Nutritional Lifestyle Intervention in Obese Pregnant Women, Including Lower Carbohydrate Intake, Is Associated With Increased Maternal Free Fatty Acids, 3-β-Hydroxybutyrate, and Fasting Glucose Concentrations: A Secondary Factorial Analysis of the European Multicenter, Randomized Controlled DALI Lifestyle Intervention Trial

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.

The effect of methods used in the management of maternal obesity on pregnancy and birth outcomes: a systematic review with meta-analysis

AIM

This study was conducted to determine the effects of the methods used in the management of maternal obesity on pregnancy and birth outcomes.

MATERIALS AND METHODS

This study was conducted following the PRISMA Statement. The articles to be used in the meta-analysis were searched in PubMed, National Thesis Center, DergiPark, MEDLINE, Cochrane Library and EBSCO search engines in October 2021 and updated in September 2023. The methodological qualities of the studies were evaluated using ROB2. The data were synthesized using meta-analysis, and the GRADE approach was used to rate the certainty of the evidence and the strength of the recommendations. Twenty-one studies published between 2013 and 2021 were included in the study. The total sample size of the studies was 7695.

RESULTS

Weight management interventions significantly reduced weight gain during pregnancy (p < 0.001) and birth weight (p < 0.01). Did not affect other adverse pregnancy outcomes included in the synthesis (p > 0.05). The subgroup analyses showed that the method of handing out brochures resulted in lower levels of birth weight (p < 0.01) and weight gained during pregnancy (p < 0.001); the use of metformin was associated with a significant drop in admissions to the neonatal intensive care unit (p < 0.01); the method of exercise was associated with lower in gestational diabetes (p < 0.001), weight gained during pregnancy (p < 0.001), birth weight (p = 0.01) and large-for-gestational-age baby birth (p < 0.05), while and the combination of diet and exercise significantly reduced weight gained during pregnancy (p = 0.001). The certainty of evidence assessed using GRADE for all 15 critical outcomes was high 15 outcomes.

CONCLUSION

The study revealed that methods used in the treatment of maternal obesity may reduce some negative maternal and newborn outcomes, but it is more important to start pregnancy with an ideal weight.

Mala flavor preference increases risk of excessive gestational weight gain mediated by high-carbohydrate dietary patterns in Chongqing, China: an ambispective cohort study

Taste preference drives food selection, acceptance, or rejection and influences nutritional status and body mass index. Nevertheless, there are few reports concerning pregnant women. Mala flavor, characterized by its "numbing" and "spicy" sensations, is a distinctive taste of Sichuan cuisine, created by the combination of Chinese prickly ash and chili peppers. We conducted a cohort study in Chongqing, China to analyze the impact of Mala flavor, on excessive gestational weight gain (GWG). The study included 495 pregnant women aged 20-45 years, without chronic diseases, who conceived naturally and had single pregnancies from May 2021 to November 2022. Demographic information and pregnancy outcomes were collected during the second trimester and post-delivery, respectively. Food intake and taste preferences, including fatty, salty, and Mala flavors, were assessed during the third trimester. Latent Profile Analysis revealed three dietary patterns: "high-carbohydrate diet" (HCD), "low-carbohydrate diet" (LND), and "moderate nutrient diet" (MND). Multiple logistic regression indicated that pregnant women preferring Mala flavor were more likely to follow an HCD and had a higher risk of excessive GWG. Moreover, those adhering to an HCD were at an increased risk of excessive GWG. Mediation analysis showed that the preference for Mala flavor influenced excessive GWG through HCDs, with a significant indirect effect and an insignificant direct effect. Our study suggests that a preference for Mala flavor is positively associated with excessive GWG, mediated by HCD patterns. However, these findings should be approached with caution due to the exploratory nature of the study.

