternal early-pregnancy dietary glycemic index with childhood general, abdominal and ectopic fat accumulation

Background & aims

Maternal hyperglycemia during pregnancy is an important risk factor for childhood adiposity. Maternal dietary glycemic index during pregnancy directly influences maternal and fetal glucose concentrations. We examined the associations of maternal early-pregnancy dietary glycemic index with offspring general, abdominal and ectopic fat accumulation among normal weight and overweight or obese pregnant women and their offspring.

Methods

In a population-based cohort study among 2488 Dutch pregnant women and their children, we assessed maternal dietary glycemic index by food frequency questionnaire at median 13.4 (95% range 10.7; 21.1) weeks gestation. Dietary glycemic index was used continuously and categorized into low (≤55), normal (56–69) and high (≥70) glycemic index diet. We measured offspring BMI, total fat mass and android/gynoid fat mass ratio by DXA, and visceral fat mass and liver fat fraction by MRI at 10 years.

Results

No associations of maternal early-pregnancy dietary glycemic index with offspring adiposity were present among normal weight women and their children. Among overweight and obese women and their children, 1-Standard Deviation Score (SDS) increase in maternal early-pregnancy dietary glycemic index was associated with higher childhood BMI (0.10 SDS, 95% Confidence Interval (CI) 0.01; 0.19), total fat mass index (0.13 SDS, 95% CI 0.05; 0.22), visceral fat mass index (0.19 SDS, 95% CI 0.07; 0.32) and tended to be associated with a higher android/gynoid fat mass ratio (0.09 SDS, 95% CI −0.01; 0.19) and higher risk of childhood overweight (Odds Ratio (OR) 1.20, 95% CI 0.97; 1.48). Overweight and obese women consuming an early-pregnancy low-glycemic index diet, as compared to an early-pregnancy normal-glycemic index diet, had children with lower BMI, total fat mass index, visceral fat mass index and android/gynoid fat mass ratio at 10 years (p-values<0.05). No women consumed a high-glycemic index diet. No associations were explained by maternal socio-economic, lifestyle and dietary characteristics, birth or childhood characteristics. No associations with liver fat fraction were present.

Conclusions

In overweight or obese women and their children, a higher maternal early-pregnancy dietary glycemic index is associated with childhood general, abdominal and visceral fat accumulation, but not with liver fat. Intervention studies among overweight and obese pregnant women may need to target the dietary glycemic index to prevent childhood adiposity.

Searching for Utopia, the Challenge of Standardized Medical Nutrition Therapy Prescription in Gestational Diabetes Mellitus Management: A Critical Review

Gestational diabetes mellitus (GDM) is a common pregnancy disorder and the incidence is increasing worldwide. GDM is associated with adverse maternal outcomes which may be reduced with proper management. Lifestyle modification in the form of medical nutrition therapy and physical activity, as well as self-monitoring of blood glucose levels, is the cornerstone of GDM management. Inevitably, the search for the "ultimate" diet prescription has been ongoing. Identifying the amount and type of carbohydrate to maintain blood glucose levels below targets while balancing the nutritional requirements of pregnancy and achieving gestational weight gain within recommendations is challenging. Recent developments in the area of the gut microbiota and its impact on glycemic response add another layer of complexity to the success of medical nutrition therapy. This review critically explores the challenges to dietary prescription for GDM and why utopia may never be found.

Nutrition for Gestational Diabetes-Progress and Potential

Gestational diabetes (GDM), traditionally defined as any form of glucose intolerance first detected in pregnancy [...].

Maternal early pregnancy dietary glycemic index and load, fetal growth, and the risk of adverse birth outcomes

Purpose

Maternal hyperglycemia is associated with adverse birth outcomes. Maternal dietary glycemic index and load influence postprandial glucose concentrations. We examined the associations of maternal early pregnancy dietary glycemic index and load with fetal growth and risks of adverse birth outcomes.

Methods

In a population-based cohort study of 3471 pregnant Dutch women, we assessed dietary glycemic index and load using a food frequency questionnaire at median 13.4 (95% range 10.6; 21.2) weeks gestation. We measured fetal growth in mid- and late-pregnancy by ultrasound and obtained birth outcomes from medical records.

