Effect of a low-glycemic-index diet during pregnancy on obstetric outcomes

Medical Nutrition Therapy for Women with Gestational Diabetes: Current Practice and Future Perspectives

Gestational diabetes mellitus (GDM) is a complication that affects 20% of pregnancies worldwide. It is associated with adverse short- and long-term cardiometabolic outcomes for both mother and infant. Effective management of GDM involves lifestyle modifications, including medical nutrition therapy (MNT) and physical activity (PA), with the addition of insulin or metformin if glycaemic control remains inadequate. However, substantial gaps persist in the determination of optimal medical nutrition therapy (MNT) for women with GDM. Challenges in MNT include individual variation in glucose tolerance and changing maternal physiology and dietary requirements during pregnancy. Achieving optimal glycaemic control depends on careful macronutrient balance, particularly the distribution and quality of carbohydrate intake and sufficient protein and fat intake. Additionally, micronutrient deficiencies, such as inadequate vitamin D, calcium, and essential minerals, may exacerbate oxidative stress, inflammation, and glycaemic dysregulation, further impacting foetal growth and development. Cultural beliefs and dietary practices among pregnant women can also hinder adherence to recommended nutritional guidelines. Conditions like hyperemesis gravidarum (HG) affect ~1% to 2% of pregnant women can result in unintended energy and nutrient deficits. This special issue explores the current evidence and major barriers to optimising dietary therapy for women with GDM. It also identifies future research priorities to advance clinical practice, improve maternal and foetal outcomes, and address gaps in personalised nutrition interventions.

Higher prenatal dietary glycemic index in the third trimester of pregnancy is associated with infant negative affect at 6 months

The dietary glycemic index (GI) reflects post-prandial plasma glucose generation rate, with higher-GI foods rapidly increasing blood sugar. Prenatal consumption of high-GI foods is associated with offspring risk for obesity and metabolic disorders. The impact of prenatal dietary GI exposure on infant neurodevelopment remains unclear. Maternal dietary intake, percent adiposity, and insulin resistance were prospectively assessed during the second and third trimesters in a sample of women with healthy, singleton pregnancies (N = 302). Infant negative affect was prospectively assessed at six months using observer ratings (Still Face Paradigm) and caregiver-reports (Infant-Behavior Questionnaire-Revised). Structural equation models assessed the independent effects of second and third trimester maternal dietary GI, adiposity, insulin resistance on infant negative affect, adjusted for relevant covariates. Higher third, but not second, trimester dietary GI was associated with increased observer-rated infant negative affect (β = 0.14, p = .04) and with higher caregiver-reported infant sadness (β = 0.17, p = .01), suggesting a programming effect of prenatal dietary GI on infant neurodevelopment. Targeted interventions that decrease dietary GI in later pregnancy may prove more effective for optimizing infant behavioral health compared to longer-term changes needed to alter metabolic state. Identifying modifiable early contributors to infant negative affect supports proactive strategies for mitigating future psychopathology risk.

Maternal dietary patterns during pregnancy and birth weight: a prospective cohort study

BACKGROUND

Existing data on maternal dietary patterns and birth weight remains limited and inconsistent, especially in non-Western populations. We aimed to examine the relationship between maternal dietary patterns and birth weight among a cohort of Chinese.

METHODS

In this study, 4,184 mother-child pairs were included from the Iodine Status in Pregnancy and Offspring Health Cohort. Maternal diet during pregnancy was evaluated using a self-administered food frequency questionnaire with 69 food items. Principal component analysis was used to identify dietary patterns. Information on birth weight and gestational age was obtained through medical records. Adverse outcomes of birth weight were defined according to standard clinical cutoffs, including low birth weight, macrosomia, small for gestational age, and large for gestational age.

RESULTS

Three maternal dietary patterns were identified: plant-based, animal-based, and processed food and beverage dietary patterns, which explained 23.7% variance in the diet. In the multivariate-adjusted model, women with higher adherence to the plant-based dietary patten had a significantly higher risk of macrosomia (middle tertile vs. low tertile: odds ratio (OR) 1.45, 95% CI 1.00-2.10; high tertile vs. low tertile: OR 1.55, 95% CI 1.03-2.34; P-trend = 0.039). For individual food groups, potato intake showed positive association with macrosomia (high tertile vs. low tertile: OR 1.72, 95% CI 1.20-2.47; P-trend = 0.002). Excluding potatoes from the plant-based dietary pattern attenuated its association with macrosomia risk. No significant associations was observed for the animal-based or processed food and beverage dietary pattern with birth weight outcomes.

CONCLUSIONS

Adherence to a plant-based diet high in carbohydrate intake was associated with higher macrosomia risk among Chinese women. Future studies are required to replicate these findings and explore the potential mechanisms involved.

Preconception dietary glycemic index and risk for large-for-gestational age births

OBJECTIVES

Diets with a high glycemic index (GI) leading to elevated postprandial glucose levels and hyperinsulinemia during pregnancy have been inconsistently linked to an increased risk for large-for-gestational-age (LGA) births. The effects of prepregnancy dietary GI on LGA risk are, to our knowledge, unknown. We examined the association of prepregnancy dietary GI with LGA births and joint associations of GI and maternal overweight/obesity and infant sex with LGA births among 10 188 infants born without congenital anomalies from 1997 to 2011, using data from the National Birth Defects Prevention Study (NBDPS). The aim of this study was to investigate this association among infants without major congenital anomalies (controls) who participated in the NBDPS and to evaluate how prepregnancy BMI and infant sex may modify this association on the additive scale.

METHODS

Dietary intake was ascertained using a 58-item food frequency questionnaire. We dichotomized dietary GI into high and low categories using spline regression models. Infants with a birth weight at or above the 90th percentile for gestational age and sex, according to a U.S. population reference, were considered LGA. We used logistic regression to obtain odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Of the infants, 859 (9%) had a high dietary GI (cut-point: 59), and 1244 infants (12%) were born LGA. Unadjusted analysis suggested an inverse association between high dietary GI and LGA (OR, 0.79; 95% CI, 0.62-0.99). No association was observed in multivariable models when comparing high dietary GI intake between LGA births and all other births (OR, 0.94; 95% CI, 0.74-1.20) or when excluding small-for-gestational-age (SGA) births (OR, 0.94; 95% CI, 0.73-1.19). No joint associations with maternal overweight/obesity or infant sex were observed.

CONCLUSION

High prepregnancy maternal GI was not associated with LGA births independently of or jointly with other factors.

Protocol for the INFORMED (Individualised Patient Care and Treatment for Maternal Diabetes) Study: a randomised controlled trial embedded within routine care

INTRODUCTION

Diabetes in pregnancy presents a unique physiological challenge to manage glycaemia while maintaining adequate nourishment for the growing fetus. Women with diabetes who become pregnant are at greater risk of adverse maternal and newborn outcomes, compared with women without diabetes. Evidence suggests that control of (postprandial) glycaemia is key to manage maternal and offspring health but it is not yet clear (1) how diet and lifestyle moderate these shifts across the full duration of pregnancy or (2) what aspects of maternal and offspring health are associated with dysglycaemia.

METHODS AND ANALYSIS

To investigate these gaps, a cross-over randomised clinical trial has been embedded within routine clinical care. Seventy-six pregnant women in their first trimester with type 1 or type 2 diabetes (with or without medication) attending their routine antenatal appointments at National Health Service (NHS) Leeds Teaching Hospitals will be recruited. Following informed consent, data on women's health, glycaemia, pregnancy and delivery will be shared by the NHS with researchers. At each visit in the first (10-12 weeks), second (18-20 weeks) and third (28-34 weeks) trimester, participants will be asked for consent to: (1) lifestyle and diet questionnaires, (2) blood for research purposes and (3) analysis of urine collected at clinical visits. Additionally, participants will be asked to consume two blinded meals in duplicate in second and third trimester. Glycaemia will be assessed by continuous glucose monitoring as part of routine care. The primary outcome is the effect of experimental meals (high vs low protein) on postprandial glycaemia. Secondary outcomes include (1) the association between dysglycaemia and maternal and newborn health, and (2) the association between maternal metabolic profiles in early pregnancy with dysglycaemia in later pregnancy.

ETHICS AND DISSEMINATION

The Leeds East Research Ethics Committee and NHS (REC: 21/NE/0196) approved the study. Results will be published in peer-reviewed journals and disseminated to participants and the wider public.

TRIAL REGISTRATION NUMBER

ISRCTN57579163.