Excessive palmitic acid disturbs macrophage α-ketoglutarate/succinate metabolism and causes adipose tissue insulin resistance associated with gestational diabetes mellitus

Abnormal polarization of adipose tissue macrophages (ATMs) results in low-grade systemic inflammation and insulin resistance (IR), potentially contributing to the development of diabetes. However, the underlying mechanisms that regulate the polarization of ATMs associated with gestational diabetes mellitus (GDM) remain unclear. Thus, we aimed to determine the effects of abnormal fatty acids on macrophage polarization and development of insulin resistance in GDM. Levels of fatty acids and inflammation were assessed in the serum samples and adipose tissues of patients with GDM. An in vitro cell model treated with palmitic acid was established, and the mechanisms of palmitic acid in regulating macrophage polarization was clarified. The effects of excessive palmitic acid on the regulation of histone methylations and IR were also explored in the high-fat diet induced GDM mice model. We found that pregnancies with GDM were associated with increased levels of serum fatty acids, and inflammation and IR in adipose tissues. Increased palmitic acid could induce mitochondrial dysfunction and excessive ROS levels in macrophages, leading to abnormal cytoplasmic and nuclear metabolism of succinate and α-ketoglutarate (αKG). Specifically, a decreased nuclear αKG/succinate ratio could attenuate the enrichment of H3K27me3 at the promoters of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, leading to cytokine secretion. Importantly, GDM mice treated with GSK-J4, an inhibitor of histone lysine demethylase, were protected from abnormal pro-inflammatory macrophage polarization and excessive production of pro-inflammatory cytokines. Our findings highlight the importance of the metabolism of αKG and succinate as transcriptional modulators in regulating the polarization of ATMs and the insulin sensitivity of adipose tissue, ensuring a normal pregnancy. This novel insight sheds new light on gestational fatty acid metabolism and epigenetic alterations associated with GDM.

Habitual carbohydrate intake is not correlated with circulating β-hydroxybutyrate levels in pregnant women with overweight and obesity at 28 weeks' gestation

AIMS/HYPOTHESIS

Pregnant women are advised to consume a minimum of 175 g per day of carbohydrate to meet maternal and fetal brain glucose requirements. This recommendation comes from a theoretical calculation of carbohydrate requirements in pregnancy, rather than from clinical data. This study aimed to determine whether fasting maternal ketone levels are associated with habitual carbohydrate intake in a subset of participants of the Study of PRobiotics IN Gestational diabetes (SPRING) randomised controlled trial.

METHODS

Food frequency questionnaires on dietary intake during pregnancy were completed by pregnant women with overweight or obesity at 28 weeks' gestation (considering their intake from the beginning of pregnancy). Dietary intake from early pregnancy through to 28 weeks was analysed for macronutrient intake. At the same time, overnight fasting serum samples were obtained and analysed for metabolic parameters including serum β-hydroxybutyrate, OGTTs, insulin and C-peptide.

RESULTS

Fasting serum β-hydroxybutyrate levels amongst 108 women (mean BMI 34.7 ± 6.3 kg/m2) ranged from 22.2 to 296.5 μmol/l. Median fasting β-hydroxybutyrate levels were not different between women with high (median [IQR] 68.4 [49.1-109.2 μmol/l]) and low (65.4 [43.6-138.0 μmol/l]) carbohydrate intake in pregnancy. Fasting β-hydroxybutyrate levels were not correlated with habitual carbohydrate intake (median 155 [126-189] g/day). The only metabolic parameter with which fasting β-hydroxybutyrate levels were correlated was 1 h venous plasma glucose (ρ=0.23, p=0.03) during a 75 g OGTT.

CONCLUSIONS/INTERPRETATION

Fasting serum β-hydroxybutyrate levels are not associated with habitual carbohydrate intake at 28 weeks' gestation in pregnant women with overweight and obesity.

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks' gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

Targeting the gut microbiota and its metabolites for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by hyperglycemia and insulin resistance. The incidence of T2DM is increasing globally, and a growing body of evidence suggests that gut microbiota dysbiosis may contribute to the development of this disease. Gut microbiota-derived metabolites, including bile acids, lipopolysaccharide, trimethylamine-N-oxide, tryptophan and indole derivatives, and short-chain fatty acids, have been shown to be involved in the pathogenesis of T2DM, playing a key role in the host-microbe crosstalk. This review aims to summarize the molecular links between gut microbiota-derived metabolites and the pathogenesis of T2DM. Additionally, we review the potential therapy and treatments for T2DM using probiotics, prebiotics, fecal microbiota transplantation and other methods to modulate gut microbiota and its metabolites. Clinical trials investigating the role of gut microbiota and its metabolites have been critically discussed. This review highlights that targeting the gut microbiota and its metabolites could be a potential therapeutic strategy for the prevention and treatment of T2DM.