Results

Mean maternal early pregnancy dietary glycemic index and load were 57.7 (SD 3.3, 95% range 52.8; 63.5) and 155 (SD 47, 95% range 87; 243), respectively. Maternal early pregnancy dietary glycemic index was not associated with fetal growth parameters. A higher maternal early pregnancy dietary glycemic load was associated with a higher fetal abdominal circumference and estimated fetal weight in late-pregnancy (p values < 0.05), but not with mid-pregnancy or birth growth characteristics. A higher maternal early pregnancy dietary glycemic index was associated with a lower risk of a large-for-gestational-age infant (p value < 0.05). Maternal early pregnancy glycemic index and load were not associated with other adverse birth outcomes.

Conclusion

Among pregnant women without an impaired glucose metabolism, a higher early pregnancy dietary glycemic load was associated with higher late-pregnancy fetal abdominal circumference and estimated fetal weight. No consistent associations of maternal dietary glycemic index and load with growth parameters in mid-pregnancy and at birth were present. A higher glycemic index was associated with a lower risk of a large-for-gestational-age infant.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02327-9) contains supplementary material, which is available to authorized users.

Association of a plant-based dietary pattern in relation to gestational diabetes mellitus

AIM

The prevalence of gestational diabetes mellitus (GDM), which has adverse effects on mothers and their offspring, is increasing worldwide. The role of a plant-based dietary pattern as a determinant of GDM is not well understood. Therefore, we examined the association between plant-based dietary patterns and the risk of GDM.

METHODS

We enrolled 460 pregnant women in this case-control study, of them 200 were cases and 260 were controls. Dietary intake of participants was evaluated using three 24-hour dietary records. Adherence to the plant-based dietary patterns was scored using three indices of the overall plant-based dietary index (PDI), healthy plant-based diet (hPDI) and unhealthy plant-based diet index (uPDI). The risk of GDM was compared across tertiles of PDI, hPDI and uPDI.

RESULTS

After multivariable adjustment, we demonstrated that the high PDI score was inversely associated with risk of GDM (OR = 0.47; 95% CI: 0.28-0.78, P = 0.004), but there was no significant association between hPDI (OR = 1.03; 95% CI: 0.64-1.65, P = 0.884) or uPDI (OR = 1.65; 95% CI: 0.98-2.78, P = 0.06) and GDM risk.

CONCLUSIONS

We found that following an overall plant-based diet was associated with lower risk of GDM. Future studies are warranted with longitudinal designs to confirm these findings.

Gestational Diabetes: Underpinning Principles, Surveillance, and Management

Gestational diabetes mellitus (GDM) is carbohydrate intolerance resulting in hyperglycemia with onset during pregnancy. The article aims to provide clinicians with a working framework to minimize maternal and neonatal morbidity. Landmark historical and recent data are reviewed and presented to provide clinicians with a quick, easy reference for recognition and management of GDM. Data presented tie in insights with underlying pathophysiologic processes leading to GDM. Screening and diagnostic thresholds are discussed along with management upon diagnosis. Good clinical practice regarding screening, diagnosis, and management of GDM effectively reduces risk and improves outcomes of women and fetuses in affected pregnancies.

Influence of low-glycemic index diet for gestational diabetes: a meta-analysis of randomized controlled trials

Background: Low-glycemic index (GI) diet might be beneficial for gestational diabetes. However, the results remained controversial. We conducted a systematic review and meta-analysis to explore the influence of low-GI diet on gestational diabetes.Methods: PubMed, EMbase, Web of Science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of low-GI diet on gestational diabetes were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. This meta-analysis was performed using the random-effect model.Results: Six RCTs involving 532 patients were included in the meta-analysis. Overall, compared with a control intervention in gestational diabetes, low-GI diet was found to significantly reduce 2 h postprandial glucose (Std. MD = -0.46; 95% CI = -0.82 to -0.10; p = .01), but demonstrated no substantial influence on fasting plasma glucose (Std. MD = -0.24; 95% CI = -0.72 to 0.24; p = .33), HbA1c (Std. MD = 0.01; 95% CI = -0.29 to 0.31; p = .94), birth weight (Std. MD = -0.17; 95% CI = -0.41 to 0.06; p = .15), macrosomia (Std. MD = 0.45; 95% CI = 0.16 to 1.30; p = .14) and insulin requirement (Std. MD = 0.91; 95% CI = 0.68 to 1.22; p = .55).Conclusions: Compared with control intervention in gestational diabetes, low-GI diet was found to significantly decrease 2 h postprandial glucose, but showed no notable impact on fasting plasma glucose, HbA1c, birth weight, macrosomia, and insulin requirement.