Nutritional and Exercise-Focused Lifestyle Interventions and Glycemic Control in Women with Diabetes in Pregnancy: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Diabetes disrupts one in six pregnancies, bestowing immediate and long-term health risks to mother and child. Diet and exercise are commonly prescribed to control dysglycemia, but their effectiveness across sub-populations and types of diabetes (type-1; type-2; or gestational diabetes mellitus, GDM) is uncertain. Therefore, a systematic review and meta-analysis on the effect of diet and/or exercise on glycemia in pregnant women with diabetes was conducted. Random effects models were used to evaluate effect sizes across studies and anticipated confounders (e.g., age, ethnicity, BMI). Of the 4845 records retrieved, 26 studies (8 nutritional supplements, 12 dietary, and 6 exercise interventions) were included. All studies were conducted in patients with GDM. Overall, supplement- and exercise-based interventions reduced fasting glucose (−0.30 mmol/L; 95% CI = −0.55, −0.06; p = 0.02; and 0.10 mmol/L; 95% CI = −0.20, −0.01; p = 0.04); and supplement- and diet-based interventions reduced HOMA-IR (−0.40; 95% CI = −0.58, −0.22; p < 0.001; and −1.15; 95% CI = −2.12, −0.17; p = 0.02). Subgroup analysis by confounders only confirmed marginal changed effect sizes. Our results suggest a favorable role of certain nutritional supplements, diet, and exercise practices on glycemia in women with GDM and underline a lack of evidence in ~20% of other diabetes-related pregnancies (i.e., women with pre-existing diabetes).

Maternal Dietary Glycemic Index and Glycemic Load in Pregnancy and Offspring Cord Blood DNA Methylation

OBJECTIVE

Suboptimal nutrition in pregnancy is associated with worse offspring cardiometabolic health. DNA methylation may be an underlying mechanism. We meta-analyzed epigenome-wide association studies (EWAS) of maternal dietary glycemic index and load with cord blood DNA methylation.

RESEARCH DESIGN AND METHODS

We calculated maternal glycemic index and load from food frequency questionnaires and ran EWAS on cord blood DNA methylation in 2,003 mother-offspring pairs from three cohorts. Analyses were additionally stratified by maternal BMI categories. We looked-up the findings in EWAS of maternal glycemic traits and BMI as well as in EWAS of birth weight and child BMI. We examined associations with gene expression in child blood in the online Human Early Life Exposome eQTM catalog and in 223 adipose tissue samples.

RESULTS

Maternal glycemic index and load were associated with cord blood DNA methylation at 41 cytosine-phosphate-guanine sites (CpGs, P < 1.17 × 10-7), mostly in mothers with overweight/obesity. We did not observe overlap with CpGs associated with maternal glycemic traits, BMI, or child birth weight or BMI. Only DNA methylation at cg24458009 and cg23347399 was associated with expression of PCED1B and PCDHG, respectively, in child blood, and DNA methylation at cg27193519 was associated with expression of TFAP4, ZNF500, PPL, and ANKS3 in child subcutaneous adipose tissue.

CONCLUSIONS

We observed multiple associations of maternal glycemic index and load during pregnancy with cord blood DNA methylation, mostly in mothers with overweight/obesity; some of these CpGs were associated with gene expression. Additional studies are required to further explore functionality, uncover causality, and study pathways to offspring health.

Food taboos during pregnancy: meta-analysis on cross cultural differences suggests specific, diet-related pressures on childbirth among agriculturalists

Pregnancy is the most delicate stage of human life history as well as a common target of food taboos across cultures. Despite puzzling evidence that many pregnant women across the world reduce their intake of nutritious foods to accomplish cultural norms, no study has provided statistical analysis of cross-cultural variation in food taboos during pregnancy. Moreover, antenatal practices among forager and agriculturalists have never been compared, despite subsistence mode being known to affect staple foods and lifestyle directly. This gap hinders to us from understanding the overall threats attributed to pregnancy, and their perceived nutritional causes around the world. The present study constitutes the first cross-cultural meta-analysis on food taboos during pregnancy. We examined thirty-two articles on dietary antenatal restrictions among agricultural and non-agricultural societies, in order to: (i) identify cross-culturally targeted animal, plant and miscellaneous foods; (ii) define major clusters of taboo focus; (iii) test the hypothesis that food types and clusters of focus distribute differently between agricultural and non-agricultural taboos; and (iv) test the hypothesis that food types distribute differently across the clusters of taboo focus. All data were analysed in SPSS and RStudio using chi-squared tests and Fisher's exact tests. We detected a gradient in taboo focus that ranged from no direct physiological interest to the fear of varied physiological complications to a very specific concern over increased birth weight and difficult delivery. Non-agricultural taboos were more likely to target non-domesticated animal foods and to be justified by concerns not directly linked to the physiological sphere, whereas agricultural taboos tended to targed more cultivated and processed products and showed a stronger association with concerns over increased birth weight. Despite some methodological discrepancies in the existing literature on food taboos during pregnancy, our results illustrate that such cultural traits are useful for detecting perception of biological pressures on reproduction across cultures. Indeed, the widespread concern over birth weight and carbohydrate rich foods overlaps with clinical evidence that obstructed labor is a major threat to maternal life in Africa, Asia and Eurasia. Furthermore, asymmetry in the frequency of such concern across subsistence modes aligns with the evolutionary perspective that agriculture may have exacerbated delivery complications. This study highlights the need for the improved understanding of dietary behaviors during pregnancy across the world, addressing the role of obstructed labor as a key point of convergence between clinical, evolutionary and cultural issues in human behavior.

A high-protein low-glycemic index diet attenuates gestational weight gain in pregnant women with obesity: the "An optimized programming of healthy children" (APPROACH) randomized controlled trial

BACKGROUND

Prepregnancy overweight and excessive gestational weight gain (GWG) increase the risk of complications and offspring obesity.

OBJECTIVES

We aimed to investigate the effect of a high-protein low-glycemic index (HPLGI) diet on GWG, birth weight, and risk of gestational complications in pregnant women with obesity.

METHODS

A total of 279 women with prepregnancy overweight or obesity (BMI: 28-45 kg/m2), between 18 and 45 y old, and in their late first trimester with singleton pregnancies, were randomly assigned to 1 of 2 ad libitum diets: a high-protein low-glycemic index diet (HPLGI: 25%-28% of energy from protein and glycemic index ≤ 55) and a moderate-protein moderate-glycemic index diet (MPMGI: 15%-18% of energy from protein and glycemic index ∼60). Diets were consumed from gestational week 15 and throughout pregnancy. Participants received dietary guidance by a clinical dietician 9 times to facilitate adherence.

RESULTS

Out of 141 and 138 women randomly assigned to the HPLGI and MPMGI diets, 105 and 104 completed the intervention, respectively (75%). In the available case analyses, GWG was 6.8 ± 1.3 kg among women assigned the HPLGI diet and this was significantly lower, by -1.7 kg (95% CI: -2.8, -0.5 kg; P = 0.004), than the GWG of 8.5 ± 1.3 kg among women assigned the MPMGI diet. There were no significant differences between diets on major neonatal outcomes (birth weight and other anthropometric measures). The incidence of composite pregnancy complications was lower for the HPLGI than for the MPMGI diet (35.4% compared with 53.7%, respectively; P = 0.009), including cesarean delivery (15.4% compared with 28.8%, respectively; P = 0.03). There were no reported maternal, fetal, or neonatal deaths. Incidence of miscarriages (1%-2%) did not differ between groups.

CONCLUSIONS

A moderate increase in dietary protein in conjunction with a reduction in glycemic index during the last 2 trimesters of pregnancy reduced GWG and limited complications and cesarean deliveries among women with overweight or obesity.

The association of a low glycaemic index diet in pregnancy with child body composition at 5 years of age: A secondary analysis of the ROLO study

INTRODUCTION

Childhood obesity remains a significant global health concern. Early intervention through maternal diet during pregnancy represents a possible mode of improving childhood adiposity.

AIM

To examine the impact of a low glycaemic index diet during pregnancy on offspring anthropometry at 5 years of age.

METHODS

This is a secondary analysis of 387 children from the ROLO pregnancy study 5 years' post-intervention. At the follow-up, BMI, circumferences and skinfold thickness were obtained. A subgroup of 103 children had a DXA scan completed. Statistical analyses included Independent sample t tests, Mann Whitney-U tests and chi-square tests to compare the intervention and control groups. Adjusted analysis using linear regression controlled for significant confounders between participants who returned at follow-up and those that did not.

RESULTS

There were no significant differences in BMI (16.05 kg/m² vs 16.16 kg/m² , P = 0.403), general adiposity (36.60 mm vs 36.00 mm, P = 0.920), central adiposity (0.61 mm vs 0.60 mm, P = 0.540), total fat mass (4.91 kg vs 4.71 kg, P = 0.377) or total lean mass (14.29 kg vs 14.56 kg, P = 0.386) between the intervention and control groups, respectively. No associations were observed in 5-year outcomes in adjusted analyses when controlling for maternal age at delivery, maternal early pregnancy BMI, maternal education and gestational age.

CONCLUSION

Our study found no evidence that a low glycaemic index diet in pregnancy impacts offspring anthropometry 5 years' post-intervention. Therefore, modulating maternal carbohydrate quality in pregnancy may not be an appropriate approach to improving weight status in childhood. Future research should investigate the impact of other dietary practices in pregnancy on child health.

Acceptability of the Pregnancy, Exercise, and Nutrition Research Study With Smartphone App Support (PEARS) and the Use of Mobile Health in a Mixed Lifestyle Intervention by Pregnant Obese and Overweight Women: Secondary Analysis of a Randomized Controlled Trial

Background

Dietary interventions can improve pregnancy outcomes among women with increased BMI. Although the interest in mobile health interventions is growing, little is known about the acceptability of smartphone apps to support lifestyle interventions in such a cohort.