[Gestational diabetes mellitus (Update 2023)]

Gestational diabetes (GDM) is defined as any degree of glucose intolerance with onset during pregnancy and is associated with increased feto-maternal morbidity as well as long-term complications in mothers and the offspring. Women detected to have diabetes early in pregnancy receive the diagnosis of overt, non-gestational, diabetes (glucose: fasting ≥ 126 mg/dl, spontaneous ≥ 200 mg/dl or HbA_1c ≥ 6.5% before 20 weeks of gestation). GDM is diagnosed by an oral glucose tolerance test (oGTT) or increased fasting glucose (≥ 92 mg/dl). Screening for undiagnosed type 2 diabetes at the first prenatal visit is recommended in women at increased risk (history of GDM/pre-diabetes; malformation, stillbirth, successive abortions or birth weight > 4500 g previously; obesity, metabolic syndrome, age > 35 years, vascular disease; clinical symptoms of diabetes (e.g. glucosuria) or ethnic origin with increased risk for GDM/T2DM (Arab, South- and Southeast Asian, Latin American)) using standard diagnostic criteria. Performance of the oGTT (120 min; 75 g glucose) may already be indicated in the first trimester in high-risk women but is mandatory between gestational week 24-28 in all pregnant women with previous non-pathological glucose metabolism. Following WHO recommendations, which are based on the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study, GDM is defined, if fasting venous plasma glucose is ≥ 92 mg/dl or 1 h ≥ 180 mg/dl or 2 h ≥ 153 mg/dl after glucose loading (international consensus criteria). In case of one pathological value a strict metabolic control is mandatory. After bariatric surgery we do not recommend to perform an oGTT due to risk of postprandial hypoglycemia. All women with GDM should receive nutritional counseling, be instructed in blood glucose self-monitoring and motivated to increase physical activity to moderate intensity levels-if not contraindicated (Evidence level A). If blood glucose levels cannot be maintained in the therapeutic range (fasting < 95 mg/dl and 1 h after meals < 140 mg/dl, Evidence level B) insulin therapy should be initiated as first choice (Evidence level A). Maternal and fetal monitoring is required in order to minimize maternal and fetal/neonatal morbidity and perinatal mortality. Regular obstetric examinations including ultrasound examinations are recommended (Evidence level A). Neonatal care of GDM offspring at high risk for hypoglycaemia includes blood glucose measurements after birth and if necessary appropriate intervention. Monitoring the development of the children and recommendation of healthy lifestyle are important issues to be tackled for the whole family. After delivery all women with GDM have to be reevaluated as to their glucose tolerance by a 75 g oGTT (WHO criteria) 4-12 weeks postpartum. Assessment of glucose parameters (fasting glucose, random glucose, HbA_1c or optimally oGTT) are recommended every 2-3 years in case of normal glucose tolerance. All women have to be instructed about their increased risk of type 2 diabetes and cardiovascular disease at follow-up. Possible preventive meassures, in particular lifestyle changes as weight management and maintenance/increase of physical activity should be discussed (evidence level A).

Vitamin D3 Supplementation in Overweight/Obese Pregnant Women: No Effects on the Maternal or Fetal Lipid Profile and Body Fat Distribution-A Secondary Analysis of the Multicentric, Randomized, Controlled Vitamin D and Lifestyle for Gestational Diabetes Prevention Trial (DALI)

Vitamin D deficiency is a common finding in overweight/obese pregnant women and is associated with increased risk for adverse pregnancy outcome. Both maternal vitamin D deficiency and maternal obesity contribute to metabolic derangements in pregnancy. We aimed to assess the effects of vitamin D3 supplementation in pregnancy versus placebo on maternal and fetal lipids. Main inclusion criteria were: women <20 weeks’ gestation, BMI ≥ 29 kg/m2. Eligible women (n = 154) were randomized to receive vitamin D3 (1600 IU/day) or placebo. Assessments were performed <20, 24−28 and 35−37 weeks and at birth. Linear regression models were used to assess effects of vitamin D on maternal and cord blood lipids. In the vitamin D group significantly higher total 25-OHD and 25-OHD3 levels were found in maternal and cord blood compared with placebo. Adjusted regression models did not reveal any differences in triglycerides, LDL-C, HDL-C, free fatty acids, ketone bodies or leptin between groups. Neonatal sum of skinfolds was comparable between the two groups, but correlated positively with cord blood 25-OH-D3 (r = 0.34, p = 0.012). Vitamin D supplementation in pregnancy increases maternal and cord blood vitamin D significantly resulting in high rates of vitamin D sufficiency. Maternal and cord blood lipid parameters were unaffected by Vitamin D3 supplementation.