Feeding a slowly digestible carbohydrate diet during pregnancy of insulin-resistant rats prevents the excess of adipogenesis in their offspring

An obesogenic environment during pregnancy has been shown to increase the risk of dysregulation on adipogenesis and insulin resistance in the offspring. Being essential for the growing fetus, glucose supply is guaranteed by a number of modifications in the mother's metabolism, and thus, glucose control during pregnancy especially among obese or diabetic women is paramount to prevent adverse consequences in their children. Besides the election of low-glycemic-index carbohydrates, the rate of carbohydrate digestion could be relevant to keep a good glucose control. In the present study, we compared the effects of two high-fat diets with similar glycemic load but different rates of carbohydrate digestion given to pregnant insulin-resistant rats. After birth, all animals were fed a standard diet until age 14 weeks. We analyzed offspring body composition, plasma and adipocyte lipidomics, lipid metabolism in adipose tissue and insulin sensitivity. Those animals whose mothers were fed the rapid-digesting carbohydrate diet exhibited an excessive adipogenesis. Thus, these animals showed a marked lipidemia, increased lipid synthesis in the adipose tissue and reduced glucose transporter amount in the adipose. On the contrary, those animals whose mothers were fed the slow-digesting carbohydrate diet showed a profile in the measured parameters closer to that of the offspring of healthy mothers. These results support the hypothesis that not only glycemic index but the rate of carbohydrate digestion during gestation may be critical to regulate the programming of adipogenesis in the offspring.

Improving pregnancy outcome in obese women: the UK Pregnancies Better Eating and Activity randomised controlled Trial

Background

Obesity in pregnancy is associated with insulin resistance, which underpins many common complications including gestational diabetes mellitus (GDM) and fetal macrosomia.

Objectives

To assess the effect of a complex behavioural intervention based on diet and physical activity (PA) on the risk of GDM and delivery of a large-for-gestational age (LGA) infant.

Design

Three phases: (1) the development phase, (2) the pilot study and (3) a multicentre randomised controlled trial (RCT) comparing a behavioural intervention to improve glycaemic control with standard antenatal care in obese pregnant women. A cost–utility analysis was undertaken to estimate the cost-effectiveness of the health training (intervention) over and above standard care (control).

Setting

Pilot study: antenatal clinics in four inner-city UK hospitals. RCT: eight antenatal clinics in eight UK inner-city hospitals.

Participants

Women were eligible for inclusion if they had a body mass index of ≥ 30 kg/m2, were pregnant with a single fetus and at 15+0to 18+6weeks’ gestation, were able to give written informed consent and were without predefined disorders.

Intervention

The intervention comprised an initial session with a health trainer, followed by eight weekly sessions. Dietary advice recommended foods with a low dietary glycaemic index, avoidance of sugar-sweetened beverages and reduced saturated fats. Women were encouraged to increase daily PA.

Main outcome measures

Development phase: intervention development, acceptability and optimal approach for delivery. Pilot study: change in dietary and PA behaviours at 28 weeks’ gestation. RCT: the primary outcome of the RCT was, for the mother, GDM [as measured by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG)’s diagnostic criteria] and, for the infant, LGA delivery (i.e. customised birthweight ≥ 90th centile for gestational age).

Results

Development phase: following a literature meta-analysis, a study of dietary intention questionnaires and semistructured interviews, an intervention based on behavioural science was developed that incorporated optimal and acceptable methods for delivery. Pilot study: the pilot study demonstrated improvement in dietary behaviours in the intervention compared with the standard care arm but no increase in objectively measured PA. Process evaluation demonstrated feasibility and general acceptability. RCT: the RCT showed no effect of the intervention on GDM in obese pregnant women or the number of deliveries of LGA infants. There was a reduction in dietary glycaemic load (GL) and reduced saturated fat intake, an increase in PA and a modest reduction in gestational weight gain, all secondary outcomes. Lower than expected was the number of LGA infant deliveries in all women, which suggested that universal screening for GDM with IADPSG’s diagnostic criteria, and subsequent treatment, may reduce the number of deliveries of LGA infants. According to the cost–utility analysis, the estimated probability that the UK Pregnancies Better Eating and Activity Trial (UPBEAT) behavioural intervention is cost-effective at the £30,000/quality-adjusted life-year willingness-to-pay threshold was 1%.

