Postprandial Triglycerides Predict Newborn Fat More Strongly than Glucose in Women with Obesity in Early Pregnancy

Influence of maternal α-lipoic acid supplementation in Sprague Dawley rats on maternal and fetal metabolic health in pregnancies complicated by obesity

The objective of this study was to investigate the influence of α-lipoic acid (LA; R enantiomer) supplementation on maternal and fetal metabolic health in pregnancies complicated by maternal obesity. Forty female Sprague-Dawley rats were randomized to one of 4 treatment groups (n=10/group) throughout prepregnancy (3 weeks) and gestation (20 days): (1) a low calorie control (CON); (2) a high calorie obesity-inducing diet (HC); (3) the HC diet with 0.25% LA (HC+LA) or; (4) the HC diet pair-fed to match the caloric intake of the HC+LA group (HC+PF). On gestation day 20, pregnant rats were placed under anesthesia for collection of maternal/fetal blood and tissues. Compared with the HC group, LA-supplemented mothers demonstrated lower maternal prepregnancy and gestational weight gain (GWG), improved glycemic control (lower homeostatic model assessment for insulin resistance), and higher cholesterol concentrations in serum [high-density lipoprotein cholesterol (HDL-C) and low-and very-low density lipoprotein cholesterol (LDL/VLDL) fractions] and liver. Male and female fetuses from LA-supplemented mothers exhibited lower body weight, improved insulin sensitivity, and evidence of altered lipid metabolism including lower serum HDL-C, lower serum triglyceride (TG), and increased hepatic TG accumulation. Although maternal LA supplementation showed some benefit for both mothers and fetuses with respect to obesity and glycemic control, concern about the potential longer-term implications of liver cholesterol (mothers) and TG accumulation (fetuses) needs further investigation.

Association of lipid levels at different stages of pregnancy with gestational diabetes mellitus and the incidence of neonatal macrosomia: A retrospective study

OBJECTIVE

To investigate the correlation between lipid levels during gestation and the incidence rate of gestational diabetes mellitus (GDM) and macrosomia.

METHOD

Clinical records of 607 pregnant women with GDM (GDM group) who delivered in the Obstetrics Department of Fujian Maternal and Child Health Hospital from May to December 2018 and of 833 women with uncomplicated pregnancies (control group) were retrospectively analyzed. After delivery, the entire cohort was further grouped based on the weight of the neonates: women who delivered newborns with body mass <4 kg comprised the normal group (n = 1367), and pregnancies that resulted in delivery of neonates with body mass >4 kg were classified as the macrosomia group (n = 73). Fasting serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and TG/HDL-C ratio were compared between the groups at the early (10-12 weeks), middle (24-28 weeks), and late (28 weeks-delivery) stages of pregnancy, and the correlation between the lipid indices and the rates of GDM and macrosomia were analyzed.

RESULTS

There was a gradual increase in TC, TG, LDL-C, and TG/HDL-C levels with increasing gestational weeks in pregnant women. TG and TG/HDL-C levels were markedly higher, while HDL-C was lower in women with GDM compared with women of the same gestational age with uncomplicated pregnancies (p < 0.05).

CONCLUSION

Lipid metabolism disorders exist in pregnant women with GDM at different gestational stages and are closely related to the higher incidence of macrosomia. TG, TG/HDL-C, and HDL-C in early and late pregnancy are independent risk factors for macrosomia in all trimesters, and TG/HDL-C ratio at different gestational stages has a good predictive value for macrosomia.

Continuous Glucose Monitor Metrics That Predict Neonatal Adiposity in Early and Later Pregnancy Are Higher in Obesity Despite Macronutrient-Controlled Eucaloric Diets

BACKGROUND

Fasting glucose is higher in pregnancies with obesity (OB); less is known about postprandial (PP) and nocturnal patterns when the diet is eucaloric and fixed or about the continuous-glucose-monitor (CGM) metrics that predict neonatal adiposity (NB%fat). We hypothesized that continuous glucose monitors (CGMs) would reveal higher glycemia in OB vs. normal weight (NW) during Early (14-16 weeks) and Later (26-28 weeks) gestation despite macronutrient-controlled eucaloric diets and elucidate unique predictors of NB%fat.

METHODS

In a prospective, parallel-group comparative study, a eucaloric diet (NW: 25 kcal/kg; OB: 30 kcal/kg) was provided (50% carbohydrate [20% simple/30% complex; of total calories], 35% fat, 15% protein) to Early and Later gestation groups wearing a blinded CGM for three days. CGM metrics (mean fasting; 1 h and 2 h PP; daytime and nocturnal glucose; percent time-in-range (%TIR: 63-140 mg/dL); PP excursions; and area-under-the-curve [AUC]) were interrogated between groups and as predictors of NB%fat by dual X-ray absorptiometry(DXA).

RESULTS

Fifty-four women with NW (BMI: 23 kg/m2; n = 27) and OB (BMI: 32; n = 27) provided their informed consent to participate. Early, the daytime glucose was higher in OB vs. NW (mean ± SEM) (91 ± 2 vs. 85 ± 2 mg/dL, p = 0.017), driven by 2 h PP glucose (95 ± 2 vs. 88 ± 2, p = 0.004). Later, those with OB exhibited higher nocturnal (89 ± 2 vs. 81 ± 2), daytime (95 ± 2 vs. 87 ± 2), 1 h (109 ± 3 vs. 98 ± 2), and 2 h PP (101 ± 3 vs. 92 ± 2) glucose (all p < 0.05) but no difference in %TIR (95-99%). Postprandial peak excursions for all meals were markedly blunted in both the Early (9-19 mg/dL) and Later (15-26 mg/dL). In OB, the Later group's 24 h AUC was correlated with NB%fat (r = 0.534, p = 0.02). Despite similar weight gain, infants of OB had higher birthweight (3528 ± 107 vs. 3258 ± 74 g, p = 0.037); differences in NB%fat did not reach statistical significance (11.0 vs. 8.9%; p > 0.05).

CONCLUSIONS

Despite macronutrient-controlled eucaloric diets, pregnancies with OB had higher glycemia Early and Later in gestation; the Later 24 h glucose AUC correlated with NB%fat. However, glycemic patterns were strikingly lower than current management targets.

Lipidomics of infant mesenchymal stem cells associate with the maternal milieu and child adiposity

Our objective was to interrogate mesenchymal stem cell (MSC) lipid metabolism and gestational exposures beyond maternal body mass that may contribute to child obesity risk. MSCs were cultured from term infants of mothers with obesity (n = 16) or normal weight (n = 15). In MSCs undergoing myogenesis in vitro, we used lipidomics to distinguish phenotypes by unbiased cluster analysis and lipid challenge (24-hour excess fatty acid [24hFA]). We measured MSC AMP-activated protein kinase (AMPK) activity and fatty acid oxidation (FAO), and a composite index of maternal glucose, insulin, triglycerides, free fatty acids, TNF-α, and high-density lipoprotein and total cholesterol in fasting blood from mid and late gestation (~17 and ~27 weeks, respectively). We measured child adiposity at birth (n = 29), 4-6 months (n = 29), and 4-6 years (n = 13). Three MSC clusters were distinguished by triacylglycerol (TAG) stores, with greatest TAGs in Cluster 2. All clusters increased acylcarnitines and TAGs with 24hFA, although Cluster 2 was more pronounced and corresponded to AMPK activation and FAO. Maternal metabolic markers predicted MSC clusters and child adiposity at 4-6 years (both highest in Cluster 3). Our data support the notion that MSC phenotypes are predicted by comprehensive maternal metabolic milieu exposures, independent of maternal BMI, and suggest utility as an at-birth predictor for child adiposity, although validation with larger longitudinal samples is warranted.

Maternal Serum Metabolomics in Mid-Pregnancy Identifies Lipid Pathways as a Key Link to Offspring Obesity in Early Childhood

Maternal metabolism during pregnancy shapes offspring health via in utero programming. In the Healthy Start study, we identified five subgroups of pregnant women based on conventional metabolic biomarkers: Reference (n = 360); High HDL-C (n = 289); Dyslipidemic-High TG (n = 149); Dyslipidemic-High FFA (n = 180); Insulin Resistant (IR)-Hyperglycemic (n = 87). These subgroups not only captured metabolic heterogeneity among pregnant participants but were also associated with offspring obesity in early childhood, even among women without obesity or diabetes. Here, we utilize metabolomics data to enrich characterization of the metabolic subgroups and identify key compounds driving between-group differences. We analyzed fasting blood samples from 1065 pregnant women at 18 gestational weeks using untargeted metabolomics. We used weighted gene correlation network analysis (WGCNA) to derive a global network based on the Reference subgroup and characterized distinct metabolite modules representative of the different metabolomic profiles. We used the mummichog algorithm for pathway enrichment and identified key compounds that differed across the subgroups. Eight metabolite modules representing pathways such as the carnitine-acylcarnitine translocase system, fatty acid biosynthesis and activation, and glycerophospholipid metabolism were identified. A module that included 189 compounds related to DHA peroxidation, oxidative stress, and sex hormone biosynthesis was elevated in the Insulin Resistant-Hyperglycemic vs. the Reference subgroup. This module was positively correlated with total cholesterol (R:0.10; p-value < 0.0001) and free fatty acids (R:0.07; p-value < 0.05). Oxidative stress and inflammatory pathways may underlie insulin resistance during pregnancy, even below clinical diabetes thresholds. These findings highlight potential therapeutic targets and strategies for pregnancy risk stratification and reveal mechanisms underlying the developmental origins of metabolic disease risk.

Maternal obesity and placental function: impaired maternal-fetal axis

The prevalence of maternal obesity rapidly increases, which represents a major public health concern worldwide. Maternal obesity is characteristic by metabolic dysfunction and chronic inflammation. It is associated with health problems in both mother and offspring. Increasing evidence indicates that the placenta is an axis connecting maternal obesity with poor outcomes in the offspring. In this brief review, we have summarized the current data regarding deregulated placental function in maternal obesity. The data show that maternal obesity induces numerous placental defects, including lipid and glucose metabolism, stress response, inflammation, immune regulation and epigenetics. These placental defects affect each other and result in a stressful intrauterine environment, which transduces and mediates the adverse effects of maternal obesity to the fetus. Further investigations are required to explore the exact molecular alterations in the placenta in maternal obesity, which may pave the way to develop specific interventions for preventing epigenetic and metabolic programming in the fetus.