Objective

We aimed to assess the acceptability of the pregnancy, exercise, and nutrition research study with smartphone app support (PEARS) and the use of mobile health in a mixed lifestyle intervention delivered to overweight and obese pregnant women.

Methods

PEARS was a randomized controlled trial of a low glycemic index dietary intervention with exercise prescription and a smartphone app, which was delivered to pregnant women who were overweight or obese. Acceptability questionnaires were completed by the intervention group at 28 weeks of gestation (n=149) and at postintervention (n=123). Maternal characteristics were recorded (ie, age, ethnicity, BMI, socioeconomic status). Associations between maternal characteristics and acceptability of the intervention and app were analyzed using two-tailed t tests, Mann-Whitney U tests, chi-square test, and logistic regression. One-on-one semistructured interviews were conducted with a subcohort of the intervention participants (n=28) at 34 weeks of gestation, in which the participants shared their experiences of the PEARS intervention.

Results

The intervention was generally accepted, with respondents agreeing that the diet was easy to follow (98/148, 68.5%), enjoyable (106/148, 74.1%), and affordable (110/148, 76.9%). Qualitative and quantitative results were consistent with each another, both demonstrating that app acceptability was high. The participants agreed that the app was enjoyable (96/120, 80.0%) and easy to use (116/119, 97.5%). Compared to those with tertiary education, those with lower education levels were more likely to enjoy the dietary changes (P=.04). Enjoyment of the app was associated with disadvantaged neighborhood deprivation index (P=.01) and higher BMI (P=.03).

Conclusions

The PEARS intervention and use of a supportive smartphone app were accepted by pregnant women, particularly by those from vulnerable subgroups of this population.

Trial Registration

International Standard Randomized Controlled Trial Number (ISRCTN) 29316280; https://www.isrctn.com/ISRCTN29316280

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.

The impact of maternal stress on offspring birth weight and the mediating effect of dietary patterns: the Shanghai Maternal-Child Pairs Cohort study

BACKGROUND

Maternal stress and nutrition during pregnancy are two of the most commonly studied factors in the context of fetal development. However, few investigators have considered the combined effects of stress and diet in pregnant women and their offspring.

AIMS

To determine the impact of maternal stress on offspring birth weight, and the potential mediating role of maternal dietary patterns.

METHODS

A total of 3542 pregnant women and their singleton live births were recruited from Shanghai Maternal-Child Pairs Cohort (Shanghai MCPC). Maternal stress was assessed using the Life Event Scale for Pregnant Women (LESPW) in early and late pregnancy. Food frequency questionnaire (FFQ) was performed to evaluate maternal diet in late pregnancy. Multiple linear regression was conducted to estimate the associations between maternal stress and child birth weight. Logistic regression was performed to calculate the association between maternal stress and small for gestational age (SGA)/large for gestational age (LGA). The bootstrap method was used to investigate the mediating effects of maternal dietary patterns.

RESULTS

Maternal subjective events stress (β = 0.367) and total stress (β = 0.079) in early pregnancy, and positive objective life events stress (β = 0.275) in late pregnancy, were positively associated with birth weight. Maternal dietary pattern of "high-fat and sugar" mediated the associations between subjective events stress and total stress during early pregnancy and birth weight. An increased risk for LGA was observed among women exposed to relatively higher stress during early pregnancy (OR, 1.416; 95% CI, 1.035-1.937). No statistically significant associations were found between maternal stress during late pregnancy and child birth weight or SGA/LGA.

CONCLUSIONS

Maternal life events stress during early pregnancy significantly increases neonatal birth weight and risk for LGA, which may mediate by a "high-fat and sugar" dietary pattern.

LIMITATIONS

The lack of biological markers limits the explanation of the mechanism. The assessment of diet used food intake frequency to evaluate dietary characteristics, which may miss information of energy intake.

Effects of the Dietary Approaches to Stop Hypertension (DASH) on Pregnancy/Neonatal Outcomes and Maternal Glycemic Control: A Systematic Review and Meta-analysis of Randomized Clinical Trials

BACKGROUND & OBJECTIVE

No systematic review to date has appraised the impact of the Dietary Approaches to Stop Hypertension (DASH) eating plan on maternal glycemic control and pregnancy outcomes. Thus, we conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) to ascertain whether the DASH diet in pregnant women ameliorates their glycemic control and neonatal outcomes when compared to standard diets.

METHODS

We performed a comprehensive systematic review and meta-analysis of RCTs on PubMed/MEDLINE, Web of Science, SCOPUS, and Embase from the inception until October 2019.

RESULTS

Six studies met the eligibility criteria and were included in the quantitative meta-analysis. The pregnant women had cardiometabolic disorders such as gestational diabetes, obesity, and hypertension. The meta-analysis suggested a significant effect of DASH diet on fasting plasma levels of glucose (WMD = -6.239 mg/dl; 95% CI: -11.915, -0.563, p = 0.031), but not for the homeostasis model assessment of insulin resistance (WMD = -1.038; 95% CI: -2.704, 0.627, p = 0.22). Following the DASH diet during pregnancy decreased the risk of gestational preeclampsia (RR = 0.667; 95% CI: 0.451, 0.987, p = 0.043), macrosomia (birth weight >4000 g) (RR = 0.294; 95% CI: 0.120, 0.721, p = 0.043), and large for gestational age (RR = 0.452; 95% CI: 0.211, 0.969, p = 0.041). Consuming DASH diet during pregnancy neither increased nor decreased the risk of cesarean section, polyhydramnios, preterm birth (<37 weeks), and small for gestational age. The mean newborn head circumference (cm) (WMD = -0.807; 95% CI: -1.283, -0.331, p = 0.001) and ponderal index (kg/m³) (RR = -0.396; 95% CI: -0.441, -0.350, p = 0.000) in the group receiving the DASH diet were lower than in the control group.

CONCLUSION

The adherence of pregnant women with cardiometabolic disorders to DASH eating pattern has a significant effect on decreasing fasting plasma glucose levels, ponderal index, incidence of preeclampsia, fetal macrosomia, large for gestational age, and newborn head circumference.

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.

The Impact of an Early Lifestyle Intervention on Pregnancy Outcomes in a Cohort of Insulin-Resistant Overweight and Obese Women

Obese women are more likely to have decreased insulin sensitivity and are at increased risk for many adverse pregnancy outcomes. An early lifestyle intervention (LI) may have the potential to reduce the impact of insulin resistance (IR) on perinatal outcomes. We report post hoc analysis of an open-label randomized control trial that includes IR women with body-mass index ≥25 randomly assigned to a LI with a customized low glycemic index diet or to standard care (SC) involving generic counseling about healthy diet and physical activity. Women were evaluated at 16, 20, 28, and 36 weeks of gestation, at which times perinatal outcomes were collected and analyzed. An oral-glucose-tolerance test (OGTT) showed that women in the LI group had lower plasma glucose levels at 120 min at 16-18 weeks of gestation, and at 60 and 120 min at 24-28 weeks. More importantly, these women had a lower rate of large-for-gestational-age (LGA) infants (p = 0.04). Interestingly, the caloric restriction and low-glycemic index diet did not increase the rate of small-for-gestational-age (SGA) babies in the LI group. A lifestyle intervention started early in pregnancy on overweight and obese women had the potential to restore adequate glucose tolerance and mitigate the detrimental role of IR on neonatal outcomes, especially on fetal growth.

Development of Obesity: The Driver and the Passenger

Obesity has reached epidemic proportions and is one of the greatest challenges for public health in the twenty-first century. The macronutrient composition of diets, in particular the amount and ratio of carbohydrates, fat and protein, have received considerable attention in recent decades due to its potential relevance to the development of obesity and weight loss. The effects of various macronutrients on body weight regulation are still under debate. High-carbohydrate diets, and particularly high-fat diets, have been blamed for the increase in the prevalence of obesity. This paper shows that neither fat nor carbohydrates are fattening per se. Mixed diets with substantial amounts of fat and high-glycemic carbohydrates, like current WDs, are required to promote weight gain and obesity. High-glycemic carbohydrates are the active partner (the "driver"), which promotes fat storage through its insulinogenic effect, while fat is the passive partner (the "passenger") on the way to obesity. Elevated insulin levels (postprandial, but more importantly due to hypersecretion and hyperinsulinemia) promote fat storage and play a key role in obesogenesis and the obesity epidemic. Furthermore, mixed diets high in high-glycemic carbohydrates and fat promote fetal programming, with long-term adverse impacts on the offspring, including insulin hypersecretion, (childhood) obesity and metabolic diseases. Maternal obesity and high weight gain during pregnancy have also been linked to deleterious effects on fetal programming. As the global obesity epidemic increasingly affects women of reproductive age, a significant percentage of fetuses will experience fetal programming with a tendency towards obesity - a self-reinforcing process that further fuels the epidemic. A change in lifestyle and diet composition is needed to prevent or limit the development of obesity and related diseases.