Limitations

Included the high refusal rate for participation and self-reported assessment of diet and PA.

Conclusions

The UPBEAT intervention, an intense theoretically based intervention in obese pregnant women, did not reduce the risk of GDM in women or the number of LGA infant deliveries, despite successfully reducing the dietary GL. Based on total cost to the NHS provider and health gains, the UPBEAT intervention provided no supporting evidence to suggest that the intervention represents value for money based on the National Institute for Health and Care Excellence benchmarks for cost-effectiveness.

Future work

Alternative strategies for reducing the risk of GDM in obese pregnant women and the number of LGA infant deliveries should be considered, including development of clinically effective interventions to prevent obesity in women of reproductive age, of clinically effective interventions to reduce weight retention following pregnancy and of risk stratification tools in early pregnancy.

Trial registration

Current Controlled Trials ISRCTN89971375 and UK Clinical Research Network Portfolio 5035.

Funding

This project was funded by the NIHR Programme Grant for Applied Research programme and will be published in full inProgramme Grants for Applied Research, Vol. 5, No. 10. See the NIHR journals library website for further project information. Contributions to funding were also provided by the Chief Scientist Office CZB/4/680, Scottish Government Health Directorates, Edinburgh; Guys and St Thomas’ Charity, Tommy’s Charity (Lucilla Poston, Annette L Briley, Paul T Seed) and the NIHR Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London, UK and the Academy of Finland, Finland. Keith M Godfrey was supported by the National Institute for Health Research through the NIHR Southampton Biomedical Research Centre. Lucilla Poston and Keith M Godfrey were supported by the European Union’s Seventh Framework Programme (FP7/2007-2013), project EarlyNutrition under grant agreement number 289346.

Current Concepts of Maternal Nutrition

BACKGROUND

A nutrient-rich maternal diet before and during pregnancy is associated with improved fetal health, more appropriate birth weight, and increased rates of maternal and infant survival. Physicians need a better understanding of the role of diet in shaping fetal outcomes. Given this background, we reviewed and summarized articles on maternal nutrition found in MEDLINE since 1981, written in English, and limited to human subjects.

FOR THE OFFSPRING

Maternal diets high in sugar and fat lead to an increased incidence of metabolic syndrome, diabetes, and cardiovascular disease later in life. Folic acid should be supplemented prior to conception and continued through at least the first 28 days of fetal life to prevent neural tube defects, and vitamin C should be given to women who smoke to lower the incidence of asthma and wheezing in the children. Iodine deficiency is increasing, and iodine should be included in prenatal supplements. If the maternal hemoglobin is 7 g/dL or more, there is no evidence that iron supplementation is needed. Fish intake during pregnancy is protective against atopic outcomes, whereas high-meat diets contribute to elevated adult blood pressure and hypersecretion of cortisol.

FOR THE MOTHER

Calcium supplementation lowers the risk of preeclampsia and hypertensive disease in pregnancy.

CONCLUSIONS

Given the limits of our current knowledge, a diet rich in whole grains, fruits, vegetables, and selected fish is desirable for the best outcomes. Diets high in sugar and fat lead to higher rates of diabetes, metabolic syndrome, and cardiovascular disease. Folic acid, iodine, and calcium in all pregnant women and vitamin C in smokers are the only supplements so far shown to be of value for routine use. The physician treating a pregnant woman should be ready to advise a healthy diet for the benefit of the fetus.

Dietary glycaemic index and glycaemic load among Australian children and adolescents: results from the 2011–2012 Australian Health Survey

This study aimed to examine the dietary glycaemic index (GI) and glycaemic load (GL) of Australian children and adolescents, as well as the major food groups contributing to GL, in the recent 2011–2012 Australian Health Survey. Plausible food intake data from 1876 children and adolescents (51 % boys), collected using a multiple-pass 24-h recall, were analysed. The GI of foods was assigned based on a step-wise published method using values from common GI databases. Descriptive statistics were calculated for dietary GI, GL and contribution to GL by food groups, stratified by age group and sex. Linear regression was used to test for trends across age groups for BMI, dietary GI and GL, and intakes of energy, nutrients and food groups. Pearson’s χ2 test was used to test for differences between age groups for categorical subject characteristic variables. Mean dietary GI and GL of participants were 55·5 (sd 5·3) and 137·4 (sd 50·8), respectively. The main contributors to dietary GL were starchy foods: breads, cereal-based dishes, breakfast cereals, flours, grains and potatoes accounted for 41 % of total GL. Sweetened beverages, fruit and vegetable juices/drinks, cake-type desserts and sweet biscuits contributed 15 %. No significant difference (at P<0·001) was observed between sexes. In conclusion, Australian children and adolescents appear to consume diets with a lower GI than European children. Exchanging high-GI foods for low-GI alternatives within core and non-core foods may improve diet quality of Australian children and adolescents.