Maternal Western-style diet programs skeletal muscle gene expression in lean adolescent Japanese macaque offspring

Early-life exposure to maternal obesity or a maternal calorically dense Western-style diet (WSD) is strongly associated with a greater risk of metabolic diseases in offspring, most notably insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD). Prior studies in our well-characterized Japanese macaque model demonstrated that offspring of dams fed a WSD, even when weaned onto a control (CTR) diet, had reductions in skeletal muscle mitochondrial metabolism and increased skeletal muscle insulin resistance compared to offspring of dams on CTR diet. In the current study, we employed a nested design to test for differences in gene expression in skeletal muscle from lean 3-year-old adolescent offspring from dams fed a maternal WSD in both the presence and absence of maternal obesity or lean dams fed a CTR diet. We included offspring weaned to both a WSD or CTR diet to further account for differences in response to post-weaning diet and interaction effects between diets. Overall, we found that a maternal WSD fed to dams during pregnancy and lactation was the principal driver of differential gene expression (DEG) in offspring muscle at this time point. We identified key gene pathways important in insulin signaling including PI3K-Akt and MAP-kinase, regulation of muscle regeneration, and transcription-translation feedback loops, in both male and female offspring. Muscle DEG showed no measurable difference between offspring of obese dams on WSD compared to those of lean dams fed WSD. A post-weaning WSD effected offspring transcription only in individuals from the maternal CTR diet group but not in maternal WSD group. Collectively, we identify that maternal diet composition has a significant and lasting impact on offspring muscle transcriptome and influences later transcriptional response to WSD in muscle, which may underlie the increased metabolic disease risk in offspring.

Pre-pregnancy body mass index, gestational diabetes mellitus, and gestational weight gain: individual and combined effects on fetal growth

Background

Pre-pregnancy body mass index (BMI), gestational diabetes mellitus (GDM), and gestational weight gain (GWG) are interlinked and may play a complex role in fetal growth. We aimed to examine the relationship between pre-pregnancy BMI, GDM, GWG, and fetal growth outcomes and explore the contribution of GDM and GWG to the relationship between Pre-pregnancy obesity/overweight and large-for-gestational-age (LGA) in a prospective cohort.

Methods

We prospectively recruited women in the first trimester and having one-step GDM screened with a 75-g oral glucose tolerance test between 24 and 28 weeks of gestation (n = 802). Outcomes included LGA, small-for-gestational-age (SGA), and preterm birth. To assess the individual and cumulative associations between pre-pregnancy BMI, GDM, GWG, and these outcomes, we used multivariate logistic regression analysis. Furthermore, we employed structural equation modeling (SEM) to investigate the mediating role of GDM and excessive GWG in the correlation between pre-pregnancy overweight/obesity and LGA.

Results

Pre-pregnancy obesity, GDM, and excessive GWG were all independently associated with increased odds of LGA. Inadequate GWG was associated with higher odds of preterm birth. Compared with women unexposed to pre-pregnancy overweight/obesity, GDM, or excessive GWG, women exposed any two conditions had higher odds for LGA (AOR 3.18, 95% CI 1.25-8.11) and women with coexistence of all had the highest odds for LGA (AOR 8.09, 95% CI 2.18-29.97). The mediation analysis showed that GDM explained 18.60% (p < 0.05) of the total effect of pre-pregnancy overweight/obesity on LGA, and GWG explained 17.44% (p < 0.05) of the total effect.

Conclusion

Pre-pregnancy obesity/overweight, GDM, and excessive GWG are associated with higher odds of fetal growth disturbances as individual factors and when they co-exist. The effect of pre-pregnancy overweight/obesity on LGA is partially achieved through GDM and excessive GWG.

Advances in free fatty acid profiles in gestational diabetes mellitus

The morbidity of gestational diabetes mellitus (GDM) is increasing and is associated with adverse perinatal outcomes and long-term maternal and infant health. The exact mechanism underlying changes in plasma free fatty acid (FFA) profiles in patients with GDM is unknown. However, it is believed that changes in diet and lipid metabolism may play a role. Fatty acids contain many specific FFAs, and the type of FFA has different impacts on physiological processes; hence, determining changes in FFAs in individual plasma is essential. Alterations in FFA concentration or profile may facilitate insulin resistance. Additionally, some FFAs show potential to predict GDM in early pregnancy and are strongly associated with the growth and development of the fetus and occurrence of macrosomia. Here, we aimed to review changes in FFAs in women with GDM and discuss the relationship of FFAs with GDM incidence and adverse outcomes.

Cord blood DNA methylation of immune and lipid metabolism genes is associated with maternal triglycerides and child adiposity

OBJECTIVE

Fetal exposures may impact offspring epigenetic signatures and adiposity. The authors hypothesized that maternal metabolic traits associate with cord blood DNA methylation, which, in turn, associates with child adiposity.

METHODS

Fasting serum was obtained in 588 pregnant women (27-34 weeks' gestation), and insulin, glucose, high-density lipoprotein cholesterol, triglycerides, and free fatty acids were measured. Cord blood DNA methylation and child adiposity were measured at birth, 4-6 months, and 4-6 years. The association of maternal metabolic traits with DNA methylation (429,246 CpGs) for differentially methylated probes (DMPs) and regions (DMRs) was tested. The association of the first principal component of each DMR with child adiposity was tested, and mediation analysis was performed.

RESULTS

Maternal triglycerides were associated with the most DMPs and DMRs of all traits tested (261 and 198, respectively, false discovery rate < 0.05). DMRs were near genes involved in immune function and lipid metabolism. Triglyceride-associated CpGs were associated with child adiposity at 4-6 months (32 CpGs) and 4-6 years (2 CpGs). One, near CD226, was observed at both timepoints, mediating 10% and 22% of the relationship between maternal triglycerides and child adiposity at 4-6 months and 4-6 years, respectively.

CONCLUSIONS

DNA methylation may play a role in the association of maternal triglycerides and child adiposity.

Placental dysfunction in obese women and antenatal surveillance

Obesity is a significant health concern worldwide and is associated with numerous health complications, including placental dysfunction during pregnancy. Placental dysfunction can lead to adverse outcomes for both the mother and the foetus, such as preeclampsia, gestational diabetes, preterm birth, and foetal growth restriction. Studies have shown that maternal obesity can lead to placental dysfunction through various mechanisms, including chronic inflammation, oxidative stress, and dysregulation of metabolic pathways. These factors can contribute to changes in the placenta's structure and function, impairing nutrient and oxygen exchange between the mother and foetus. Recent research has also suggested that alteration of gene expression in the placenta due to epigenetic changes, such as DNA methylation, may play a role in placental dysfunction associated with maternal obesity. These changes can affect altering foetal growth and development. Prevention and management of maternal obesity are crucial in reducing the risk of placental dysfunction and associated adverse outcomes during pregnancy. This can be achieved through lifestyle modifications, such as diet and exercise, and early detection and management of underlying health conditions. In conclusion, maternal obesity is a significant risk factor for placental dysfunction during pregnancy, which can lead to adverse outcomes for both the mother and the foetus. Further research is needed to understand the relationship and mechanisms to develop effective interventions to prevent and manage placental dysfunction in obese pregnant women.

Effects of a High-Fat Diet and Docosahexaenoic Acid during Pregnancy on Fatty Acid Composition in the Fetal Livers of Mice

A high-fat diet (HFD) during pregnancy promotes fat accumulation and reduces docosahexaenoic acid (DHA) levels in the liver of the offspring at postnatal ages, which can depend on fetal sex. However, the prenatal mechanisms behind these associations are still unclear. Thus, we analyzed if an HFD alters DHA content and the expression of molecules related to fatty acid (FA) metabolism in the fetal liver. Female C57BL/6 mice were fed a control diet or HFD for 4-6 weeks before pregnancy until the gestational day (GD) 17.5. A subgroup of each diet received DHA (100 mg/Kg) orally from GD 6.5 until 16.5. On GD 17.5, maternal livers, placentas, and livers from male and female fetuses were collected for FA profiling with gas-chromatography and gene expression of molecules related to FA metabolism using qPCR. PPAR-α protein expression was evaluated using Western blot. The gene expression of placental FA transporters was also assessed. An HFD increased eicosapentaenoic acid (EPA) and decreased DHA levels and protein expression of PPAR-α in the fetal livers of both sexes. DHA increased the gene expression of Ppara, Cpt1, and Acsl1 in the livers of female fetuses. Therefore, an HFD reduces DHA levels and PPAR-α, a master regulator of gene expression, in the fetal liver. In turn, the livers of female fetuses seem to be more sensitive to DHA action.

Metabolomic insights into maternal and neonatal complications in pregnancies affected by type 1 diabetes

AIMS/HYPOTHESIS

Type 1 diabetes in pregnancy is associated with suboptimal pregnancy outcomes, attributed to maternal hyperglycaemia and offspring hyperinsulinism (quantifiable by cord blood C-peptide). We assessed metabolomic patterns associated with risk factors (maternal hyperglycaemia, diet, BMI, weight gain) and perinatal complications (pre-eclampsia, large for gestational age [LGA], neonatal hypoglycaemia, hyperinsulinism) in the Continuous Glucose Monitoring in Women with Type 1 Diabetes in Pregnancy Trial (CONCEPTT).

METHODS

A total of 174 CONCEPTT participants gave ≥1 non-fasting serum sample for the biorepository at 12 gestational weeks (147 women), 24 weeks (167 women) and 34 weeks (160 women) with cord blood from 93 infants. Results from untargeted metabolite analysis (ultrahigh performance LC-MS) are presented as adjusted logistic/linear regression of maternal and cord blood metabolites, risk factors and perinatal complications using a modified Bonferroni limit of significance for dependent variables.