Female infertility and diet, is there a role for a personalized nutritional approach in assisted reproductive technologies? A Narrative Review

Female infertility is a major public health concern and a global challenge. It is a disorder of the reproductive system, defined as the inability to achieve a clinical pregnancy. Nutrition and other environmental factors are found to impact reproductive health in women as well as the outcome of assisted reproductive technologies (ART). Dietary factors, such as polyunsaturated fatty acids (PUFA), fiber as well as the intake of Mediterranean diet appear to exert beneficial effects on female reproductive outcomes. The exact mechanisms associating diet to female fertility are yet to be identified, although genomic, epigenomic, and microbial pathways may be implicated. This review aims to summarize the current knowledge on the impact of dietary components on female reproduction and ART outcomes, and to discuss the relevant interplay of diet with genome, epigenome and microbial composition.

Effectiveness of five interventions used for prevention of gestational diabetes: A network meta-analysis

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with short- and long-term health issues for mother and child; preventing these complications is crucially important. This study aimed to perform a systematic review and network meta-analysis of the relationships among 5 interventions used to prevent GDM.

MATERIALS AND METHODS

A comprehensive literature search was performed to pool evidence from inception to June 30, 2020. The type of studies was confined to randomized control trials and quasi-randomized control trials published in English investigating the interventions for preventing GDM, including physical activity, dietary intervention, probiotic intervention, mixed intervention, and inositol supplementation. The data were pooled together to report the odds ratio (OR) of GDM with a corresponding 95% credible interval (CrI) and generate a network plot, the surface under the cumulative ranking curve plot, and contribution plot. In addition, loop inconsistency was examined, and a funnel plot combined with Egger test was used to measure heterogeneity.

RESULTS

The network meta-analysis included 46 randomized control trials involving 16,545 patients. Compared with placebo, physical activity (OR: 0.64, 95% CrI: 0.46-0.88) and probiotic intervention (OR: 0.57, 95% CrI: 0.34-0.96) reduced the incidence of GDM significantly. However, dietary intervention, a combination of physical activity and diet intervention, and inositol supplementation did not significantly alter GDM risk.

CONCLUSIONS

Physical activity and probiotic intervention are more effective than placebo in reducing the risk of developing GDM. Future work should focus on the type, duration, frequency, and timing of physical activity and probiotic intervention.

Interaction between rs10830962 polymorphism in MTNR1B and lifestyle intervention on maternal and neonatal outcomes: secondary analyses of the DALI lifestyle randomized controlled trial

BACKGROUND

Interactions between polymorphisms of the melatonin receptor 1B (MTNR1B) gene and lifestyle intervention for gestational diabetes have been described. Whether these are specific for physical activity or the healthy eating intervention is unknown.

OBJECTIVES

The aim was to assess the interaction between MTNR1B rs10830962 and rs10830963 polymorphisms and lifestyle interventions during pregnancy.

METHODS

Women with a BMI (in kg/m2) of ≥29 (n = 436) received counseling on healthy eating (HE), physical activity (PA), or both. The control group received usual care. This secondary analysis had a factorial design with comparison of HE compared with no HE and PA compared with no PA. Maternal outcomes at 24-28 wk were gestational weight gain (GWG), maternal fasting glucose, insulin, insulin resistance (HOMA-IR), disposition index, and development of GDM. Neonatal outcomes were cord blood leptin and C-peptide and estimated neonatal fat percentage. The interaction between receiving either the HE or PA intervention and genotypes of both rs10830962 and rs10830963 was assessed using multilevel regression analysis.

RESULTS

GDM risk was increased in women homozygous for the G allele of rs10830962 (OR: 2.60; 95% CI: 1.34, 5.06) or rs10830963 (OR: 2.83; 95% CI: 1.24, 6.47). Significant interactions between rs10830962 and interventions were found: in women homozygous for the G allele but not in the other genotypes, the PA intervention reduced maternal fasting insulin (β: -0.16; 95% CI: -0.33, 0.02; P = 0.08) and HOMA-IR (β: -0.17; 95% CI: -0.35, 0.01; P = 0.06), and reduced cord blood leptin (β: -0.84; 95% CI: -1.42, -0.25; P = 0.01) and C-peptide (β: -0.62; 95% CI: -1.07, -0.17; P = 0.01). In heterozygous women, the HE intervention had no effect, whereas in women homozygous for the C allele, HE intervention reduced GWG (β: -1.6 kg; 95% CI: -2.4, -0.8 kg). No interactions were found.