Effects of Low Glycemic Index Diets on Gestational Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Clinical Trials

Studies of the effects of low glycemic index (LGI) diets on gestational diabetes mellitus (GDM) have reported conflicting findings.The aim of the study was to evaluate the results of randomized controlled trials (RCTs) that investigated the effects of LGI diets with and without added dietary fiber (DF) on maternal and neonatal outcomes in GDM patients.We searched the MEDLINE, EMBASE, EBSCO, Springer, Ovid, and Cochrane Library databases for studies of the effects of LGI diets in GDM patients. We performed a meta-analysis of the effects of the LGI diets with and without added dietary fiber (DF) on GDM outcomes. Risk ratios (RR) and 95% confidence intervals (CIs) were calculated using random- and fixed-effects models.Five RCTs involving 302 participants were included in our meta-analysis. No statistically significant differences in the risks of cesarean section delivery, large for gestational age, and small for gestational age were observed. The risk of macrosomia in the LGI groups was significantly lower (RR = 0.27; 95% CI: 0.10-0.71; P = 0.008) than that in the control groups. Our subgroup analysis of the effects of DF showed that LGI diets with an increased level of DF, relative to the control diet, reduced the risk of macrosomia beyond that of the LGI diets alone (RR: 0.17 vs 0.47, respectively). The subgroup analysis also showed that LGI diets in which the level of DF was approximately equivalent to that in the control diets significantly reduced the risk of insulin usage (RR = 0.69; 95% CI: 0.52-0.92; P = 0.01).The LGI diets reduced the risk of macrosomia in GDM patients, and LGI diets with added DF reduced the risk of macrosomia further. The LGI diets with levels of DF approximately equivalent to that in the control diets reduced the risk of insulin usage in GDM patients.

Role of Medical Nutrition Therapy in the Management of Gestational Diabetes Mellitus

Medical nutrition therapy (MNT) plays an important role in the management of gestational diabetes mellitus (GDM), and accordingly, it has a significant impact on women and newborns. The primary objective of MNT is to ensure adequate pregnancy weight gain and fetus growth while maintaining euglycemia and avoiding ketones. However, the optimal diet (energy content, macronutrient distribution, its quality and amount, among others) remains an outstanding question. Overall, the nutritional requirements of GDM are similar for all pregnancies, but special attention is paid to carbohydrates. Despite the classical intervention of restricting carbohydrates, the latest evidence, although limited, seems to favor a low-glycemic index diet. There is general agreement in the literature about caloric restrictions in the case of being overweight or obese. Randomized controlled trials are necessary to investigate the optimal MNT for GDM; this knowledge could yield health benefits and cost savings.

A low glycemic index staple diet reduces postprandial glucose values in Asian women with gestational diabetes mellitus

BACKGROUND

A low glycemic index (GI) diet is beneficial for glucose control in patients with diabetes mellitus. This study aimed to investigate the influence of a low-GI diet on postprandial glucose levels in women with gestational diabetes mellitus (GDM).

METHODS

Pregnant women with GDM were randomized to receive a normal diabetic control diet or a low-GI staple diet for 5 days. A low-GI staple food was used to replace rice in lunch and dinner for the low-GI staple diet group, whereas the total energy and carbohydrate levels remained equal in both groups. Fasting and postprandial glucose levels were determined daily.

RESULTS

A total of 140 pregnant women with GDM were included in the study, including 66 in the low-GI staple diet group and 74 in the normal diabetic diet control group. No differences existed in baseline characteristics between the 2 groups (all P > 0.05). After dietary intervention, glucose levels were significantly reduced in the low-GI staple diet group (all P < 0.01) and the control group (all P < 0.008). Postintervention glucose values after breakfast, lunch, and dinner were significantly reduced in the treatment group compared with those in the control group (all P < 0.05). The percentage changes from baseline of all glucose values were significantly greater in the treatment group than in the control group (all P < 0.05).