RESULTS

Maternal continuous glucose monitoring time-above-range (but not BMI or excessive gestational weight gain) was associated with increased triacylglycerols in maternal blood and increased carnitines in cord blood. LGA, adiposity, neonatal hypoglycaemia and offspring hyperinsulinism showed distinct metabolite profiles. LGA was associated with increased carnitines, steroid hormones and lipid metabolites, predominantly in the third trimester. However, neonatal hypoglycaemia and offspring hyperinsulinism were both associated with metabolite changes from the first trimester, featuring triacylglycerols or dietary phenols. Pre-eclampsia was associated with increased abundance of phosphatidylethanolamines, a membrane phospholipid, at 24 weeks.

CONCLUSIONS/INTERPRETATION

Altered lipid metabolism is a key pathophysiological feature of type 1 diabetes pregnancy. New strategies for optimising maternal diet and insulin dosing from the first trimester are needed to improve pregnancy outcomes in type 1 diabetes.

Randomization to a Provided Higher-Complex-Carbohydrate Versus Conventional Diet in Gestational Diabetes Mellitus Results in Similar Newborn Adiposity

OBJECTIVE

Nutrition therapy for gestational diabetes mellitus (GDM) has conventionally focused on carbohydrate restriction. In a randomized controlled trial (RCT), we tested the hypothesis that a diet (all meals provided) with liberalized complex carbohydrate (60%) and lower fat (25%) (CHOICE diet) could improve maternal insulin resistance and 24-h glycemia, resulting in reduced newborn adiposity (NB%fat; powered outcome) versus a conventional lower-carbohydrate (40%) and higher-fat (45%) (LC/CONV) diet.

RESEARCH DESIGN AND METHODS

After diagnosis (at ∼28-30 weeks' gestation), 59 women with diet-controlled GDM (mean ± SEM; BMI 32 ± 1 kg/m2) were randomized to a provided LC/CONV or CHOICE diet (BMI-matched calories) through delivery. At 30-31 and 36-37 weeks of gestation, a 2-h, 75-g oral glucose tolerance test (OGTT) was performed and a continuous glucose monitor (CGM) was worn for 72 h. Cord blood samples were collected at delivery. NB%fat was measured by air displacement plethysmography (13.4 ± 0.4 days).

RESULTS

There were 23 women per group (LC/CONV [214 g/day carbohydrate] and CHOICE [316 g/day carbohydrate]). For LC/CONV and CHOICE, respectively (mean ± SEM), NB%fat (10.1 ± 1 vs. 10.5 ± 1), birth weight (3,303 ± 98 vs. 3,293 ± 81 g), and cord C-peptide levels were not different. Weight gain, physical activity, and gestational age at delivery were similar. At 36-37 weeks of gestation, CGM fasting (86 ± 3 vs. 90 ± 3 mg/dL), 1-h postprandial (119 ± 3 vs. 117 ± 3 mg/dL), 2-h postprandial (106 ± 3 vs. 108 ± 3 mg/dL), percent time in range (%TIR; 92 ± 1 vs. 91 ± 1), and 24-h glucose area under the curve values were similar between diets. The %time >120 mg/dL was statistically higher (8%) in CHOICE, as was the nocturnal glucose AUC; however, nocturnal %TIR (63-100 mg/dL) was not different. There were no between-group differences in OGTT glucose and insulin levels at 36-37 weeks of gestation.

CONCLUSIONS

A ∼100 g/day difference in carbohydrate intake did not result in between-group differences in NB%fat, cord C-peptide level, maternal 24-h glycemia, %TIR, or insulin resistance indices in diet-controlled GDM.

Influence of Adipose Tissue on Early Metabolic Programming: Conditioning Factors and Early Screening

BACKGROUND

Obesity and being overweight have become one of the world's most severe health issues, not only because of the pathology but also because of the development of related comorbidities. Even when children reach adulthood, the mother's environment during pregnancy has been found to have a significant impact on obesity prevention in children. Thus, both maternal dietary habits and other factors such as gestational diabetes mellitus, excessive weight gain during pregnancy, smoking, or endocrine factors, among others, could influence newborn growth, adiposity, and body composition at birth, in childhood and adolescence, hence programming health in adulthood.

METHODS

The aim of this review is to analyze the most recent human studies on the programming of fetal adipose tissue to determine which modifiable factors may influence adiposity and thus prevent specific disorders later in life by means of a bibliographic review of articles related to the subject over the last ten years.

CONCLUSIONS

The importance of a healthy diet and lifestyle not only during pregnancy and the first months of life but also throughout childhood, especially during the first two years of life as this is a period of great plasticity, where the foundations for optimal health in later life will be laid, preventing the emergence of noncommunicable diseases including obesity, diabetes mellitus type 2, hypertension, being overweight, and any other pathology linked to metabolic syndrome, which is so prevalent today, through health programs beginning at a young age.

Novel Metabolic Subtypes in Pregnant Women and Risk of Early Childhood Obesity in Offspring

Importance

The in utero metabolic milieu is associated with offspring adiposity. Standard definitions of maternal obesity (according to prepregnancy body mass index [BMI]) and gestational diabetes (GDM) may not be adequate to capture subtle yet important differences in the intrauterine environment that could be involved in programming.

Objectives

To identify maternal metabolic subgroups during pregnancy and to examine associations of subgroup classification with adiposity traits in their children.

Design, Setting, and Participants

This cohort study included mother-offspring pairs in the Healthy Start prebirth cohort (enrollment: 2010-2014) recruited from University of Colorado Hospital obstetrics clinics in Aurora, Colorado. Follow-up of women and children is ongoing. Data were analyzed from March to December 2022.

Exposures

Metabolic subtypes of pregnant women ascertained by applying k-means clustering on 7 biomarkers and 2 biomarker indices measured at approximately 17 gestational weeks: glucose, insulin, Homeostatic Model Assessment for Insulin Resistance, total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, free fatty acids (FFA), HDL-C:triglycerides ratio, and tumor necrosis factor α.

Main Outcomes and Measures

Offspring birthweight z score and neonatal fat mass percentage (FM%). In childhood at approximately 5 years of age, offspring BMI percentile, FM%, BMI in the 95th percentile or higher, and FM% in the 95th percentile or higher.

Results

A total of 1325 pregnant women (mean [SD] age, 27.8 [6.2 years]; 322 [24.3%] Hispanic, 207 non-Hispanic Black [15.6%], and 713 [53.8%] non-Hispanic White), and 727 offspring with anthropometric data measured in childhood (mean [SD] age 4.81 [0.72] years, 48% female) were included. We identified the following 5 maternal metabolic subgroups: reference (438 participants), high HDL-C (355 participants), dyslipidemic-high triglycerides (182 participants), dyslipidemic-high FFA (234 participants), and insulin resistant (IR)-hyperglycemic (116 participants). Compared with the reference subgroup, women in the IR-hyperglycemic and dyslipidemic-high FFA subgroups had offspring with 4.27% (95% CI, 1.94-6.59) and 1.96% (95% CI, 0.45-3.47) greater FM% during childhood, respectively. There was a higher risk of high FM% among offspring of the IR-hyperglycemic (relative risk, 8.7; 95% CI, 2.7-27.8) and dyslipidemic-high FFA (relative risk, 3.4; 95% CI, 1.0-11.3) subgroups; this risk was of greater magnitude compared with prepregnancy obesity alone, GDM alone, or both conditions.

Conclusions and Relevance

In this cohort study, an unsupervised clustering approach revealed distinct metabolic subgroups of pregnant women. These subgroups exhibited differences in risk of offspring adiposity in early childhood. Such approaches have the potential to refine understanding of the in utero metabolic milieu, with utility for capturing variation in sociocultural, anthropometric, and biochemical risk factors for offspring adiposity.

Development and validation of risk prediction models for large for gestational age infants using logistic regression and two machine learning algorithms

BACKGROUND

Large for gestational age (LGA) is one of the adverse outcomes during pregnancy that endangers the life and health of mothers and offspring. We aimed to establish prediction models for LGA at late pregnancy.

METHODS

Data were obtained from an established Chinese pregnant women cohort of 1285 pregnant women. LGA was diagnosed as >90th percentile of birth weight distribution of Chinese corresponding to gestational age of the same-sex newborns. Women with gestational diabetes mellitus (GDM) were classified into three subtypes according to the indexes of insulin sensitivity and insulin secretion. Models were established by logistic regression and decision tree/random forest algorithms, and validated by the data.

RESULTS

A total of 139 newborns were diagnosed as LGA after birth. The area under the curve (AUC) for the training set is 0.760 (95% confidence interval [CI] 0.706-0.815), and 0.748 (95% CI 0.659-0.837) for the internal validation set of the logistic regression model, which consisted of eight commonly used clinical indicators (including lipid profile) and GDM subtypes. For the prediction models established by the two machine learning algorithms, which included all the variables, the training set and the internal validation set had AUCs of 0.813 (95% CI 0.786-0.839) and 0.779 (95% CI 0.735-0.824) for the decision tree model, and 0.854 (95% CI 0.831-0.877) and 0.808 (95% CI 0.766-0.850) for the random forest model.

CONCLUSION

We established and validated three LGA risk prediction models to screen out the pregnant women with high risk of LGA at the early stage of the third trimester, which showed good prediction power and could guide early prevention strategies.

Association of Maternal Metabolites and Metabolite Networks with Newborn Outcomes in a Multi-Ancestry Cohort

The in utero environment is important for newborn size at birth, which is associated with childhood adiposity. We examined associations between maternal metabolite levels and newborn birthweight, sum of skinfolds (SSF), and cord C-peptide in a multinational and multi-ancestry cohort of 2337 mother-newborn dyads. Targeted and untargeted metabolomic assays were performed on fasting and 1 h maternal serum samples collected during an oral glucose tolerance test performed at 24-32 week gestation in women participating in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study. Anthropometric measurements were obtained on newborns at birth. Following adjustment for maternal BMI and glucose, per-metabolite analyses demonstrated significant associations between maternal metabolite levels and birthweight, SSF, and cord C-peptide. In the fasting state, triglycerides were positively associated and several long-chain acylcarnitines were inversely associated with birthweight and SSF. At 1 h, additional metabolites including branched-chain amino acids, proline, and alanine were positively associated with newborn outcomes. Network analyses demonstrated distinct clusters of inter-connected metabolites significantly associated with newborn phenotypes. In conclusion, numerous maternal metabolites during pregnancy are significantly associated with newborn birthweight, SSF, and cord C-peptide independent of maternal BMI and glucose, suggesting that metabolites in addition to glucose contribute to newborn size at birth and adiposity.