CONCLUSIONS

In women homozygous for the risk allele of MTNR1B rs10830962, GDM risk was increased and PA intervention might be more beneficial than HE intervention for reducing maternal insulin resistance, cord blood C-peptide, and cord blood leptin.

The role of maternal diet on offspring hyperinsulinaemia and adiposity after birth: a systematic review of randomised controlled trials

In utero diet may be directly related to the risk of fetal hyperinsulinaemia and offspring metabolic health. This review examines the relationship between maternal dietary exposures and sub-clinical fetal hyperinsulinaemia and neonatal adiposity. Articles were identified in MEDLINE, Web of Science, Cochrane Controlled Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, SCOPUS, and SPORTDiscus (September 2019-March 2021) using the preferred reporting items for systematic reviews and meta-analyses guidelines. PROSPERO registration ID CRD42020146453. Studies were selected by two independent reviewers. Randomised controlled trials (RCT) involving a dietary intervention with pregnant women (healthy pregnancy, gestational diabetes mellitus and obesity) and reporting fetal cord-blood insulin, c-peptide, glucose or adiposity estimates were included. One author extracted all information on main study characteristics and outcomes. Risk of bias was assessed using the Cochrane Collaboration's bias risk assessment tool. A total of 733 articles were identified. Fourteen articles from 11 RCTs (3614 participants) were included. Studies reviewed showed no specific effect of maternal diet on neonatal cord blood insulin, c-peptide or glucose levels. Infants born to mothers who followed a low glycaemic load (GL) had lower skin fold thickness compared to controls. Interventions that provided individualised nutrition counselling to women with obesity or previous infant born > 4 kg were also associated with lower adiposity. The studies reviewed suggest that lifestyle-based dietary interventions to improve glycaemia (low GL) have a protective effect against excess adiposity. Future studies should incorporate multi-modal interventions with dietary counselling to support lifestyle changes throughout gestation and include assessments of maternal insulin resistance at recruitment.

The Role of Short-Chain Fatty Acids in Mediating Very Low-Calorie Ketogenic Diet-Infant Gut Microbiota Relationships and Its Therapeutic Potential in Obesity

As the very low-calorie ketogenic diet (VLCKD) gains increased interest as a therapeutic approach for many diseases, little is known about its therapeutic use in childhood obesity. Indeed, the role of VLCKD during pregnancy and lactation in influencing short chain fatty acid (SCFA)-producing bacteria and the potential mechanisms involved in the protective effects on obesity are still unclear. Infants are characterized by a diverse gut microbiota composition with higher abundance of SCFA-producing bacteria. Maternal VLCKD during pregnancy and lactation stimulates the growth of diverse species of SCFA-producing bacteria, which may induce epigenetic changes in infant obese gene expression and modulate adipose tissue inflammation in obesity. Therefore, this review aims to determine the mechanistic role of SCFAs in mediating VLCKD-infant gut microbiota relationships and its protective effects on obesity.

The Carbohydrate Threshold in Pregnancy and Gestational Diabetes: How Low Can We Go?

The original nutrition approach for the treatment of gestational diabetes mellitus (GDM) was to reduce total carbohydrate intake to 33-40% of total energy (EI) to decrease fetal overgrowth. Conversely, accumulating evidence suggests that higher carbohydrate intakes (60-70% EI, higher quality carbohydrates with low glycemic index/low added sugars) can control maternal glycemia. The Institute of Medicine (IOM) recommends ≥175 g/d of carbohydrate intake during pregnancy; however, many women are consuming lower carbohydrate (LC) diets (<175 g/d of carbohydrate or <40% of EI) within pregnancy and the periconceptual period aiming to improve glycemic control and pregnancy outcomes. This report systematically evaluates recent data (2018-2020) to identify the LC threshold in pregnancy in relation to safety considerations. Evidence from 11 reports suggests an optimal carbohydrate range of 47-70% EI supports normal fetal growth; higher than the conventionally recognized LC threshold. However, inadequate total maternal EI, which independently slows fetal growth was a frequent confounder across studies. Effects of a carbohydrate intake <175 g/d on maternal ketonemia and plasma triglyceride/free fatty acid concentrations remain unclear. A recent randomized controlled trial (RCT) suggests a higher risk for micronutrient deficiency with carbohydrate intake ≤165 g/d in GDM. Well-controlled prospective RCTs comparing LC (<165 g/d) and higher carbohydrate energy-balanced diets in pregnant women are clearly overdue.