Effects of maternal diets on preterm birth and low birth weight: a systematic review

Current evidence indicates that maternal diets before and during pregnancy could influence rates of preterm birth, low birth weight (LBW) and small for gestational age (SGA) births. However, findings have been inconsistent. This review summarised evidence concerning the effects of maternal diets before and during pregnancy on preterm birth, LBW and SGA. Systematic electronic database searches were carried out using PubMed, Embase, Scopus and Cochrane library using the preferred reporting items for systematic reviews and meta-analyses guidelines. The review included forty eligible articles, comprising mostly of prospective cohort studies, with five randomised controlled trials. The dietary patterns during pregnancy associated with a lower risk of preterm birth were commonly characterised by high consumption of vegetables, fruits, whole grains, fish and dairy products. Those associated with a lower risk of SGA also had similar characteristics, including high consumption of vegetables, fruits, legumes, seafood/fish and milk products. Results from a limited number of studies suggested there was a beneficial effect on the risk of preterm birth of pre-pregnancy diet quality characterised by a high intake of fruits and proteins and less intake of added sugars, saturated fats and fast foods. The evidence was mixed for the relationship between maternal dietary patterns during pregnancy and LBW. These findings indicate that better maternal diet quality during pregnancy, characterised by a high intake of vegetables, fruits, whole grains, dairy products and protein diets, may have a synergistic effect on reducing the risk of preterm birth and SGA.

Could consanguineous marriage provide a cultural alleviation for the obstetric dilemma?

In placental mammals, a poor fit between the physical dimensions of the fetus and maternal pelvis increases the likelihood of obstructed labour. This problem is especially relevant to humans, as our species demonstrates both unique adaptations in pelvic shape and structure associated with bipedalism, and fetal encephalization. Natural selection is expected to have favoured adaptations that reduce the chances of such mismatch within individual mother-offspring dyads. Here, I hypothesise that the cultural practice of consanguineous marriage may have been favoured, on account of increasing the genetic similarity between mothers and offspring and hence the correlation between maternal and fetal physical dimensions. These benefits could be amplified if consanguineous marriage was accompanied by assortative mating for height. An additional benefit of consanguineous marriage for childbirth is the slight reduction in birth size of such offspring compared to non-consanguineous unions. Although the offspring of consanguineous unions have elevated risks of morbidity and mortality, these risks are moderate and the practice could still have been favoured by selection if the reduction in maternal mortality was greater than the increased mortality among individual offspring. This hypothesis could be tested directly by investigating whether rates of obstructed labour are lower in individuals and populations practising consanguineous marriage. At a broader level, phylogenetic analysis could be conducted to test whether consanguineous marriage appears to have originated in the areas where intensive agriculture was first practiced, as adult height typically fell in such populations, potentially exacerbating the risk of obstructed labour.

Evidenced-Based Nutrition for Gestational Diabetes Mellitus

PURPOSE OF REVIEW

To review the latest evidence for dietary interventions for treatment of gestational diabetes (GDM).

RECENT FINDINGS

High-quality systematic reviews demonstrate no major advantages between the low-carbohydrate or calorie-restricted diets. However, the low glycemic index (GI) diet, characterized by intake of high-quality, complex carbohydrates, demonstrated lower insulin use and reduced risk of macrosomia in multiple reviews. Recent evidence suggests the Mediterranean diet is safe in pregnancy, though trials are needed to determine its efficacy over conventional dietary advice. Currently, there are insufficient data to support the safety of the ketogenic diet for the treatment of GDM. The low GI diet may improve maternal and neonatal outcomes in GDM. The liberalized carbohydrate intake is less restrictive, culturally adaptable, and may improve long-term maternal adherence. Further research is needed to establish the optimal, most sustainable, and most acceptable medical nutrition therapy for management of women with GDM.

From conception to infancy - early risk factors for childhood obesity

Maternal lifestyle during pregnancy, as well as early nutrition and the environment infants are raised in, are considered relevant factors for the prevention of childhood obesity. Several models are available for the prediction of childhood overweight and obesity, yet most have not been externally validated. Moreover, the factors considered in the models differ among studies as the outcomes manifest after birth and depend on maturation processes that vary between individuals. The current Review examines and interprets data on the early determinants of childhood obesity to provide relevant strategies for daily clinical work. We evaluate a selection of prenatal and postnatal factors associated with child adiposity. Actions to be considered for preventing childhood obesity include the promotion of healthy maternal nutrition and weight status at reproductive age and during pregnancy, as well as careful monitoring of infant growth to detect early excessive weight gain. Paediatricians and other health-care professionals should provide scientifically validated, individual nutritional advice to families to counteract excessive adiposity in children. Based on systematic reviews, original papers and scientific reports, we provide information to help with setting up public health strategies to prevent overweight and obesity in childhood.

Effectiveness of Following Mediterranean Diet Recommendations in the Real World in the Incidence of Gestational Diabetes Mellitus (GDM) and Adverse Maternal-Foetal Outcomes: A Prospective, Universal, Interventional Study with a Single Group. The St Carlos Study

We reported that a Mediterranean Diet (MedDiet), supplemented with extra-virgin olive oil (EVOO) and pistachios, reduces GDM incidence and several other adverse outcomes. In order to assess its translational effects in the real world we evaluated the effect of MedDiet from 1st gestational visit in GDM rate compared with control (CG) and intervention (IG) groups from the previously referred trial. As secondary objective we also compared adverse perinatal outcomes between normoglycemic and diabetic women. This trial is a prospective, clinic-based, interventional study with a single group. 1066 eligible normoglycaemic women before 12 gestational weeks were assessed. 932 women (32.4 ± 5.2 years old, pre-gestational BMI 22.5 ± 3.5 kg/m2) received a motivational lifestyle interview with emphasis on daily consumption of EVOO and nuts, were followed-up and analysed. Binary regression analyses were used to examine the risk for each pregnancy outcome, pregnancy-induced hypertension, preeclampsia, gestational weight gain (GWG), caesarean-section, perineal trauma, preterm delivery, small (SGA) and large for gestational age (LGA), and Neonatal Intensive Care Unit admissions. GDM was diagnosed in 13.9%. This rate was significantly lower than the CG: RR 0.81 (0.73-0.93), p < 0.001 and no different from the IG: RR 0.96 (0.85-1.07), p = 0.468. GWG was lower in diabetic women (10.88 ± 6.46 vs. 12.30 ± 5.42 Kg; p = 0.013). Excessive weight gain (EWG) was also lower in GDM [RR 0.91 (0.86-0.96); p < 0.001] without a significant increase of insufficient weight gain. LGA were also lower (1 (0.8%) vs. 31 (3.9%); p < 0.05)), and SGA were similar (5 (3.8%) vs. 30 (3.7%)). LGA were associated to EWG (RR 1.61 (1.35-1.91), p < 0.001). Differences in other maternal-foetal outcomes were not found. In conclusions an early MedDiet nutritional intervention reduces GDM incidence and maternal-foetal adverse outcomes and should be universally applied as 1st line therapy. GDM might not be consider as a high risk pregnancy any longer.

Maternal dietary glycaemic change during gestation influences insulin-related gene methylation in the placental tissue: a genome-wide methylation analysis

Background

Studies have shown that the effects of maternal nutrition exposure during gestation influence metabolic risk in early life through an epigenetic mechanism. Low glycaemic index (GI) diets benefit both maternal and neonatal gestational outcomes. We hypothesize that maternal dietary GI or glycaemic load (GL) changes during pregnancy impact placental DNA methylation, especially in insulin resistance-related genes.

Methods

From a clinical trial of overweight pregnant women, 12 subjects who successfully reduced their GI and another 12 whose GI increased despite the intervention were selected. A genome-wide differential methylation analysis of placental tissue DNA was conducted, followed by bioinformatic annotation and validation analysis. The distribution of genome-wide differentially methylated regions (DMRs) and CpG sites was described. Six CpG sites in regulatory regions of four insulin-related genes (PLIN1, CPT1B, SSTR4, and CIDEA) were selectively validated by pyrosequencing. Pairwise Spearman correlation analysis was performed to test methylation–phenotype association in an additional 153 subjects from the same trial. Correlation between methylation of significant sites and placental mRNA expression of SSTR4 was also analysed.

Results

Dietary GI decreased by 24.3 (26.2–20.1) in the group who responded appropriately to the intervention and increased by 19.6 (15.2–29.1) in the comparison group. Epigenome-wide analysis identified 108 DMRs and 365 CpG sites with P < 0.05 adjusted by false discovery rate, distributed over all chromosomes. The methylation level of cg05009389 in the 3′ UTR of PLIN1 was negatively correlated with maternal weight gain (ρ = − 0.21, P = 0.027) and increase in insulin levels (ρ = − 0.24, P = 0.015) during gestation. Methylation levels of cg17586860 and cg18197392 in the 5′ UTR region of SSTR4 were negatively correlated with changes in dietary carbohydrate intake (ρ = − 0.24, Ps ≤ 0.006) and GL across gestation (ρ = − 0.23, Ps ≤ .008). This correlation survived the adjustment for maternal factors such as dietary GI, body mass index, and gestational diabetes. Up to 89% of cg18197392 methylation was explained by GL change. Cg14631053 methylation correlated positively with mRNA expression of SSTR4 in the placenta (ρ = 0.20, P = 0.037).