CONCLUSIONS

A low-GI staple diet significantly reduces postprandial glucose levels in women with GDM.

Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes

OBJECTIVE

Diet is the cornerstone treatment of patients with gestational diabetes mellitus (GDM), but its role in maternal and newborn outcomes has been scarcely studied. The purpose of this study was to analyze the efficacy of dietary interventions on maternal or newborn outcomes in patients with GDM.

RESEARCH DESIGN AND METHODS

A systematic review and meta-analysis of randomized clinical trials (RCTs) of dietary intervention in GDM or pregnancy with hyperglycemia was performed. MEDLINE, Embase, ClinicalTrials.gov, Cochrane, and Scopus were searched through to March 2014. The main evaluated maternal outcomes were proportion of patients using insulin and proportion of cesarean delivery; the newborn outcomes were proportion of macrosomia and hypoglycemia and newborn weight.

RESULTS

From 1,170 studies, nine RCTs, including 884 women aged 31.5 years (28.7-33.2) with 27.4 weeks (24.1-30.3) of gestation, were eligible. We divided the RCTs according to the type of dietary intervention: low glycemic index (GI) (n = 4; 257 patients), total energy restriction (n = 2; 425 patients), low carbohydrates (n = 2; 182 patients), and others (n = 1; 20 patients). Diet with low GI reduced the proportion of patients who used insulin (relative risk 0.767 [95% CI 0.597, 0.986]; P = 0.039) and the newborn birth weight (weight mean differences -161.9 g [95% CI -246.4, -77.4]; P = 0.000) as compared with control diet. Total restriction and low carbohydrate diets did not change either maternal or newborn outcomes.

CONCLUSIONS

A low GI diet was associated with less frequent insulin use and lower birth weight than control diets, suggesting that it is the most appropriate dietary intervention to be prescribed to patients with GDM.

Intensive low-glycaemic-load dietary intervention for the management of glycaemia and serum lipids among women with gestational diabetes: a randomized control trial

OBJECTIVE

The present study aimed to compare the effects of a general dietary intervention and an intervention with low glycaemic load (GL) on glycaemic control, blood lipid metabolism and pregnancy outcomes in women with gestational diabetes mellitus.

DESIGN

Participants were randomly assigned to two groups, receiving either an individualized general dietary intervention (Control group) or an intensive low-GL intervention (Low-GL group) every two weeks, from 24-26 weeks of gestation to delivery.

SETTING

The Center of Maternal Primary Care in Guangdong General Hospital, China.

SUBJECTS

Ninety-five women with gestational diabetes mellitus were enrolled from June 2008 to July 2009.

RESULTS

After the intervention, both groups significantly decreased their dietary intakes of energy, fat and carbohydrate. The Low-GL group had significantly lower values for GL (122 v. 136) and glycaemic index (50 v. 54) but greater dietary fibre intake (33 v. 29 g/d) than did the Control group (all P<0·01). Significantly greater decreases in fasting plasma glucose (-0·33 v. -0·02 mmol/l, P<0·01) and 2 h postprandial glucose (-2·98 v. -2·51 mmol/l, P<0·01), significantly lower increases in total cholesterol (0·12 v. 0·23 mmol/l) and TAG (0·41 v. 0·56 mmol/l) and a significantly lower decrease in HDL cholesterol (-0·01 v. -0·11 mmol/l) were also observed in the Low-GL group compared with the Control group (all P<0·05). There were no significant differences in body weight gain, birth weight or other maternal-fetal perinatal outcomes between the two groups.

CONCLUSIONS

The low-GL targeted dietary intervention outperformed the general dietary intervention in glycaemic control and the improvement of blood lipid levels in women with gestational diabetes mellitus.

Early pregnancy urinary biomarkers of fatty acid and carbohydrate metabolism in pregnancies complicated by gestational diabetes

AIMS

Alterations in organic acid biomarkers from fatty acid and carbohydrate metabolism have been documented in type 2 diabetes patients. However, their association with gestational diabetes mellitus (GDM) is largely unknown.