Insulin increases placental triglyceride as a potential mechanism for fetal adiposity in maternal obesity

OBJECTIVE

Maternal obesity increases the incidence of excess adiposity in newborns, resulting in lifelong diabetes risk. Elevated intrauterine fetal adiposity has been attributed to maternal hyperglycemia; however, this hypothesis does not account for the increased adiposity seen in newborns of mothers with obesity who have euglycemia. We aimed to explore the placental response to maternal hyperinsulinemia and the effect of insulin-like growth factor 2 (IGF-2) in promoting fetal adiposity by increasing storage and availability of nutrients to the fetus.

METHODS

We used placental villous explants and isolated trophoblasts from normal weight and obese women to assess the effect of insulin and IGF-2 on triglyceride content and insulin receptor signaling. Stable isotope tracer methods were used ex vivo to determine effect of hormone treatment on de novo lipogenesis (DNL), fatty acid uptake, fatty acid oxidation, and esterification in the placenta.

RESULTS

Here we show that placentae from euglycemic women with normal weight and obesity both have abundant insulin receptor. Placental depth and triglyceride were greater in women with obesity compared with normal weight women. In syncytialized placental trophoblasts and villous explants, insulin and IGF-2 activate insulin receptor, induce expression of lipogenic transcription factor SREBP-1 (sterol regulatory element-binding protein 1), and stimulate triglyceride accumulation. We demonstrate elevated triglyceride is attributable to increased esterification of fatty acids, without contribution from DNL and without an acceleration of fatty acid uptake.

CONCLUSIONS

Our work reveals that obesity-driven aberrations in maternal metabolism, such as hyperinsulinemia, alter placental metabolism in euglycemic conditions, and may explain the higher prevalence of excess adiposity in the newborns of obese women.

Associations Between Maternal Lipid Blood Levels at the 13th Week of Pregnancy and Offspring's Adiposity at Age 11-12 Years

CONTEXT

There is increasing evidence that intrauterine lipid metabolism influences the adiposity of the newborn and the first years thereafter. It remains unclear if these effects persist when these children grow older.

OBJECTIVE

This study examined the associations between maternal lipid blood levels during the 13th week of pregnancy and an offspring's adiposity, measured at age 11-12, and if these associations were moderated by the child's sex.

METHODS

Data were obtained from a community-based birth cohort, the Amsterdam Born Children and their Development (ABCD) study. At a median of 13 weeks' gestation, nonfasting blood samples of triglycerides (TGs), total cholesterol (TC), free fatty acids (FFAs), and apolipoprotein B/apolipoprotein A1 ratio (ApoB/ApoA1) were measured. An offspring's body mass index (BMI), subcutaneous fat (SCF), waist-to-height-ratio (WHtR), and fat percentage (fat%) were measured at age 11-12. Mothers with at-term born children were included (n = 1853). Multivariable linear regression analyses were performed to assess the associations between maternal lipids and each offspring's adiposity outcome separately. Sex differences were additionally evaluated.

RESULTS

TGs, TC, ApoB/ApoA1, and FFAs were significantly positively associated with BMI, WHtR, and fat% (adjusted for gestational age at blood sampling, child's age, sex, and sexual maturation). After additional adjustments for potential confounders and covariates, only TGs remained significantly associated with WHtR (0.45, 95% CI -0.007; 0.91). There were no associations between maternal lipids and SCF and no clear sex-specific results were found.

CONCLUSION

Overall, our results do not strongly support that maternal lipid profile during the 13th week of pregnancy has programming effects on adiposity in preadolescence.

Maternal Lipid Metabolism Is Associated With Neonatal Adiposity: A Longitudinal Study

CONTEXT

Pregnancy is characterized by progressive decreases in glucose insulin sensitivity. Low insulin sensitivity resulting in hyperglycemia is associated with higher neonatal adiposity. However, less is known regarding lipid metabolism, particularly lipid insulin sensitivity in pregnancy and neonatal adiposity.

OBJECTIVE

Because higher maternal prepregnancy body mass index is strongly associated with both hyperlipidemia and neonatal adiposity, we aimed to examine the longitudinal changes in basal and clamp maternal lipid metabolism as contributors to neonatal adiposity.

METHODS

Twelve women planning a pregnancy were evaluated before pregnancy, in early (12-14 weeks), and late (34-36 weeks) gestation. Body composition was estimated using hydrodensitometry. Basal and hyperinsulinemic-euglycemic clamp glucose and glycerol turnover (GLYTO) were measured using 2H2-glucose and 2H5-glycerol and substrate oxidative/nonoxidative metabolism with indirect calorimetry. Total body electrical conductivity was used to estimate neonatal body composition.

RESULTS

Basal free-fatty acids decreased with advancing gestation (P = 0.0210); however, basal GLYTO and nonoxidative lipid metabolism increased over time (P = 0.0046 and P = 0.0052, respectively). Further, clamp GLYTO and lipid oxidation increased longitudinally over time (P = 0.0004 and P = 0.0238, respectively). There was a median 50% increase and significant positive correlation during both basal and clamp GLYTO from prepregnancy through late gestation. Neonatal adiposity correlated with late pregnancy basal and clamp GLYTO (r = 0.6515, P = 0.0217; and r = 0.6051, P = 0.0371).

CONCLUSIONS

Maternal prepregnancy and late pregnancy measures of basal and clamp lipid metabolism are highly correlated. Late pregnancy basal and clamp GLYTO are significantly associated with neonatal adiposity and account for ~40% of the variance in neonatal adiposity. These data emphasize the importance of maternal lipid metabolism relating to fetal fat accrual.

Exposure to maternal fuels during pregnancy and offspring hepatic fat in early childhood: The healthy start study

BACKGROUND

Intrauterine overnutrition has been associated with paediatric nonalcoholic fatty liver disease (NAFLD), but the exact mechanisms involved remain unclear.

OBJECTIVE

To examine whether maternal fuels and metabolic markers during pregnancy are associated with offspring hepatic fat in childhood.

METHODS

This analysis included 286 mother-child pairs from the Healthy Start Study, a longitudinal pre-birth cohort in Colorado. Fasting blood draws were collected in early pregnancy (~17 weeks) and mid-pregnancy (~27 weeks). Offspring hepatic fat was assessed by magnetic resonance imaging (MRI) at ~5 years.

RESULTS

In early pregnancy, maternal triglycerides (TGs) and free fatty acids (FFAs) were positively associated with offspring hepatic fat [Back-transformed β (95% CI): 1.15 (1.05, 1.27) per 1 standard deviation (SD) TGs; 1.14 (1.05, 1.23) per 1 SD FFAs]. Maternal total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were also associated with offspring hepatic fat, but only among boys [1.22 (1.08, 1.37) per 1 SD TC; 1.21 (1.07, 1.37) per 1 SD LDL-C]. In mid-pregnancy, only maternal TGs remained associated with offspring hepatic fat. Adjusting for potential confounders or mediators did not affect associations.

CONCLUSIONS

Maternal lipid concentrations, especially in early pregnancy, are associated with higher offspring hepatic fat, and may, therefore, be targeted in future interventions among pregnant women.

Altered Lipid Metabolism in Obese Women With Gestational Diabetes and Associations With Offspring Adiposity

CONTEXT

Gestational diabetes (GDM) affects 20 million women/year worldwide and is associated with childhood obesity. Infants of affected mothers have increased adiposity from birth, which leads to obesity in later life. However, it remains unknown whether the effect of GDM upon neonatal body composition is due to hyperglycemia alone or is mediated by other pathways.

OBJECTIVE

To investigate plasma lipid profiles in obese women according to GDM diagnosis, infant birthweight percentiles, and adiposity.

DESIGN

Prospective cohort from UPBEAT trial (ISRCTN 89971375).

SETTING

Hospital and community.

PATIENTS

867 obese pregnant women recruited in early pregnancy, assessed at 28 weeks for GDM. Offspring anthropometry was assessed at birth.

OUTCOME (PRESPECIFIED)

Neonatal birth percentile and abdominal circumference.

METHODS

Lipidomic profiling in the fasting plasma oral glucose tolerance test sample using direct infusion mass spectrometry. Analysis included logistic/linear regression, unadjusted and adjusted for maternal age, body mass index, parity, ethnicity, UPBEAT trial arm, and fetal sex. The limit of significance was P = 0.05 for offspring anthropometry and P = 0.002 for lipidomic data.

RESULTS

GDM in obese women was associated with elevated plasma concentrations of specific diglycerides [DG(32:0)] and triglycerides [TG(48:0), (50:1), (50:2)] containing fatty acids (16:0), (16:1), (18:0), and (18:1), consistent with increased de novo lipogenesis. In the whole cohort, these species were associated with birthweight percentile and neonatal abdominal circumference. Effects upon infant abdominal circumference remained significant after adjustment for maternal glycemia.

CONCLUSIONS

Increased de novo lipogenesis-related species in pregnant women with obesity and GDM are associated with measures of offspring adiposity and may be a target for improving lifelong health.

The importance of nutrition in pregnancy and lactation: lifelong consequences

Most women in the United States do not meet the recommendations for healthful nutrition and weight before and during pregnancy. Women and providers often ask what a healthy diet for a pregnant woman should look like. The message should be “eat better, not more.” This can be achieved by basing diet on a variety of nutrient-dense, whole foods, including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids that include nuts and seeds, and fish, in place of poorer quality highly processed foods. Such a diet embodies nutritional density and is less likely to be accompanied by excessive energy intake than the standard American diet consisting of increased intakes of processed foods, fatty red meat, and sweetened foods and beverages. Women who report “prudent” or “health-conscious” eating patterns before and/or during pregnancy may have fewer pregnancy complications and adverse child health outcomes. Comprehensive nutritional supplementation (multiple micronutrients plus balanced protein energy) among women with inadequate nutrition has been associated with improved birth outcomes, including decreased rates of low birthweight. A diet that severely restricts any macronutrient class should be avoided, specifically the ketogenic diet that lacks carbohydrates, the Paleo diet because of dairy restriction, and any diet characterized by excess saturated fats. User-friendly tools to facilitate a quick evaluation of dietary patterns with clear guidance on how to address dietary inadequacies and embedded support from trained healthcare providers are urgently needed.