The importance of maternal insulin resistance throughout pregnancy on neonatal adiposity

BACKGROUND

Although previous studies evaluated the association of maternal health parameters with neonatal adiposity, little is known regarding the complexity of the relationships among different maternal health parameters throughout pregnancy and its impact on neonatal adiposity.

OBJECTIVES

To evaluate the direct and indirect associations between maternal insulin resistance during pregnancy, in women with obesity, and neonatal adiposity. In addition, associations between maternal fasting glucose, triglycerides (TG), non-esterified fatty acids (NEFA), and neonatal adiposity were also assessed.

METHODS

This is a longitudinal, secondary analysis of the DALI study, an international project conducted in nine European countries with pregnant women with obesity. Maternal insulin resistance (HOMA-IR), fasting glucose, TG, and NEFA were measured three times during pregnancy (<20, 24-28, and 35-37 weeks of gestation). Offspring neonatal adiposity was estimated by the sum of four skinfolds. Structural equation modelling was conducted to evaluate the direct and indirect relationships among the variables of interest.

RESULTS

Data on 657 mother-infant pairs (50.7% boys) were analysed. Neonatal boys exhibited lower mean sum of skinfolds compared to girls (20.3 mm, 95% CI 19.7, 21.0 vs 21.5 mm, 95% CI 20.8, 22.2). In boys, maternal HOMA-IR at <20 weeks was directly associated with neonatal adiposity (β = 0.35 mm, 95% CI 0.01, 0.70). In girls, maternal HOMA-IR at 24-28 weeks was only indirectly associated with neonatal adiposity, which implies that this association was mediated via maternal HOMA-IR, glucose, triglycerides, and NEFA during pregnancy (β = 0.26 mm, 95% CI 0.08, 0.44).

CONCLUSIONS

The timing of the role of maternal insulin resistance on neonatal adiposity depends on fetal sex. Although the association was time-dependent, maternal insulin resistance was associated with neonatal adiposity in both sexes.

Effect of Elevated Ketone Body on Maternal and Infant Outcome of Pregnant Women with Abnormal Glucose Metabolism During Pregnancy

Ketone bodies are one of the products of fat metabolism which can be used as an alternative energy source for the human body in states of glucose deficiency. Normal pregnant women may develop ketosis due to physiological changes during pregnancy, while pregnant women with abnormal glucose metabolism are more likely to develop ketosis due to abnormal insulin secretion. Animal experiments and clinical studies have shown that exposure to high-ketone environments during pregnancy is closely related to adverse maternal and infant outcomes. However, there is no unified conclusion on whether ketone bodies should be routinely monitored during pregnancy. This review summarizes the existing studies on ketone body levels and pregnancy outcomes in the case of abnormal blood glucose during pregnancy, elaborates the current guidelines on the level of ketone bodies, provides the detection and treatment of ketosis in pregnant women with abnormal blood glucose in the clinical practice.

Effects of a modestly lower carbohydrate diet in gestational diabetes: a randomized controlled trial

BACKGROUND

Lower carbohydrate diets have the potential to improve glycemia but may increase ketonemia in women with gestational diabetes (GDM). We hypothesized that modestly lower carbohydrate intake would not increase ketonemia.

OBJECTIVE

To compare blood ketone concentration, risk of ketonemia, and pregnancy outcomes in women with GDM randomly assigned to a lower carbohydrate diet or routine care.

METHODS

Forty-six women aged (mean ± SEM) 33.3 ± 0.6 y and prepregnancy BMI 26.8 ± 0.9 kg/m2 were randomly assigned at 28.5 ± 0.4 wk to a modestly lower carbohydrate diet (MLC, ∼135 g/d carbohydrate) or routine care (RC, ∼200 g/d) for 6 wk. Blood ketones were ascertained by finger prick test strips and 3-d food diaries were collected at baseline and end of the intervention.