METHODS

Participants were 25 GDM cases and 25 non-GDM controls. Biomarkers of fatty acid (adipate, suberate and ethylmalonate) and carbohydrate (pyruvate, l-lactate and β-hydroxybutyrate) metabolism were measured in maternal urine samples collected in early pregnancy (17 weeks) using liquid chromatography-mass spectrometry methods. Logistic regression were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

GDM cases and controls differed in median urinary concentrations of ethylmalonate (3.0 vs. 2.3μg/mg creatinine), pyruvate (7.4 vs. 2.1μg/mg creatinine), and adipate (4.6 vs. 7.3μg/mg creatinine) (all p-values <0.05). Women in the highest tertile for ethylmalonate or pyruvate concentrations had 11.4-fold (95%CI 1.10-117.48) and 3.27-fold (95%CI 0.72-14.79) increased risk of GDM compared with women in the lowest tertile for ethylmalonate and pyruvate concentrations, respectively. Women in the highest tertile for adipate concentrations, compared with women in the lowest tertile, had an 86% reduction in GDM risk (95%CI 0.02-0.97).

CONCLUSIONS

These preliminary findings underscore the importance of altered fatty acid and carbohydrate metabolism in the pathogenesis of GDM.

Diet and carbohydrate food knowledge of multi-ethnic women: a comparative analysis of pregnant women with and without Gestational Diabetes Mellitus

Background

Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Carbohydrate is the primary nutrient affecting postprandial blood glucose levels. Hence, knowledge of food containing carbohydrates can assist women with GDM optimize glycemic control. Despite that, there is a paucity of research on carbohydrate-related knowledge of women with GDM. The United Arab Emirates (UAE) has one of the highest prevalence of diabetes (19.2%) in the world. This study compared diet and knowledge of carbohydrate-containing foods among pregnant women with and without GDM in the UAE.

Methods

The sample consisted of multi-ethnic women with GDM (n = 94) and a control group of healthy pregnant women (n = 90) attending prenatal clinics in three hospitals in Al Ain, UAE. Data were collected using a questionnaire and a 24-hour recall. Knowledge of food sources of carbohydrate, dietary patterns, and nutrient intakes of the two groups were compared.

Results

There were no significant differences in the mean knowledge score of food sources of carbohydrate between women with GDM and that of pregnant women without GDM. Similarly, there were no significant differences in energy and nutrient intakes between the two groups with the exception of percent energy from protein. Women with GDM reported significantly lower intake of fruits and fruit juices (P = 0.012) and higher consumption of milk and yogurt (P = 0.004) compared to that of women without GDM. Twenty-two percent of women with GDM indicated they never visited a dietitian for counseling while 65% reported they visited a dietitian only once or twice during the pregnancy. Predictors of carbohydrate knowledge score were perceived knowledge of diet and GDM and parity among women with GDM and parity and educational level among those without GDM.

Conclusion

The results of the study highlight the urgent need to provide nutrition education for women with GDM in the UAE.

Developing a complex intervention for diet and activity behaviour change in obese pregnant women (the UPBEAT trial); assessment of behavioural change and process evaluation in a pilot randomised controlled trial

BACKGROUND

Complex interventions in obese pregnant women should be theoretically based, feasible and shown to demonstrate anticipated behavioural change prior to inception of large randomised controlled trials (RCTs). The aim was to determine if a) a complex intervention in obese pregnant women leads to anticipated changes in diet and physical activity behaviours, and b) to refine the intervention protocol through process evaluation of intervention fidelity.

METHODS

We undertook a pilot RCT of a complex intervention in obese pregnant women, comparing routine antenatal care with an intervention to reduce dietary glycaemic load and saturated fat intake, and increase physical activity. Subjects included 183 obese pregnant women (mean BMI 36.3 kg/m2).

RESULTS

Compared to women in the control arm, women in the intervention arm had a significant reduction in dietary glycaemic load (33 points, 95% CI -47 to -20), (p < 0.001) and saturated fat intake (-1.6% energy, 95% CI -2.8 to -0. 3) at 28 weeks' gestation. Objectively measured physical activity did not change. Physical discomfort and sustained barriers to physical activity were common at 28 weeks' gestation. Process evaluation identified barriers to recruitment, group attendance and compliance, leading to modification of intervention delivery.

CONCLUSIONS

This pilot trial of a complex intervention in obese pregnant women suggests greater potential for change in dietary intake than for change in physical activity, and through process evaluation illustrates the considerable advantage of performing an exploratory trial of a complex intervention in obese pregnant women before undertaking a large RCT.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

ISRCTN89971375.