Conclusions

We provide the first evidence that maternal dietary GI changes during gestation may impact placental DNA methylation of insulin regulation genes. This supports the hypothesis that placental methylation may be the epigenetic mechanism through which maternal diet influences the metabolic health of offspring.

Electronic supplementary material

The online version of this article (10.1186/s12263-019-0634-x) contains supplementary material, which is available to authorized users.

Effectiveness of Low Glycemic Index Diet Consultations Through a Diet Glycemic Assessment App Tool on Maternal and Neonatal Insulin Resistance: A Randomized Controlled Trial

Background

Low glycemic index (LGI) diet has shown to be effective in reducing maternal and neonatal complications in high-risk pregnancies.

Objective

This trial aimed to examine the effectiveness of individualized LGI diet consultations based on the accurate diet glycemic load (GL) assessment tool on maternal and neonatal insulin resistance levels and diet behavior changes in overweight and obese pregnant women.

Methods

Overweight and obese pregnant women were recruited before 16 weeks of gestation and randomized to the LGI diet arm or the control arm. All participants received standard dietary education according to the Chinese Dietary Guide for Pregnant Women. In the intervention arm, additional individualized dietary GL assessments were performed using an app and instructions of lowering diet glycemic index (GI) to achieve LGI diet were provided by a clinical dietitian at early, middle, and late gestation. Primary outcomes were serum insulin at late gestation, incidence of gestational diabetes mellitus (GDM) for mothers, and cord blood C-peptide level of neonates.

Results

In total, 400 subjects were randomized and received different interventions. There were no significant differences in maternal serum insulin levels (13.2 [9.3−13.2] uU/mL vs 12.4 [10.5−12.4] uU/mL), incidence of GDM (45 [22.5%] vs 43 [21.5%]), or cord blood C-peptide levels (mean 0.9ng/mL [SD 0.7] vs mean 0.8ng/mL [SD 0.6]) in the intervention group compared with the controls. The diet GI at late gestation was similar (mean 63.2 [SD 10.4] vs mean 64.3 [SD 10.4]), whereas greater diet fiber intake was observed in the intervention group (mean 11.6 grams [SD 8.0] vs mean 9.0 grams [SD 5.6]; P=.006). Adherence measurements did not significantly differ between 2 groups.

Conclusions

Individualized LGI diet consultations for overweight and obese pregnant women failed to make a significant difference in maternal or neonatal insulin resistance compared with the standard gestational diet consultation.

Trial Registration

ClinicalTrials.gov NCT01628835; http://clinicaltrials.gov/ct2/show/NCT01628835 (Archived by WebCite at http://www.webcitation.org/77LHgWP0k)

Association of food groups intake and physical activity with gestational diabetes mellitus in Iranian women

Background: It is suggested that combining a healthy diet with physical activity during and before pregnancy have a significant effect on insulin sensitivity. This study aimed to investigate the relationship between physical activity and diet before and during pregnancy with the risk of gestational diabetes mellitus (GDM).Methods: A case-control study was conducted on 173 women with GDM diagnosed during the pregnancy as the case group and 168 women with a negative test for GDM as controls. Weight and height were measured and BMI was calculated. Dietary intake and physical activity data during pregnancy were collected using 24-hour food recall questionnaire and international physical activity questionnaire (IPAQ).Results: Body mass index and the intake of refined sugars, high fat dairy products, and fried foods were significantly higher and the intake of fruit and animal oil intake were significantly lower in the case group compared to the control group (All p < .05). However, there was not any significant association between the level of physical activity, vegetable intake, and total energy intake with the risk of GDM.Conclusions: According to the results of this study, dietary intake before and during the pregnancy have a critical effect on the risk of GDM. Appropriate dietary planning for pregnant women can reduce the risk of GDM.

Association between Dietary Glycemic Index and Excess Weight in Pregnant Women in the First Trimester of Pregnancy

OBJECTIVE

To assess the association between dietary glycemic index (GI) and excess weight in pregnant women in the first trimester of pregnancy.

METHODS

A cross-sectional study in a sample of 217 pregnant women was conducted at the maternal-fetal outpatient clinic of the Hospital Geral de Fortaleza, Fortaleza, state of Ceará, Brazil, for routine ultrasound examinations in the period between 11 and 13 weeks + 6 days of gestation. Weight and height were measured and the gestational body mass index (BMI) was calculated. The women were questioned about their usual body weight prior to the gestation, considering the prepregnancy weight. The dietary GI and the glycemic load (GL) of their diets were calculated and split into tertiles. Analysis of variance (ANOVA) or Kruskal-Walls and chi-squared (χ2) statistical tests were employed. A crude logistic regression model and a model adjusted for confounding variables known to influence biological outcomes were constructed. A p-value < 0.05 was considered significant for all tests employed.

RESULTS

The sample group presented a high percentage of prepregnancy and gestational overweight (39.7% and 40.1%, respectively). In the tertile with the higher GI value, there was a lower dietary intake of total fibers (p = 0.005) and of soluble fibers (p = 0.008). In the third tertile, the dietary GI was associated with overweight in pregnant women in the first trimester of gestation, both in the crude model and in the model adjusted for age, total energy intake, and saturated fatty acids. However, this association was not observed in relation to the GL.

CONCLUSION

A high dietary GI was associated with excess weight in women in the first trimester of pregnancy.

Improving the effectiveness of lifestyle interventions for gestational diabetes prevention: a meta-analysis and meta-regression

BACKGROUND

Diet and exercise during pregnancy have been used to prevent gestational diabetes mellitus (GDM) with some success.

OBJECTIVE

To examine the effectiveness of lifestyle intervention on GDM prevention and to identify key effectiveness moderators to improve the prevention strategy.

SEARCH STRATEGY

Pubmed, Scopus, Cochrane, and cross-references were searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating lifestyle interventions during pregnancy for GDM prevention.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data. A random-effects model was used to analyse the relative risk (RR) and 95% confidence interval (95% CI). Meta-regressions and subgroup analyses were used to investigate important moderators of effectiveness.

MAIN RESULTS

Forty-seven RCTs involving 15 745 participants showed that diet and exercise during pregnancy were preventive of GDM (RR 0.77, 95% CI 0.69-0.87). Four key aspects were identified to improve the preventive effect: targeting the high-risk population; an early initiation of the intervention; the correct intensity and frequency of exercise; and gestational weight gain management. Although 24 RCTs targeted women who were overweight or obese, body mass index (BMI) failed to predict the effectiveness of an intervention. Instead, interventions are most effective in high-incidence populations rather than simply in women who are overweight or obese. Furthermore, exercise of moderate intensity for 50-60 minutes twice a week could lead to an approximately 24% reduction in GDM.

CONCLUSION

The best strategy to prevent GDM is to target the high-risk population predicted by risk evaluation models and to control the gestational weight gain of women through intensified diet and exercise modifications early in their pregnancy.

TWEETABLE ABSTRACT

Four key effectiveness moderators of lifestyle interventions for GDM prevention.

A Slow-Digesting, Low-Glycemic Load Nutritional Beverage Improves Glucose Tolerance in Obese Pregnant Women Without Gestational Diabetes

BACKGROUND

Obesity is a risk factor for gestational diabetes (gestational diabetes). Low-glycemic index diets attenuate hyperglycemia. We designed a study to determine whether a slow-digesting, low-glycemic load (SD-LGL) beverage improves glucose tolerance in obese pregnant women without GDM.

METHODS

This was a 3-arm comparison study comparing the effects of an SD-LGL nutritional beverage (glycemic load [GL] 730), an isocaloric control beverage (GL 1124), and habitual diet on glycemia in obese pregnant women. Sixteen women (mean body mass index 37 kg/m²) were recruited at 24-28 weeks to receive either the SD-LGL or eucaloric control beverage. This was consumed with breakfast and as a midafternoon snack over 2 days with a controlled diet. Following a 2-day washout period of habitual diet, women completed 2 days on the alternative beverage with controlled diet. A 10-h fast preceded each intervention phase. Twenty-four hour glucose was measured using continuous glucose monitoring.

RESULTS

Consumption of the lower GL beverage was associated with improved measures of glycemia, compared with the control beverage and habitual diet at different time periods. Glucose estimates for control versus SD-LDL at 24 h (0.23 mmol/L [0.16 to 0.31], P < 0.001), daytime (0.26 mmol/L [0.18 to 0.34], P < 0.001), and nighttime (0.05 mmol/L [-0.01 to 0.11], P = 0.09). Postprandial glucose was lower after breakfast but not after dinner, compared with the control beverage (0.09 mmol/L [0.01 to 0.18], P = 0.03).

CONCLUSION

A slow-digesting, low-glycemic nutritional beverage may facilitate improved glucose control in obese pregnant women. To address potential benefit for clinical outcomes, a randomized controlled trial is warranted.