Recent evidence has shown that although excessive gestational weight gain predicts adverse perinatal outcomes among women with normal weight, the degree of prepregnancy obesity predicts adverse perinatal outcomes to a greater degree than gestational weight gain among women with obesity. Furthermore, low body mass index and insufficient gestational weight gain are associated with poor perinatal outcomes. Observational data have shown that first-trimester gain is the strongest predictor of adverse outcomes. Interventions beginning in early pregnancy or preconception are needed to prevent downstream complications for mothers and their children. For neonates, human milk provides personalized nutrition and is associated with short- and long-term health benefits for infants and mothers. Eating a healthy diet is a way for lactating mothers to support optimal health for themselves and their infants.

Maternal lipid profile in pregnancy and embryonic size: a population-based prospective cohort study

Background

Lipids are crucial for fetal growth and development. Maternal lipid concentrations are associated with fetal growth in the second and third trimester of pregnancy and with birth outcomes. However, it is unknown if this association starts early in pregnancy or arises later during fetal development. The aim of this study was to investigate the association between the maternal lipid profile in early pregnancy and embryonic size.

Methods

We included 1474 women from the Generation R Study, a population based prospective birth cohort. Both embryonic size and the maternal lipid profile were measured between 10 weeks + 1 day and 13 weeks + 6 days gestational age. The maternal lipid profile was defined as total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), remnant cholesterol, non-high-density (non-HDL-c) lipoprotein cholesterol concentrations and the triglycerides/high-density lipoprotein (TG/HDL-c) ratio. Additionally, maternal glucose concentrations were assessed. Embryonic size was assessed using crown-rump length (CRL) measurements. Associations were studied with linear regression models, adjusted for confounding factors: maternal age, pre-pregnancy body mass index (BMI), parity, educational level, ethnicity, smoking and folic acid supplement use.

Results

Triglycerides and remnant cholesterol concentrations are positively associated with embryonic size (fully adjusted models, 0.17 SDS CRL: 95% CI 0.03; 0.30, and 0.17 SDS: 95% CI 0.04; 0.31 per 1 MoM increase, respectively). These associations were not present in women with normal weight (triglycerides and remnant cholesterol: fully adjusted model, 0.44 SDS: 95% CI 0.15; 0.72). Associations between maternal lipid concentrations and embryonic size were not attenuated after adjustment for glucose concentrations. Total cholesterol, HDL-c, LDL-c, non-HDL-c concentrations and the TG/HDL-c ratio were not associated with embryonic size.

Conclusions

Higher triglycerides and remnant cholesterol concentrations in early pregnancy are associated with increased embryonic size, most notably in overweight women.

Trial registration

The study protocol has been approved by the Medical Ethics Committee of the Erasmus University Medical Centre (Erasmus MC), Rotterdam (MEC-2007-413). Written informed consent was obtained from all participants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04647-6.

Physiological subtypes of gestational glucose intolerance and risk of adverse pregnancy outcomes

BACKGROUND

Women with gestational glucose intolerance, defined as an abnormal initial gestational diabetes mellitus screening test, are at risk of adverse pregnancy outcomes even if they do not have gestational diabetes mellitus. Previously, we defined the physiological subtypes of gestational diabetes mellitus based on the primary underlying physiology leading to hyperglycemia and found that women with different subtypes had differential risks of adverse outcomes. Physiological subclassification has not yet been applied to women with gestational glucose intolerance.

OBJECTIVE

We defined the physiological subtypes of gestational glucose intolerance based on the presence of insulin resistance, insulin deficiency, or mixed pathophysiology and aimed to determine whether these subtypes are at differential risks of adverse outcomes. We hypothesized that women with the insulin-resistant subtype of gestational glucose intolerance would have the greatest risk of adverse pregnancy outcomes.

STUDY DESIGN

In a hospital-based cohort study, we studied women with gestational glucose intolerance (glucose loading test 1-hour glucose, ≥140 mg/dL; n=236) and normal glucose tolerance (glucose loading test 1-hour glucose, <140 mg/dL; n=1472). We applied homeostasis model assessment to fasting glucose and insulin levels at 16 to 20 weeks' gestation to assess insulin resistance and deficiency and used these measures to classify women with gestational glucose intolerance into subtypes. We compared odds of adverse outcomes (large for gestational age birthweight, neonatal intensive care unit admission, pregnancy-related hypertension, and cesarean delivery) in each subtype to odds in women with normal glucose tolerance using logistic regression with adjustment for age, race and ethnicity, marital status, and body mass index.

RESULTS

Of women with gestational glucose intolerance (12% with gestational diabetes mellitus), 115 (49%) had the insulin-resistant subtype, 70 (27%) had the insulin-deficient subtype, 40 (17%) had the mixed pathophysiology subtype, and 11 (5%) were uncategorized. We found increased odds of large for gestational age birthweight (primary outcome) in women with the insulin-resistant subtype compared with women with normal glucose tolerance (odds ratio, 2.35; 95% confidence interval, 1.43-3.88; P=.001; adjusted odds ratio, 1.74; 95% confidence interval, 1.02-3.48; P=.04). The odds of large for gestational age birthweight in women with the insulin-deficient subtype were increased only after adjustment for covariates (odds ratio, 1.69; 95% confidence interval, 0.84-3.38; P=.14; adjusted odds ratio, 2.05; 95% confidence interval, 1.01-4.19; P=.048). Among secondary outcomes, there was a trend toward increased odds of neonatal intensive care unit admission in the insulin-resistant subtype in an unadjusted model (odds ratio, 2.09; 95% confidence interval, 0.99-4.40; P=.05); this finding was driven by an increased risk of neonatal intensive care unit admission in women with the insulin-resistant subtype and a body mass index of <25 kg/m². Infants of women with other subtypes did not have increased odds of neonatal intensive care unit admission. The odds of pregnancy-related hypertension in women with the insulin-resistant subtype were increased (odds ratio, 2.09; 95% confidence interval, 1.31-3.33; P=.002; adjusted odds ratio, 1.77; 95% confidence interval, 1.07-2.92; P=.03) compared with women with normal glucose tolerance; other subtypes did not have increased odds of pregnancy-related hypertension. There was no difference in cesarean delivery rates in nulliparous women across subtypes.

CONCLUSION

Insulin-resistant gestational glucose intolerance is a high-risk subtype for adverse pregnancy outcomes. Delineating physiological subtypes may provide opportunities for a more personalized approach to gestational glucose intolerance.

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

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

Mechanisms mediating the impact of maternal obesity on offspring hypothalamic development and later function

As obesity rates have risen around the world, so to have pregnancies complicated by maternal obesity. Obesity during pregnancy is not only associated with negative health outcomes for the mother and the baby during pregnancy and birth, there is also strong evidence that exposure to maternal obesity causes an increased risk to develop obesity, diabetes and cardiovascular disease later in life. Animal models have demonstrated that increased weight gain in offspring exposed to maternal obesity is usually preceded by increased food intake, implicating altered neuronal control of food intake as a likely area of change. The hypothalamus is the primary site in the brain for maintaining energy homeostasis, which it coordinates by sensing whole body nutrient status and appropriately adjusting parameters including food intake. The development of the hypothalamus is plastic and regulated by metabolic hormones such as leptin, ghrelin and insulin, making it vulnerable to disruption in an obese in utero environment. This review will summarise how the hypothalamus develops, how maternal obesity impacts on structure and function of the hypothalamus in the offspring, and the factors that are altered in an obese in utero environment that may mediate the permanent changes to hypothalamic function in exposed individuals.

Obesity and pregnancy, the perfect metabolic storm

Pregnancy is a physiological stress that requires dynamic, regulated changes affecting maternal and fetal adiposity. Excessive accumulation of dysfunctional adipose tissue defined by metabolic and molecular alterations cause severe health consequences for mother and fetus. When subjected to sustained overnutrition, the cellular and lipid composition of the adipose tissue changes predisposing to insulin resistance, diabetes, and other metabolic disorders compromising the outcome of the pregnancy. Moreover, excessive maternal weight gain, usually in the context of obesity, predisposes to an increased flux of nutrients from mother to fetus throughout the placenta. The fetus of an obese mother will accumulate more adiposity and may increase the risk of future metabolic disorder later in life. Thus, further understanding of the interaction between maternal metabolism, epigenetic regulation of the adipose tissue, and their transgenerational transfer are required to mitigate the adverse health outcomes for the mother and the fetus associated with maternal obesity.

Metabolic syndrome in obesity: treatment success and adverse pregnancy outcomes with ovulation induction in polycystic ovary syndrome

BACKGROUND

Obesity is common in women with polycystic ovary syndrome. polycystic ovary syndrome and obesity are associated with reduced fertility. The effect of metabolic syndrome on the success of infertility treatment and pregnancy outcomes in women with polycystic ovary syndrome undergoing ovulation induction has not been investigated.

OBJECTIVE

The objectives of this study were to determine the associations of metabolic syndrome on the rate of live birth after ovulation induction and pregnancy complications in obese women with polycystic ovary syndrome and determine whether there is a difference in outcomes concerning specific medications used for ovulation induction.

STUDY DESIGN

This prospective cohort analysis used data collected from participants in the Pregnancy in Polycystic Ovary Syndrome II clinical trial conducted by the Reproductive Medicine Network. In the Pregnancy in Polycystic Ovary Syndrome II trial, 750 women with polycystic ovary syndrome and infertility were randomized to either clomiphene citrate or letrozole for ovulation induction for 1 to 5 cycles or until pregnancy occurred. Cox regression and modified Poisson regression, chi-square test, and Student t test or Wilcoxon test were used in this study. Outcomes of interest were rates of live birth and clinical pregnancy and pregnancy complications. Having metabolic syndrome was defined by the presence of at least 3 of 5 cardiometabolic risk factors (waist circumference of >88 cm, low high-density lipoprotein cholesterol of <50 mg/dL, triglycerides of ≥150 mg/dL, systolic blood pressure of ≥130 or diastolic blood pressure of ≥85 mm Hg, and fasting glucose of >100 mg/dL). In addition, we used a continuous metabolic syndrome z score. Body mass index categories were defined as normal (body mass index of <25 kg/m²), high (25 to 35 kg/m²), and very high (>35 kg/m²).