RESULTS

There were no detectable differences in blood ketones between completers in the MLC group compared with the RC group (0.1 ± 0.0 compared with 0.1 ± 0.0 mmol/L, n = 33, P = 0.31, respectively), even though carbohydrate and total energy intake were significantly lower in the intervention group (carbohydrate 165 ± 7 compared with 190 ± 9 g, P = 0.04; energy 7040 ± 240 compared with 8230 ± 320 kJ, P <0.01, respectively). Only 20% of participants in the MLC group met the target intake compared with 65% in the RC group (P <0.01). There were no differences in birth weight, rate of large-for-gestational-age infants, percent fat mass, or fat-free mass between groups.

CONCLUSIONS

An intervention to reduce carbohydrate intake in GDM did not raise ketones to clinical significance, possibly because the target of 135 g/d was difficult to achieve in pregnancy. Feeding studies with food provision may be needed to assess the benefits and risks of low-carbohydrate diets. This trial was registered at www.anzctr.org.au as ACTRN12616000018415.

Markers for undiagnosed type 2 diabetes mellitus during pregnancy-A population-based retrospective cohort study

BACKGROUND

To examine possible markers for undiagnosed type 2 diabetes in early-onset gestational diabetes mellitus (GDM).

METHODS

A population-based retrospective cohort study of women with GDM diagnosed prior to the 24th week, who delivered between 2005 and 2018, was conducted. The results of the 50-g glucose challenge test, 100-g oral glucose tolerance test, and the first available glycosylated hemoglobin (HbA1c) were examined as markers for type 2 diabetes diagnosed 6 to 12 weeks post pregnancy, which is suggestive of pregestational diabetes. This was done by calculating the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for each marker. These markers and additional ones were evaluated for independency by stepwise multivariate logistic regression.

RESULTS

Of 69 417 pregnancies, 3321 (5%) pregnancies were with GDM. Of them, in 261 (8%) women GDM was diagnosed prior to the 24th week, and 219 (84%) women had available data for analysis. Among them, 11 (5%) women had type 2 diabetes post pregnancy. Elevated HbA1c was the most accurate marker for undiagnosed type 2 diabetes (AUC 91% with 95% CI [81%-100%]) and the only independent marker for undiagnosed type 2 diabetes in multivariate analysis (odds ratio [OR] 19; 95% CI [3.2-109], C statistic = 88%). Using the ROC curve, a cutoff of 5.8% predicted type 2 diabetes with 89% sensitivity, 86% specificity, 99.4% negative predictive value, and 23% positive predictive value.

CONCLUSIONS

Early-onset GDM with HbA1c ≥ 5.8% should be managed as type 2 diabetes. Definitive diagnosis should be done after delivery.

The Effects of Lifestyle and/or Vitamin D Supplementation Interventions on Pregnancy Outcomes: What Have We Learned from the DALI Studies?

PURPOSE OF REVIEW

The DALI (vitamin D and lifestyle intervention in the prevention of gestational diabetes mellitus (GDM)) study aimed to prevent GDM with lifestyle interventions or Vitamin D supplementation (1600 IU/day). This review summarizes the learnings from the DALI studies among pregnant women with a BMI ≥ 29 kg/m².

RECENT FINDINGS

Women diagnosed with GDM earlier in pregnancy had a worse metabolic profile than those diagnosed later. A combined physical activity (PA) and healthy eating (HE) lifestyle intervention improved both behaviours, limited gestational weight gain (GWG) and was cost-effective. Although GDM risk was unchanged, neonatal adiposity was reduced due to less sedentary time. Neither PA nor HE alone limited GWG or GDM risk. Fasting glucose was higher with HE only intervention, and lower with Vitamin D supplementation. Our combined intervention did not prevent GDM, but was cost-effective, limited GWG and reduced neonatal adiposity.

GDM and Nutrition-Answered and Unanswered Questions-There's More Work to Do!

Gestational Diabetes Mellitus (GDM) is the commonest medical pregnancy complication, and a growing problem around the world as the obesity epidemic continues. Ways to prevent GDM are urgently required, the management of GDM still poses many unanswered questions, and the postpartum prevention of the progression of GDM to type 2 diabetes remains a challenge. With GDM, the impact of any intervention on the offspring is always a major concern. Nutritional interventions come to the fore as one of our few levers in reducing the short-term pregnancy risk and long-term cardiometabolic risks to both mother and child. This special issue reports on the relationship between several nutrients and foods and the development and management of GDM, behavioural strategies to enhance lifestyle choices, the issues raised by prior bariatric surgery and ways to screen for GDM. The work identifies further unanswered questions over nutritional strategies to reduce the impact of GDM.