Glycaemic Index of Maternal Dietary Carbohydrate Differentially Alters Fto and Lep Expression in Offspring in C57BL/6 Mice

Maternal diet and gestational hyperglycaemia have implications for offspring health. Leptin (LEP) and fat mass and obesity-associated (FTO) alleles are known to influence body fat mass in humans, potentially via effects on appetite. We hypothesized that expression of Fto, Lep, and other appetite-related genes (Argp, Npy, Pomc, Cart, Lepr) in the offspring of female mice are influenced by the glycaemic index (GI) of carbohydrates in the maternal diet. C57BL/6 mice were randomly assigned to low or high GI diets and mated with chow-fed males at eight weeks of age. Male pups were weaned at four weeks and randomly divided into two groups, one group following their mother's diet (LL and HH), and one following the standard chow diet (LC and HC) to 20 weeks. Fto expression was 3.8-fold higher in the placenta of mothers fed the high GI diet (p = 0.0001) and 2.5-fold higher in the hypothalamus of 20-week old offspring fed the high GI (HH vs. LL, p < 0.0001). By contrast, leptin gene (Lep) expression in visceral adipose tissue was 4.4-fold higher in four-week old offspring of low GI mothers (LC vs. HC, p < 0.0001) and 3.3-fold higher in visceral adipose tissue of 20-week old animals (LL vs. HH, p < 0.0001). Plasma ghrelin and leptin levels, and hypothalamic appetite genes were also differentially regulated by maternal and offspring diet. These findings provide the first evidence in an animal model that maternal high GI dietary carbohydrates that are digested and absorbed faster may contribute to programming of appetite in offspring.

Gestational diabetes mellitus: Multi-disciplinary treatment approaches

Gestational diabetes mellitus (GDM) is the most common metabolic disease of pregnancy, associated with several perinatal complications. Adequate glycemic control has been proved to decrease risk of GDM-related complications. Several studies have shown the beneficial effect of exercise and medical nutrition treatment on glycemic and weight control in GDM-affected women. Moreover, pharmacological agents, such as insulin and specific oral anti-diabetic agents can be prescribed safely during pregnancy, decreasing maternal blood glucose and, thus, perinatal adverse outcomes. Multi-disciplinary treatment approaches that include both lifestyle modifications (medical nutritional therapy and daily physical exercise) and pharmacological treatment, in cases of failure of the former, constitute the most effective approach. Insulin is the gold standard pharmacological agent for GDM treatment. Metformin and glyburide are two oral anti-diabetic agents that could serve as alternative, although not equal in terms of effectiveness and safety, treatment for GDM. As studies on short-term safety of metformin are reassuring, in some countries it is considered as first-line treatment for GDM management. More studies are needed to investigate the long-term effects on offspring. As safety issues have been raised on the use of glyburide during pregnancy, it must be used only when benefits surpass possible risks.

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.

Modern dietary guidelines for healthy pregnancy; maximising maternal and foetal outcomes and limiting excessive gestational weight gain

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340 kcal d^-1 and 452 kcal d^-1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300 kcal d^-1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500 kcal d^-1 and obese women an increase of 0, 450 and 350 kcal day^-1. The recommendations for carbohydrate and protein intake are 175 g d^-1 and 0.88-1.1 g kgBM d^-1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8-11.3 kg and obese women 5.0-9.1 kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5-16.0 kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.

Maternal pelvic dimensions and neonatal size: Implications for growth plasticity in early life as adaptation

Patterns of fetal growth predict non-communicable disease risk in adult life, but fetal growth variability appears to have a relatively weak association with maternal nutritional dynamics during pregnancy. This challenges the interpretation of fetal growth variability as 'adaptation'. We hypothesized that associations of maternal size and nutritional status with neonatal size are mediated by the dimensions of the maternal pelvis. We analysed data on maternal height, body mass index (BMI) and pelvic dimensions (conjugate, inter-spinous and inter-cristal diameters) and neonatal gestational age, weight, length, thorax girth and head girth (n = 224). Multiple regression analysis was used to identify independent maternal predictors of neonatal size, and the mediating role of neonatal head girth in these associations. Pelvic dimensions displaced maternal BMI as a predictor of birth weight, explaining 11.6% of the variance. Maternal conjugate and inter-spinous diameters predicted neonatal length, thorax girth and head girth, whereas inter-cristal diameter only predicted neonatal length. Associations of pelvic dimensions with birth length, but not birth weight, were mediated by neonatal head girth. Pelvic dimensions predicted neonatal size better than maternal BMI, and these associations were mostly independent of maternal height. Sensitivity of fetal growth to pelvic dimensions reduces the risk of cephalo-pelvic disproportion, potentially a strong selective pressure during secular trends in height. Selection on fetal adaptation to relatively inflexible components of maternal phenotype, rather than directly to external ecological conditions, may help explain high levels of growth plasticity during late fetal life and early infancy.

The New "Obstetrical Dilemma": Stunting, Obesity and the Risk of Obstructed Labour

The "obstetrical dilemma" refers to the tight fit between maternal pelvic dimensions and neonatal size at delivery. Most interest traditionally focused on its generic significance for humans, for example our neonatal altriciality and our complex and lengthy birth process. Across contemporary populations, however, the obstetrical dilemma manifests substantial variability, illustrated by differences in the incidence of cephalo-pelvic disproportion, obstructed labour and cesarean section. Beyond accounting for 12% of maternal mortality worldwide, obstructed labour also imposes a huge burden of maternal morbidity, in particular through debilitating birth injuries. This article explores how the double burden of malnutrition and the global obesity epidemic may be reshaping the obstetrical dilemma. First, short maternal stature increases the risk of obstructed labour, while early age at marriage also risks pregnancy before pelvic growth is completed. Second, maternal obesity increases the risk of macrosomic offspring. In some populations, short maternal stature may also promote the risk of gestational diabetes, another risk factor for macrosomic offspring. These nutritional influences are furthermore sensitive to social values relating to issues such as maternal and child nutrition, gender inequality and age at marriage. Secular trends in maternal obesity are substantially greater than those in adult stature, especially in low- and middle-income countries. The association between the dual burden of malnutrition and the obstetrical dilemma is therefore expected to increase, because the obesity epidemic is emerging faster than stunting is being resolved. However, we currently lack objective population-specific data on the association between maternal obesity and birth injuries. Anat Rec, 300:716-731, 2017. © 2017 Wiley Periodicals, Inc.

Birth weight and its relation with medical nutrition therapy in gestational diabetes

PURPOSE

The cornerstone in treatment of gestational diabetes mellitus (GDM) is medical nutrition therapy (MNT), but the effect on birth weight is disputed. The birth weight was evaluated with respect to length of MNT and adherence to diet.

METHODS

We performed a cohort study on 436 women with GDM and 254 non-diabetic women. Women with a normal oral glucose tolerance test were included as controls as they had similar background predisposition as the women with GDM. The GDM women were subdivided according to MNT and the nutritional status was further stratified according to adherence to the current dietary guidelines.

RESULTS

Birth weight above 4 kg was more prevalent in the non-diabetic women compared to the diet-treated GDM women (27 vs. 18%, p = 0.012) but similar to the GDM women who had no MNT (24%). Lower birth weight was associated with longer duration of MNT (r = -0.13, p = 0.021). The birth weight was 1.2 g lower per day of treatment.

CONCLUSIONS

Medical nutrition therapy was associated with reduction of the fetal weight in women with GDM and the weight decreases with length of treatment. Birth weight above 4 kg was as prominent in the non-diabetic women as in the women with GDM without MNT.

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.

Impact of lifestyle intervention for obese women during pregnancy on maternal metabolic and inflammatory markers

BACKGROUND

Offspring of obese mothers have increased risk of developing obesity and related short- and long-term disease. The cause is multifactorial and may partly be explained by the unfavorable intrauterine environment. Intervention during pregnancy leading to a healthier lifestyle among obese may alter this.

OBJECTIVE

To assess the effect of lifestyle intervention on markers of maternal metabolism and inflammation in 'the TOP (Treatment of Obese Pregnant Women) study', a randomized controlled trial.

METHODS

In the TOP-study 425 participants with body mass index ⩾30 kg/m² were randomized to intervention with dietary advices and physical activity assessed by pedometer (PA+D), physical activity assessed by pedometer (PA) or control (C). Of 389 participants completing the study 376 had available blood samples. Serum was analyzed for insulin, c-peptide, lipid profile, leptin, high-sensitivity CRP (hsCRP) and Soluble urokinase Plasminogen Activator Receptor (suPAR), in week 18-20 and 28-30, and simultaneously a 2-h oral glucose-tolerance-test was performed. Diet was assessed in gestational week 11-14 and 36-37 using a validated 360-item Food Frequency Questionnaire.

RESULTS

Median levels of hsCRP in gestational week 28-30 were lower in each of the intervention groups (8.3 mg/l in PA+D group, P=0.03; and 8.8 mg/l in PA group, P=0.02) versus the control group (11.5 mg/l). Obtaining 11 000 steps per day as aimed for resulted in a 21% lower hsCRP compared to non-compliant women. Women reporting high carbohydrate intake had around 30% higher hsCRP concentrations in late gestation than women reporting the lowest intake. There were no differences in lipid profile or any of the metabolic markers in gestational week 28-30 when comparing the intervention and control groups.