RESULTS

As illustrated in the Table, early pregnancy losses showed no difference by metabolic syndrome. Fewer women achieved a clinical pregnancy (20.5% vs 29.7%; P=.007) or had a live birth (16.5% vs 27%; P=.001) in the presence of metabolic syndrome. Early pregnancy losses showed no difference by metabolic syndrome status. However, at least 1 pregnancy complication occurred more often with metabolic syndrome: 61.9% (26 of 42 cases) with metabolic syndrome vs 44.4% (59 of 133 cases) (P=.05) without metabolic syndrome. Gestational diabetes mellitus (35.7% vs 18.2%; P=.02) and macrosomia (21.4% vs 8.3%; P=.02) were more common in the presence of metabolic syndrome. After adjustment for other potential confounders, the rate ratio for live births for a 1-unit change in the metabolic syndrome z score was 0.89 (95% confidence interval, 0.79-1.00; P=.04) for those whose body mass index was 25 to 35 kg/m². For the very high body mass index subgroup (>35 kg/m²), the independent effects of metabolic syndrome from obesity were harder to discern. The rate of live birth was higher with the use of letrozole, although metabolic syndrome had a different detrimental effect concerning the medication given. The overall incidence of pregnancy complications was high (approximately 49%) in the Pregnancy in Polycystic Ovary Syndrome II trial and the 2 medications. Letrozole was associated with more obstetrical complications in the presence of metabolic syndrome, and clomiphene was associated with a lower rate of live birth rate when metabolic syndrome was present.

CONCLUSION

Metabolic syndrome is a risk factor that lowers the rate of live birth after ovulation for women with polycystic ovary syndrome, independent of obesity, and it is particularly associated with a lower rate of live birth for women using clomiphene compared with women using letrozole. In addition, metabolic syndrome is a risk factor for pregnancy complications for women with obesity using letrozole. Furthermore, having metabolic syndrome is a risk factor for gestational diabetes mellitus and macrosomia.

Second-trimester maternal lipid profiles rather than glucose levels predict the occurrence of neonatal macrosomia regardless of glucose tolerance status: A matched cohort study in Beijing

AIMS

The mechanism underlying fetal overgrowth during pregnancy remains elusive. We aimed to establish a predictive model to identify the high-risk individuals with macrosomia in the second trimester of pregnancy.

DESIGN

A total of 2577 pregnant women with a routine 75-g oral glucose tolerance test during 24-28 gestational weeks were screened in a prospective cohort. Gestational diabetes mellitus (GDM) cases were 1:1 matching with age (±2 years) in normal glucose tolerance (NGT) ones from the same region. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve were performed to determine the index and its inflection point for predicting macrosomia occurrence.

RESULTS

The data of perinatal outcomes of 565 GDM and 549 NGT who had given birth to single live babies at term were analyzed. Notably, we found serum apolipoprotein B (ApoB) level higher than 4.04 g/L combined with triglycerides (TG)/high-density lipoprotein cholesterol (HDLC) ratio above 1.36 formed the predictive model in both groups. The area under the ROC curve of this predictive model included ApoB and TG/HDL-C reached 0.807 (95% CI: 0.771-0.873) with a sensitivity of 71.9% and a specificity of 78.6%. Mediation analysis revealed that ApoB and TG/HDL-C ratio mediated the harmful effect of FBG on the risk of macrosomia.

CONCLUSION

Maternal ApoB levels and TG/HDL-C ratio could predict macrosomia occurrence in pregnancy, which might be a new target for early intervention to prevent excess fetal growth.

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.

Effect of type 2 diabetes mellitus on placental expression and activity of nutrient transporters and their association with birth weight and neonatal adiposity

AIMS

Infants born to women with Type 2 Diabetes Mellitus (T2DM) are at risk of being born large for gestational age due to excess fetal fat accretion. Placental nutrient transport determines fetal nutrient availability, impacting fetal growth. The aims of the study were to evaluate the effect of T2DM on placental insulin signaling, placental nutrient transporters and neonatal adiposity.

METHODS

Placentas were collected from BMI-matched normoglycemic controls (NGT, n = 9) and T2DM (n = 9) women. Syncytiotrophoblast microvillous (MVM) and basal (BM) plasma membranes were isolated. Expression of glucose (GLUT1, -4), fatty acid (FATP2, -4, -6, FAT/CD36), amino acid (SNAT1, -2, -4, LAT1, -2) transporters, insulin signaling, and System A transporter activity was determined. Neonatal fat mass (%) was measured in a subset of neonates born to T2DM women.

RESULTS

GLUT1 protein expression was increased (p = 0.001) and GLUT4 decreased (p = 0.006) in BM from T2DM. MVM FATP6 expression was increased (p = 0.02) and correlated with birth weight in both T2DM and NGT groups (r = 0.65, p = 0.02). BM FATP6 expression was increased (p = 0.01) in T2DM. In MVM of T2DM placentas, SNAT1 expression was increased (p = 0.05) and correlated with birth weight (r = 0.84, p = 0.004); SNAT2 was increased (p = 0.01), however System A transporter activity was not different between groups. MVM LAT1 expression was increased (p = 0.01) in T2DM and correlated with birth weight (r = 0.59, p = 0.04) and neonatal fat mass (r = 0.76, p = 0.06).

CONCLUSION

In pregnancies complicated by T2DM placental protein expression of transporters for glucose, amino acids and fatty acids is increased, which may contribute to increased fetal growth and neonatal adiposity.

Maternal metabolic health drives mesenchymal stem cell metabolism and infant fat mass at birth

Exposure to maternal obesity may promote metabolic dysfunction in offspring. We used infant mesenchymal stem cells (MSCs) to experimentally examine cellular mechanisms of intergenerational health transmission. Our earlier reports show MSCs collected from infants of mothers with obesity had a dichotomous distribution in metabolic efficiency; they were either efficient (Ef-Ob) or inefficient (In-Ob) with respect to fatty acid oxidation (FAO). Here, we sought to determine if this was due to a primary defect in FAO. Accordingly, we measured FAO in myogenic differentiating MSCs under 3 conditions: (a) myogenesis alone, (b) excess fatty acid exposure, and (c) excess fatty acid exposure plus a chemical uncoupler to increase metabolic rate. Compared with normal weight and Ef-Ob MSCs, In-Ob displayed lower FAO in myogenesis alone and after fatty acid plus uncoupler, indicating In-Ob were less metabolically flexible after increasing lipid availability and metabolic rate, demonstrating a primary deficit in FAO. MSC FAO was negatively associated with fasting maternal glucose and insulin and positively associated with fasting HDL-cholesterol. MSC FAO was negatively associated with infant fat mass. These data indicate a less favorable maternal metabolic milieu, independent of maternal BMI, reduces intrinsic MSC FAO and is linked to higher infant adiposity as early as birth.

Capillary Triglycerides in Late Pregnancy-Challenging to Measure, Hard to Interpret: A Cohort Study of Practicality

BACKGROUND

Maternal triglycerides are increasingly recognised as important predictors of infant growth and fat mass. The variability of triglyceride patterns during the day and their relationship to dietary intake in women in late pregnancy have not been explored. This prospective cohort study aimed to examine the utility of monitoring capillary triglycerides in women in late pregnancy.

METHODS

Twenty-nine women (22 with gestational diabetes (GDM) and 7 without) measured capillary glucose and triglycerides using standard meters at home for four days. On two of those days, they consumed one of two standard isocaloric breakfast meals: a high-fat/low-carbohydrate meal (66% fat) or low fat/high carbohydrate meal (10% fat). Following the standard meals, glucose and triglyceride levels were monitored.

RESULTS

Median capillary triglycerides were highly variable between women but did not differ between GDM and normoglycaemic women. There was variability in capillary triglycerides over four days of home monitoring and a difference in incremental area under the curve for capillary triglycerides and glucose between the two standard meals. The high-fat standard meal lowered the incremental area under the curve for capillary glucose (p < 0.0001). Fasting (rho 0.66, p = 0.0002) and postpradial capillary triglycerides measured at home correlated with venous triglyceride levels.

CONCLUSIONS

The lack of differences in response to dietary fat intake and the correlation between capillary and venous triglycerides suggest that monitoring of capillary triglycerides before and after meals in pregnancy is unlikely to be useful in the routine clinical practice management of women with gestational diabetes mellitus.

Sleep-disordered breathing in pregnancy: a developmental origin of offspring obesity?

Sleep-disordered breathing (SDB) worsens over pregnancy, and obstructive sleep apnea is associated with serious maternal complications. Intrauterine exposures that provoke insulin resistance (IR), inflammation, or oxidative stress may have long-term offspring health consequences. In obesity, worsening maternal SDB appears to be an exposure that increases the risk for both small- or large-for-gestational-age (SGA, LGA, respectively), suggesting distinct outcomes linked to a common maternal phenotype. The aim of this paper is to systematically review and link data from both mechanistic rodent models and descriptive human studies to characterize the impact of maternal SDB on fetal development. A systematic review of the literature was conducted using PubMed, Embase, and CINAHL (01/2000-09/2019). Data from rodent (9 studies) and human models (48 studies, 5 meta-analyses) were included and reviewed using PRISMA guidelines. Evidence from rodent models suggests that intermittent maternal hypoxia results in mixed changes in birth weight (BW) followed by accelerated postnatal growth, while maternal sleep fragmentation results in normal BW followed by later metabolic derangement. Human studies support that maternal SDB is associated with both SGA and LGA, both of which may predispose offspring to later obesity. Evidence also suggests a link between SDB, inflammation, and oxidative stress that may impact maternal metabolism and/or placental function. SDB is common in pregnancy and affects fetal growth and development. Given that SDB has significant potential to adversely influence the intrauterine metabolic environment, larger, prospective studies in humans are urgently needed to fully elucidate the effects of this exposure on offspring metabolic risk.