CONCLUSIONS

Lifestyle intervention in obese women can reduce hsCRP representing a marker of inflammation during pregnancy. The effect may partly be mediated by more physical activity and partly by changes in intake of carbohydrates and the glycaemic load.

Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a form of diabetes occurring during pregnancy which can result in short- and long-term adverse outcomes for women and babies. With an increasing prevalence worldwide, there is a need to assess strategies, including dietary advice interventions, that might prevent GDM.

OBJECTIVES

To assess the effects of dietary advice interventions for preventing GDM and associated adverse health outcomes for women and their babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (3 January 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of dietary advice interventions compared with no intervention (standard care), or to different dietary advice interventions. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 11 trials involving 2786 women and their babies, with an overall unclear to moderate risk of bias. Six trials compared dietary advice interventions with standard care; four compared low glycaemic index (GI) with moderate- to high-GI dietary advice; one compared specific (high-fibre focused) with standard dietary advice. Dietary advice interventions versus standard care (six trials) Considering primary outcomes, a trend towards a reduction in GDM was observed for women receiving dietary advice compared with standard care (average risk ratio (RR) 0.60, 95% confidence interval (CI) 0.35 to 1.04; five trials, 1279 women; Tau² = 0.20; I² = 56%; P = 0.07; GRADE: very low-quality evidence); subgroup analysis suggested a greater treatment effect for overweight and obese women receiving dietary advice. While no clear difference was observed for pre-eclampsia (RR 0.61, 95% CI 0.25 to 1.46; two trials, 282 women; GRADE: low-quality evidence) a reduction in pregnancy-induced hypertension was observed for women receiving dietary advice (RR 0.30, 95% CI 0.10 to 0.88; two trials, 282 women; GRADE: low-quality evidence). One trial reported on perinatal mortality, and no deaths were observed (GRADE: very low-quality evidence). None of the trials reported on large-for-gestational age or neonatal mortality and morbidity.For secondary outcomes, no clear differences were seen for caesarean section (average RR 0.98, 95% CI 0.78 to 1.24; four trials, 1194 women; Tau² = 0.02; I² = 36%; GRADE: low-quality evidence) or perineal trauma (RR 0.83, 95% CI 0.23 to 3.08; one trial, 759 women; GRADE: very low-quality evidence). Women who received dietary advice gained less weight during pregnancy (mean difference (MD) -4.70 kg, 95% CI -8.07 to -1.34; five trials, 1336 women; Tau² = 13.64; I² = 96%; GRADE: low-quality evidence); the result should be interpreted with some caution due to considerable heterogeneity. No clear differences were seen for the majority of secondary outcomes reported, including childhood/adulthood adiposity (skin-fold thickness at six months) (MD -0.10 mm, 95% CI -0.71 to 0.51; one trial, 132 children; GRADE: low-quality evidence). Women receiving dietary advice had a lower well-being score between 14 and 28 weeks, more weight loss at three months, and were less likely to have glucose intolerance (one trial).The trials did not report on other secondary outcomes, particularly those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood type 2 diabetes; and neurosensory disability. Low-GI dietary advice versus moderate- to high-GI dietary advice (four trials) Considering primary outcomes, no clear differences were shown in the risks of GDM (RR 0.91, 95% CI 0.63 to 1.31; four trials, 912 women; GRADE: low-quality evidence) or large-for-gestational age (average RR 0.60, 95% CI 0.19 to 1.86; three trials, 777 babies; Tau² = 0.61; P = 0.07; I² = 62%; GRADE: very low-quality evidence) between the low-GI and moderate- to high-GI dietary advice groups. The trials did not report on: hypertensive disorders of pregnancy; perinatal mortality; neonatal mortality and morbidity.No clear differences were shown for caesarean birth (RR 1.27, 95% CI 0.79 to 2.04; two trials, 201 women; GRADE: very low-quality evidence) and gestational weight gain (MD -1.23 kg, 95% CI -4.08 to 1.61; four trials, 787 women; Tau² = 7.31; I² = 90%; GRADE: very low-quality evidence), or for other reported secondary outcomes.The trials did not report the majority of secondary outcomes including those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: perineal trauma; postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood adiposity; type 2 diabetes; and neurosensory disability. High-fibre dietary advice versus standard dietary advice (one trial) The one trial in this comparison reported on two secondary outcomes. No clear difference between the high-fibre and standard dietary advice groups observed for mean blood glucose (following an oral glucose tolerance test at 35 weeks), and birthweight.

AUTHORS' CONCLUSIONS

Very low-quality evidence from five trials suggests a possible reduction in GDM risk for women receiving dietary advice versus standard care, and low-quality evidence from four trials suggests no clear difference for women receiving low- versus moderate- to high-GI dietary advice. A possible reduction in pregnancy-induced hypertension for women receiving dietary advice was observed and no clear differences were seen for other reported primary outcomes. There were few outcome data for secondary outcomes.For outcomes assessed using GRADE, evidence was considered to be low to very low quality, with downgrading based on study limitations (risk of bias), imprecision, and inconsistency.More high-quality evidence is needed to determine the effects of dietary advice interventions in pregnancy. Future trials should be designed to monitor adherence, women's views and preferences, and powered to evaluate effects on short- and long-term outcomes; there is a need for such trials to collect and report on core outcomes for GDM research. We have identified five ongoing studies and four are awaiting classification. We will consider these in the next review update.

Is consumption of sugar-sweetened soft drinks during pregnancy associated with birth weight?

In Norway, there were parallel increases and subsequent decreases in birth weight (BW) and consumption of sugar‐sweetened carbonated soft drinks (SSC) during the period 1990–2010, and by an ecological approach, we have suggested that the relationship was causal. The objective of this study was to examine if such a relationship was present in a prospectively followed cohort of pregnant women. The study population included 62,494 term singleton mother–infant dyads in the Norwegian Mother and Child Cohort Study (MoBa), a national prospective cohort study in Norway from 1999 to 2008. The association between SSC consumption and BW was assessed using multiple regression analyses with adjustment for potential confounders. Each 100 ml intake of SSC was associated with a 7.8 g (95% confidence interval [CI]: −10.3 to −5.3) decrease in BW, a decreased risk of BW > 4,500 g (odds ratio [OR]: 0.94, 95% CI: 0.90 to 0.97) and a near significantly increased risk of BW < 2,500 g (OR: 1.05, 95% CI: 0.99 to 1.10). The negative association with SSC consumption was aggravated by smoking, lack of exercise, and obesity. For mothers with gestational diabetes mellitus, we observed an increased risk of BW > 4,500 g (OR: 1.18, 95% CI: 1.00 to 1.39) and a trend towards significant increase in mean BW (25.1 g, 95% CI: −2.0 to 52.2) per 100 ml SSC. Our findings suggest that increasing consumption of rapidly absorbed sugar from SSC had opposite associations with BW in normal pregnancies and pregnancies complicated by gestational diabetes mellitus.

A vegetable, fruit, and white rice dietary pattern during pregnancy is associated with a lower risk of preterm birth and larger birth size in a multiethnic Asian cohort: the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study

BACKGROUND

Maternal dietary patterns during pregnancy have been shown to influence infant birth outcomes. However, to our knowledge, only a few studies have examined the associations in Asian populations.

OBJECTIVE

We characterized maternal dietary patterns in Asian pregnant women and examined their associations with the risk of preterm birth and offspring birth size.

DESIGN

At 26-28 wk of gestation, 24-h recalls and 3-d food diaries were collected from the women in the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort. Dietary patterns were derived from exploratory factor analysis. Gestational age was determined by a dating ultrasound scan in the first trimester, and infant birth anthropometric measurements were obtained from hospital records. Associations were assessed by logistic and linear regressions with adjustment for confounding factors.

RESULTS

Three maternal dietary patterns were identified: vegetable, fruit, and white rice (VFR); seafood and noodle (SfN); and pasta, cheese, and processed meat (PCP). Of 923 infants, 7.6% were born preterm, 13.4% were born small for gestational age, and 14.7% were born large for gestational age. A greater adherence to the VFR pattern (per SD increase in VFR score) was associated with a lower risk of preterm births (OR: 0.67; 95% CI: 0.50, 0.91), higher ponderal index (β: 0.26 kg/m³; 95% CI: 0.06, 0.45 kg/m³), and increased risk of a large-for-gestational-age birth (RR: 1.31; 95% CI: 1.06, 1.62). No associations were observed for the SfN and PCP patterns in relation to birth outcomes.

CONCLUSIONS

The VFR pattern is associated with a lower incidence of preterm birth and with larger birth size in an Asian population. The findings related to larger birth size warrant further confirmation in independent studies. This trial was registered at clinicaltrials.gov as NCT01174875.

Effects of low-glycemic-index diets in pregnancy on maternal and newborn outcomes in pregnant women: a meta-analysis of randomized controlled trials

PURPOSE

Maternal diet with a high glycemic index (GI) is associated with fetal overgrowth and higher infant body adiposity. Effects of low-GI diet on maternal and newborn outcomes have been assessed in both healthy pregnancy and gestational diabetes mellitus, but the results remain inconclusive. This meta-analysis aimed to examine the effects of low-GI diets on maternal and newborn outcomes.