Hyperglycemia and gestational diabetes suppress placental glycolysis and mitochondrial function and alter lipid processing

The degree that maternal glycemia affects placental metabolism of trophoblast cell types [cytotrophoblast (CTB) and syncytiotrophoblast (SCT)] in pregnant persons with gestational diabetes mellitus (GDM) is unknown. We tested the hypotheses that (a) hyperglycemia suppresses the metabolic rates of CTB and SCT; and (b) low placental metabolic activity from GDM placentas is due to decreased oxygen consumption of CTB. Trophoblast cells isolated from GDM and non-GDM term placentas were cultured for 8-hour (CTB) and following syncytialization at 72-hour (SCT) in 5 mM of glucose or 25 mM of glucose. Oxygen consumption rates, glycolysis, ATP levels, and lipid droplet morphometries were determined in CTB and SCT. In CTB from GDM placentas compared to control CTB: (a) oxidative phosphorylation was decreased by 44% (41.8 vs 74.2 pmol O₂ /min/100 ng DNA, P = .002); (b) ATP content was 39% lower (1.1 × 10^-7 vs 1.8 × 10^-7  nM/ng DNA, P = .046); and (c) lipid droplets were two times larger (31.0 vs 14.4 µm² /cell, P < .001) and 1.7 times more numerous (13.5 vs 7.9 lipid droplets/cell, P < .001). Hyperglycemia suppressed CTB glycolysis by 55%-60% (mean difference 20.4 [GDM, P = .008] and 15.4 [non-GDM, P = .029] mpH/min/100 ng DNA). GDM SCT was not metabolically different from non-GDM SCT. However, GDM SCT had significantly decreased expression of genes associated with differentiation including hCG, GCM1, and syncytin-1. We conclude that suppressed metabolic activity by the GDM placenta is attributable to metabolic dysfunction of CTB, not SCT. Critical placental hormone expression and secretion are decreased in GDM trophoblasts.

Genetic Loci and Physiologic Pathways Involved in Gestational Diabetes Mellitus Implicated Through Clustering

Hundreds of common genetic variants acting through distinguishable physiologic pathways influence the risk of type 2 diabetes (T2D). It is unknown to what extent the physiology underlying gestational diabetes mellitus (GDM) is distinct from that underlying T2D. In this study of >5,000 pregnant women from three cohorts, we aimed to identify physiologically related groups of maternal variants associated with GDM using two complementary approaches that were based on Bayesian nonnegative matrix factorization (bNMF) clustering. First, we tested five bNMF clusters of maternal T2D-associated variants grouped on the basis of physiology outside of pregnancy for association with GDM. We found that cluster polygenic scores representing genetic determinants of reduced β-cell function and abnormal hepatic lipid metabolism were associated with GDM; these clusters were not associated with infant birth weight. Second, we derived bNMF clusters of maternal variants on the basis of pregnancy physiology and tested these clusters for association with GDM. We identified a cluster that was strongly associated with GDM as well as associated with higher infant birth weight. The effect size for this cluster's association with GDM appeared greater than that for T2D. Our findings imply that the genetic and physiologic pathways that lead to GDM differ, at least in part, from those that lead to T2D.

Maternal lipid profile in early pregnancy is associated with foetal growth and the risk of a child born large-for-gestational age: a population-based prospective cohort study : Maternal lipid profile in early pregnancy and foetal growth

BACKGROUND

Lipids such as cholesterol and triglycerides play an important role in both maternal and foetal energy metabolism. Little is known about maternal lipid levels in pregnancy and their effect on foetal growth. The aim of this study was to assess maternal lipid levels, foetal growth and the risk of small-for-gestational age (SGA) and large-for-gestational age (LGA).

METHODS

We included 5702 women from the Generation R Study, a prospective population-based cohort. Maternal lipid levels (total cholesterol, triglycerides and high-density lipoprotein cholesterol [HDL-c]) were measured in early pregnancy (median 13.4 weeks, 90% range [10.5 to 17.2]). Low-density lipoprotein cholesterol (LDL-c), remnant cholesterol and non-HDL-c were calculated. Foetal growth was measured repeatedly by ultrasound. Information on birth anthropometrics was retrieved from medical records. A birth weight below the 10th percentile was defined as SGA and above the 90th percentile as LGA.

RESULTS

Maternal triglyceride and remnant cholesterol levels were associated with increased foetal head circumference and abdominal circumference growth rates. Triglycerides and remnant cholesterol were positively associated with the risk of LGA (odds ratio [OR] 1.11, 95% confidence interval [CI] [1.01 to 1.22] and OR 1.11, 95% CI [1.01 to 1.23], respectively). These associations were independent of maternal pre-pregnancy body mass index, but not maternal glucose levels. We observed no association between maternal lipids in early pregnancy and SGA.

CONCLUSIONS

Our study suggests a novel association of early pregnancy triglyceride and remnant cholesterol levels with foetal growth, patterns of foetal growth and the risk of LGA. Future studies are warranted to explore clinical implication possibilities.

Defining Heterogeneity Among Women With Gestational Diabetes Mellitus

Attention to precision medicine in type 2 diabetes (T2D) has provided two favored approaches to subclassifying affected individuals and parsing heterogeneity apparent in this condition: phenotype-based and genotype-based. Gestational diabetes mellitus (GDM) shares phenotypic characteristics with T2D. However, unlike T2D, GDM emerges in the setting of profound pregnancy-related physiologic changes in glucose metabolism. T2D and GDM also share common genetic architecture, but there are likely to be unique genetic influences on pregnancy glycemic regulation that contribute to GDM. In this Perspective, we describe efforts to decipher heterogeneity in T2D and detail how we and others are applying approaches developed for T2D to the study of heterogeneity in GDM. Emerging results reveal the potential of phenotype- and genotype-based subclassification of GDM to deliver the promise of precision medicine to the obstetric population.

The effects of aerobic exercise on markers of maternal metabolism during pregnancy

BACKGROUND

Optimal maternal metabolism during pregnancy is essential for healthy fetal growth and development. Chronic exercise is shown to positively affect metabolism, predominantly demonstrated in nonpregnant populations.

OBJECTIVE

To determine the effects of aerobic exercise on maternal metabolic biomarkers during pregnancy, with expected lower levels of glucose, insulin, and lipids among exercise-trained pregnant women.

METHODS

Secondary data analyses were performed using data from two, longitudinal prenatal exercise intervention studies (ENHANCED by MOM and GESTAFIT). Exercisers completed 150 min of weekly moderate-intensity exercise during pregnancy (24+ weeks) while nonexercisers attended stretching sessions. Pregnant women were 31-33 years of age, predominantly non-Hispanic white, and "normal weight" body mass index. At 16 and 36 weeks of gestation, fasting blood samples were collected via fingerstick and venipuncture. Maternal glucose, insulin, insulin resistance (HOMA-IR), total cholesterol (TC), low-density lipoproteins (LDL), high-density lipoproteins (HDL), and triglycerides (TG) were analyzed. ANCOVA analyses were performed to evaluate the effects of aerobic exercise on markers of maternal metabolism in late pregnancy, controlling for baseline levels.

RESULTS

Our sample included 12 aerobic exercisers and 54 nonexercising control groups. Significant between-groups differences at 16 weeks of gestation were found for TG (92.3 vs. 121.2 mg/dl, p = .04), TC (186.8 vs. 219.6 mg/dl, p = .002), and LDL (104.1 vs. 128.8 mg/dl, p = .002). Aerobic-trained pregnant women exhibited lower insulin levels in late pregnancy (β = -2.6 μIU/ml, 95% CI:-4.2, -0.95, p = .002) and a reduced increase in insulin levels from 16 to 36 week of gestation (β = -2.3 μIU/ml, 95% CI: -4.4, -0.2, p = .034) compared with nonexercising pregnant women. No statistically significant effects were observed for maternal HOMA-IR, TC, LDL, HDL, TC:HDL, and TG in late pregnancy.

CONCLUSIONS

The observations of this study demonstrate that prenatal exercise may positively affect maternal insulin, with aerobic-trained pregnant women exhibiting lower insulin levels in late pregnancy. Additionally, we found no appreciable effects of prenatal exercise on maternal lipids in late pregnancy.

Type 2 Diabetes in Youth: the Role of Early Life Exposures

PURPOSE OF REVIEW

This review examines the impact of early life exposures on glucose metabolism in the offspring and explores potential metabolic mechanisms leading to type 2 diabetes in childhood.

RECENT FINDINGS

One in five adolescents is diagnosed with prediabetes. Recent studies have elucidated the impact of early exposures such as maternal diabetes, but also hyperglycemia below the threshold of gestational diabetes, obesity, hyperlipidemia, and paternal obesity on the future metabolic health of the offspring. Mechanisms affecting the developmental programing of offspring toward type 2 diabetes include epigenetic modifications, alterations in stem cell differentiation, metabolome and microbiome variation, immune dysregulation, and neonatal nutrition. The risk of type 2 diabetes in offspring is increased not only by diabetes exposure in utero but also by exposure to a heterogeneous milieu of factors that accompany maternal obesity that provoke a vicious cycle of metabolic disease. The key period for intervention to prevent type 2 diabetes is within the first 1000 days of life.

Placental function in maternal obesity

Maternal obesity is associated with pregnancy complications and increases the risk for the infant to develop obesity, diabetes and cardiovascular disease later in life. However, the mechanisms linking the maternal obesogenic environment to adverse short- and long-term outcomes remain poorly understood. As compared with pregnant women with normal BMI, women entering pregnancy obese have more pronounced insulin resistance, higher circulating plasma insulin, leptin, IGF-1, lipids and possibly proinflammatory cytokines and lower plasma adiponectin. Importantly, the changes in maternal levels of nutrients, growth factors and hormones in maternal obesity modulate placental function. For example, high insulin, leptin, IGF-1 and low adiponectin in obese pregnant women activate mTOR signaling in the placenta, promoting protein synthesis, mitochondrial function and nutrient transport. These changes are believed to increase fetal nutrient supply and contribute to fetal overgrowth and/or adiposity in offspring, which increases the risk to develop disease later in life. However, the majority of obese women give birth to normal weight infants and these pregnancies are also associated with activation of inflammatory signaling pathways, oxidative stress, decreased oxidative phosphorylation and lipid accumulation in the placenta. Recent bioinformatics approaches have expanded our understanding of how maternal obesity affects the placenta; however, the link between changes in placental function and adverse outcomes in obese women giving birth to normal sized infants is unclear. Interventions that specifically target placental function, such as activation of placental adiponectin receptors, may prevent the transmission of metabolic disease from obese women to the next generation.