METHODS

PubMed, Clinical Trials, and Cochrane Library databases were searched for relevant randomized trials up to January 2016. Random- or fixed-effects models were used to calculate combined treatment effects.

RESULTS

A total of 11 trials involving 1985 women were eligible for analysis. This meta-analysis assessed 7 maternal and 11 newborn outcomes. Of these, gestational weight gain (GWG), fasting blood glucose (FBG), newborn birth weight, ponderal index (PI), proportion of macrosomia, and large for gestational age (LGA) were investigated in more than 8 trials. Compared with control diets, low-GI diets significantly reduced FBG (weight mean differences (WMD) = -0.18 mmol/L, 95 % CI: -0.33, -0.02), 2-h postprandial glucose level (WMD = -0.33 mmol/L, 95 % CI: -0.54, -0.12), and the proportion of LGA (RR = 0.52, 95 % CI: 0.31, 0.89). A lower GWG (WMD = -0.69 kg, 95 % CI: -1.74, 0.36) and birth weight (WMD = -0.10 kg, 95 % CI: -0.23, 0.03) were also observed without significant differences. Heterogeneity was observed in the GWG, FBG, and birth weight analyses. Low-GI diets did not affect other maternal and newborn outcomes. In subgroup and sensitivity analyses, the intervention effects of low GI on GWG and FBG varied.

CONCLUSIONS

Low-GI diets may have beneficial effects on maternal outcomes for those at risk of developing high glucose levels, without causing adverse effects on newborn outcomes. However, results should be interpreted with caution because of the evidence of heterogeneity and limited number of studies.

Gestational diabetes mellitus: does an effective prevention strategy exist?

The overall incidence of gestational diabetes mellitus (GDM) is increasing worldwide. Preventing pathological hyperglycaemia during pregnancy could have several benefits: a reduction in the immediate adverse outcomes during pregnancy, a reduced risk of long-term sequelae and a decrease in the economic burden to healthcare systems. In this Review we examine the evidence supporting lifestyle modification strategies in women with and without risk factors for GDM, and the efficacy of dietary supplementation and pharmacological approaches to prevent this disease. A high degree of heterogeneity exists between trials so a generalised recommendation is problematic. In population studies of dietary or combined lifestyle measures, risk of developing GDM is not improved and those involving a physical activity intervention have yielded conflicting results. In pregnant women with obesity, dietary modification might reduce fetal macrosomia but in these patients, low compliance and no significant reduction in the incidence of GDM has been observed in trials investigating physical activity. Supplementation with probiotics or myoinositol have reduced the incidence of GDM but confirmatory studies are still needed. In randomized controlled trials, metformin does not prevent GDM in certain at-risk groups. Given the considerable potential for reducing disease burden, further research is needed to identify strategies that can be easily and effectively implemented on a population level.

The association between maternal nutrition and lifestyle during pregnancy and 2-year-old offspring adiposity: analysis from the ROLO study

Aim

To examine the association between maternal nutrition and lifestyle factors and offspring adiposity, using baseline and 2-year postpartum follow-up data from a randomised control trial of low glycaemic index diet.

Subject and methods

Food diaries and lifestyle questionnaires were completed during pregnancy and infant feeding and maternal lifestyle questionnaires 2 years postpartum for 281 mother and infant pairs from the ROLO study. Maternal anthropometry was measured throughout pregnancy and infant and maternal anthropometry was measured 2 years postpartum.

Results

Maternal 2 year postpartum body mass index (BMI) was positively associated with offspring BMI-for-age z-score (B = 0.105, p = 0.015). Trimester 2 saturated fat intake was positively associated with offspring subscapular:triceps skinfold ratio (B = 0.018, p = 0.001). Trimester 1 glycaemic index was also positively associated with offspring sum of subscapular and triceps skinfolds (B = 0.009, p = 0.029).

Conclusions

Maternal BMI 2 years postpartum was positively associated with offspring BMI. Pregnancy saturated fat intake was positively and polyunsaturated fat negatively associated with offspring adiposity. While further research is necessary, pregnancy and the postpartum period may be early opportunities to combat childhood obesity.

Electronic supplementary material

The online version of this article (doi:10.1007/s10389-016-0740-9) contains supplementary material, which is available to authorized users.

Role of nutrition in preventing insulin resistance in children

Nutrition during prenatal, early postnatal and pubertal period is crucial for the development of insulin resistance and its consequences. During prenatal period fetal environment and nutrition seems to interfere with metabolism programming later in life. The type of dietary carbohydrates, glycemic index, protein, fat and micronutrient content in maternal nutrition could influence insulin sensitivity in the newborn. The effects of lactation on metabolism and nutritional behavior later in life have been studied. Dietary habits and quality of diet during puberty could prevent the onset of a pathological insulin resistance through an adequate distribution of macro- and micronutrients, a diet rich in fibers and vegetables and poor in saturated fats, proteins and sugars. We want to overview the latest evidences on the risk of insulin resistance later in life due to both nutritional behaviors and components during the aforementioned periods of life, following a chronological outline from fetal development to adolescence.

Slowly digestible starch--a review

The link between carbohydrate intake and health is becoming increasingly important for consumers, particularly in the areas of glycemic index (GI) and extended energy-releasing starches. From a physiological point of view, slowly digestible starch (SDS) delivers a slow and sustained release of blood glucose along with the benefits resulting from low glycemic and insulinemic response. SDS has been implicated in several health problems, including diabetes, obesity, and cardiovascular diseases (metabolic syndromes). It may also have commercial potential as a novel functional ingredient in a variety of fields, such as nutrition, medicine, and agriculture. The present review assesses this form of digestion by analyzing methods to prepare and evaluate SDS, and factors affecting its transformation, its health benefits, and its applications.

Maternal Nutrition and Glycaemic Index during Pregnancy Impacts on Offspring Adiposity at 6 Months of Age--Analysis from the ROLO Randomised Controlled Trial

Childhood obesity is associated with increased risk of adult obesity and metabolic disease. Diet and lifestyle in pregnancy influence fetal programming; however the influence of specific dietary components, including low glycaemic index (GI), remains complex. We examined the effect of a maternal low GI dietary intervention on offspring adiposity at 6 months and explored the association between diet and lifestyle factors in pregnancy and infant body composition at 6 months. 280 6-month old infant and mother pairs from the control (n = 142) and intervention group (n = 138), who received low GI dietary advice in pregnancy, in the ROLO study were analysed. Questionnaires (food diaries and lifestyle) were completed during pregnancy, followed by maternal lifestyle and infant feeding questionnaires at 6 months postpartum. Maternal anthropometry was measured throughout pregnancy and at 6 months post-delivery, along with infant anthropometry. No difference was found in 6 months infant adiposity between control and intervention groups. Maternal trimester three GI, trimester two saturated fats and trimester one and three sodium intake were positively associated with offspring adiposity, while trimester two and three vitamin C intake was negatively associated. In conclusion associations were observed between maternal dietary intake and GI during pregnancy and offspring adiposity at 6 months of age.

Randomized Controlled Trial Investigating the Effects of a Low-Glycemic Index Diet on Pregnancy Outcomes in Women at High Risk of Gestational Diabetes Mellitus: The GI Baby 3 Study

OBJECTIVE

Dietary interventions can improve pregnancy outcomes in women with gestational diabetes mellitus (GDM). We compared the effect of a low-glycemic index (GI) versus a conventional high-fiber (HF) diet on pregnancy outcomes, birth weight z score, and maternal metabolic profile in women at high risk of GDM.

RESEARCH DESIGN AND METHODS

One hundred thirty-nine women [mean (SD) age 34.7 (0.4) years and prepregnancy BMI 25.2 (0.5) kg/m(2)] were randomly assigned to a low-GI (LGI) diet (n = 72; target GI ∼50) or a high-fiber, moderate-GI (HF) diet (n = 67; target GI ∼60) at 14-20 weeks' gestation. Diet was assessed by 3-day food records and infant body composition by air-displacement plethysmography, and pregnancy outcomes were assessed from medical records.

RESULTS

The LGI group achieved a lower GI than the HF group [mean (SD) 50 (5) vs. 58 (5); P < 0.001]. There were no differences in glycosylated hemoglobin, fructosamine, or lipids at 36 weeks or differences in birth weight [LGI 3.4 (0.4) kg vs. HF 3.4 (0.5) kg; P = 0.514], birth weight z score [LGI 0.31 (0.90) vs. HF 0.24 (1.07); P = 0.697], ponderal index [LGI 2.71 (0.22) vs. HF 2.69 (0.23) kg/m(3); P = 0.672], birth weight centile [LGI 46.2 (25.4) vs. HF 41.8 (25.6); P = 0.330], % fat mass [LGI 10 (4) vs. HF 10 (4); P = 0.789], or incidence of GDM.

CONCLUSIONS

In intensively monitored women at risk for GDM, a low-GI diet and a healthy diet produce similar pregnancy outcomes.