Obesity Reduces Maternal Blood Triglyceride Concentrations by Reducing Angiopoietin-Like Protein 4 Expression in Mice

To ensure fetal lipid supply, maternal blood triglyceride (TG) concentrations are robustly elevated during pregnancy. Interestingly, a lower increase in maternal blood TG concentrations has been observed in some obese mothers. We have shown that high-fat (HF) feeding during pregnancy significantly reduces maternal blood TG levels. Therefore, we performed this study to investigate if and how obesity alters maternal blood TG levels. Maternal obesity was established by prepregnant HF (ppHF) feeding, which avoided the dietary effect during pregnancy. We found not only that maternal blood TG concentrations in ppHF dams were remarkably lower than in control dams but also that the TG peak occurred earlier during gestation. Hepatic TG production and intestinal TG absorption were unchanged in ppHF dams, but systemic lipoprotein lipase (LPL) activity was increased, suggesting that increased blood TG clearance contributes to the decreased blood TG concentrations in ppHF dams. Although significantly higher levels of UCP1 protein were observed in interscapular brown adipose tissue (iBAT) of ppHF dams, Ucp1 gene deletion did not restore blood TG concentrations in ppHF dams. Expression of the angiopoietin-like protein 4 (ANGPTL4), a potent endogenous LPL inhibitor, was significantly increased during pregnancy. However, the pregnancy-induced elevation of blood TG was almost abolished in Angptl4 ^-/- dams. Compared with control dams, Angptl4 mRNA levels were significantly lower in iBAT, gonadal white adipose tissue, and livers of ppHF dams. Importantly, ectopic overexpression of ANGPTL4 restored maternal blood TG concentrations in ppHF dams. Together, these results indicate that ANGPTL4 plays a vital role in increasing maternal blood TG concentrations during pregnancy. Obesity impairs the rise of maternal blood TG concentrations by reducing ANGPTL4 expression in mice.

Effects of Nutrient Intake during Pregnancy and Lactation on the Endocrine Pancreas of the Offspring

The pancreas has an essential role in the regulation of glucose homeostasis by secreting insulin, the only hormone with a blood glucose lowering effect in mammals. Several circulating molecules are able to positively or negatively influence insulin secretion. Among them, nutrients such as fatty acids or amino acids can directly act on specific receptors present on pancreatic beta cells. Dietary intake, especially excessive nutrient intake, is known to modify energy balance in adults, resulting in pancreatic dysfunction. However, gestation and lactation are critical periods for fetal development and pup growth and specific dietary nutrients are required for optimal growth. Feeding alterations during these periods will impact offspring development and increase the risk of developing metabolic disorders in adulthood, leading to metabolic programming. This review will focus on the influence of nutrient intake during gestation and lactation periods on pancreas development and function in offspring, highlighting the molecular mechanism of imprinting on this organ.

Characteristics and pregnancy outcomes across gestational diabetes mellitus subtypes based on insulin resistance

AIMS/HYPOTHESIS

This study aimed to determine the characteristics and pregnancy outcomes across different subtypes of gestational diabetes mellitus (GDM) based on insulin resistance.

METHODS

GDM subtypes were defined in 1813 pregnant women from a multicentre prospective cohort study, stratified according to insulin resistance, based on Matsuda index below the 50th percentile of women with normal glucose tolerance (NGT), during a 75 g OGTT at 24-28 weeks' gestation. GDM was diagnosed in 12.4% (n = 228) of all participants based on the 2013 WHO criteria.

RESULTS

Compared with women with NGT (1113 [61.4%] of the total cohort) and insulin-sensitive women with GDM (39 [17.1%] women with GDM), women with GDM and high insulin resistance (189 [82.9%] women with GDM) had a significantly higher BMI, systolic BP, fasting plasma glucose (FPG), fasting total cholesterol, LDL-cholesterol and triacylglycerol levels in early pregnancy. Compared with women with NGT, insulin-sensitive women with GDM had a significantly lower BMI but similar BP, FPG and fasting lipid levels in early pregnancy. Compared with women with NGT, women with GDM and high insulin resistance had higher rates of preterm delivery (8.5% vs 4.7%, p = 0.030), labour induction (42.7% vs 28.1%, p < 0.001), Caesarean section (total Caesarean sections: 28.7% vs 19.4%, p = 0.004; emergency Caesarean sections: 16.0% vs 9.7%, p = 0.010), neonatal hypoglycaemia (15.4% vs 3.5%, p < 0.001) and neonatal intensive care unit admissions (16.0% vs 8.9%, p = 0.003). In multivariable logistic regression analyses using different models to adjust for demographics, BMI, FPG, HbA_1c, lipid levels and gestational weight gain in early pregnancy, preterm delivery (OR 2.41 [95% CI 1.08, 5.38]) and neonatal hypoglycaemia (OR 4.86 [95% CI 2.04, 11.53]) remained significantly higher in women with GDM and high insulin resistance compared with women with NGT. Insulin-sensitive women with GDM had similar pregnancy outcomes as women with NGT. The need for insulin treatment during pregnancy and the rate of glucose intolerance in the early postpartum period were not significantly different among the GDM subtypes.

CONCLUSIONS/INTERPRETATION

GDM with high insulin resistance represents a more adverse metabolic profile with a greater risk of adverse pregnancy outcomes.

Low-Carbohydrate Diets for Gestational Diabetes

Nutrition therapy provides the foundation for treatment of gestational diabetes (GDM), and has historically been based on restricting carbohydrate (CHO) intake. In this paper, randomized controlled trials (RCTs) are reviewed to assess the effects of both low- and higher CHO nutrition approaches in GDM. The prevailing pattern across the evidence underscores that although CHO restriction improves glycemia at least in the short-term, similar outcomes could be achievable using less restrictive approaches that may not exacerbate IR. The quality of existing studies is limited, in part due to dietary non-adherence and confounding effects of treatment with insulin or oral medication. Recent evidence suggests that modified nutritional manipulation in GDM from usual intake, including but not limited to CHO restriction, improves maternal glucose and lowers infant birthweight. This creates a platform for future studies to further clarify the impact of multiple nutritional patterns in GDM on both maternal and infant outcomes.

Obstructive Sleep Apnea Is Associated With Altered Glycemic Patterns in Pregnant Women With Obesity

OBJECTIVE

Often unrecognized, obstructive sleep apnea (OSA) worsens over pregnancy and is associated with poorer perinatal outcomes. The association between OSA in late pregnancy and metabolic biomarkers remains poorly understood. We tested the hypothesis that OSA in pregnant women with obesity is positively correlated with 24-hour patterns of glycemia and IR despite controlling for diet.

DESIGN

Pregnant women (32 to 34 weeks' gestation; body mass index, 30 to 40 kg/m2) wore a continuous glucose monitor for 3 days. OSA was measured in-home by WatchPAT 200™ [apnea hypopnea index (AHI), oxygen desaturation index (ODI; number per hour)]. Fasting blood was collected followed by a 2-hour, 75-g, oral glucose tolerance test to measure IR. Association between AHI and 24-hour glucose area under the curve (AUC) was the powered outcome.

RESULTS

Of 18 women (29.4 ± 1.4 years of age [mean ± SEM]), 12 (67%) had an AHI ≥5 (mild OSA). AHI and ODI were correlated with 24-hour glucose AUC (r = 0.50 to 0.54; P ≤ 0.03) and mean 24-hour glucose (r = 0.55 to 0.59; P ≤ 0.02). AHI and ODI were correlated with estimated hepatic IR (r = 0.59 to 0.74; P < 0.01), fasting free fatty acids (fFFAs; r = 0.53 to 0.56; P < 0.05), and waking cortisol (r = 0.49 to 0.64; P < 0.05).

CONCLUSIONS

Mild OSA is common in pregnant women with obesity and correlated with increased glycemic profiles, fFFAs, and estimates of hepatic IR. OSA is a potentially treatable target to optimize maternal glycemia and metabolism, fetal fuel supply, and pregnancy outcomes.

Metabolic Culprits in Obese Pregnancies and Gestational Diabetes Mellitus: Big Babies, Big Twists, Big Picture : The 2018 Norbert Freinkel Award Lecture

Pregnancy has been equated to a "stress test" in which placental hormones and growth factors expose a mother's predisposition toward metabolic disease, unleashing her previously occult insulin resistance (IR), mild β-cell dysfunction, and glucose and lipid surplus due to the formidable forces of pregnancy-induced IR. Although pregnancy-induced IR is intended to assure adequate nutrition to the fetus and placenta, in mothers with obesity, metabolic syndrome, or those who develop gestational diabetes mellitus, this overnutrition to the fetus carries a lifetime risk for increased metabolic disease. Norbert Freinkel, nearly 40 years ago, coined this excess intrauterine nutrient exposure and subsequent offspring developmental risk "fuel-mediated teratogenesis," not limited to only excess maternal glucose. Our attempts to better elucidate the causes and mechanisms behind this double-edged IR of pregnancy, to metabolically characterize the intrauterine environment that results in changes in newborn body composition and later childhood obesity risk, and to examine potential therapeutic approaches that might target maternal metabolism are the focus of this article. Rapidly advancing technologies in genomics, proteomics, and metabolomics offer us innovative approaches to interrogate these metabolic processes in the mother, her microbiome, the placenta, and her offspring that contribute to a phenotype at risk for future metabolic disease. If we are successful in our efforts, the researcher, endocrinologist, obstetrician, and health care provider fortunate enough to care for pregnant women have the unique opportunity to positively impact health outcomes not only in the short term but in the long run, not just in one life but in two-and possibly, for the next generation.