Neonatal morbidities among full-term infants born to obese mothers

Metabolic abnormalities in the bone marrow cells of young offspring born to obese mothers

Intrauterine metabolic reprogramming occurs in obese mothers during gestation, putting the offspring at high risk of developing obesity and associated metabolic disorders even before birth. We have generated a mouse model of maternal high-fat diet-induced obesity that recapitulates the metabolic changes seen in humans. Here, we profiled and compared the metabolic characteristics of bone marrow cells of newly weaned 3-week-old offspring of dams fed either a high-fat (Off-HFD) or a regular diet (Off-RD). We utilized a state-of-the-art targeted metabolomics approach coupled with a Seahorse metabolic analyzer. We revealed significant metabolic perturbation in the offspring of HFD-fed vs. RD-fed dams, including utilization of glucose primarily via oxidative phosphorylation, and reduction in levels of amino acids, a phenomenon previously linked to aging. Furthermore, in the bone marrow of three-week-old offspring of high-fat diet-fed mothers, we identified a unique B cell population expressing CD19 and CD11b, and found increased expression of Cyclooxygenase-2 (COX-2) on myeloid CD11b, and on CD11b hi B cells, with all the populations being significantly more abundant in offspring of dams fed HFD but not a regular diet. Altogether, we demonstrate that the offspring of obese mothers show metabolic and immune changes in the bone marrow at a very young age and prior to any symptomatic metabolic disease.

Maternal high-fat diet changes breathing pattern and causes excessive sympathetic discharge in juvenile offspring rat

Early life over-nutrition, as experienced in maternal obesity, is a risk factor for developing cardiorespiratory and metabolic diseases. Here we investigated the effects of high-fat diet (HFD) consumption on the breathing pattern and sympathetic discharge to blood vessels in juvenile offspring from dams fed with HFD (O-HFD). Adult female Holtzman rats were given a standard diet (SD) or HFD from 6 wk before gestation to weaning. At weaning (P21), the male offspring from SD dams (O-SD) and O-HFD received SD until the experimental day (P28-P45). Nerve recordings performed in decerebrated in situ preparations demonstrated that O-HFD animals presented abdominal expiratory hyperactivity under resting conditions and higher vasoconstrictor sympathetic activity levels. The latter was associated with blunted respiratory-related oscillations in sympathetic activity, especially in control animals. When exposed to elevated hypercapnia or hypoxia levels, the O-HFD animals mounted similar ventilatory and respiratory motor responses as the control animals. Hypercapnia and hypoxia exposure also increased sympathetic activity in both groups but did not reinstate the respiratory-sympathetic coupling in the O-HFD rats. In freely behaving conditions, O-HFD animals exhibited higher resting pulmonary ventilation and larger variability of arterial pressure levels than the O-SD animals due to augmented sympathetic modulation of blood vessel diameter. Maternal obesity modified the functioning of cardiorespiratory systems in offspring at a young age, inducing active expiration and sympathetic overactivity under resting conditions. These observations represent new evidence about pregnancy-related complications that lead to the development of respiratory distress and hypertension in children of obese mothers.NEW & NOTEWORTHY Maternal obesity is a risk factor for developing cardiorespiratory and metabolic diseases. This study highlights the changes on the breathing pattern and sympathetic discharge to blood vessels in juvenile offspring from dams fed with HFD. Maternal obesity modified the functioning of cardiorespiratory systems in offspring, inducing active expiration and sympathetic overactivity. These observations represent new evidence about pregnancy-related complications that lead to the development of respiratory distress and hypertension in children of obese mothers.

Multimodal profiling of term human decidua demonstrates immune adaptations with pregravid obesity

Leukocyte diversity of the first-trimester maternal-fetal interface has been extensively described; however, the immunological landscape of the term decidua remains poorly understood. We therefore profiled human leukocytes from term decidua collected via scheduled cesarean delivery. Relative to the first trimester, our analyses show a shift from NK cells and macrophages to T cells and enhanced immune activation. Although circulating and decidual T cells are phenotypically distinct, they demonstrate significant clonotype sharing. We also report significant diversity within decidual macrophages, the frequency of which positively correlates with pregravid maternal body mass index. Interestingly, the ability of decidual macrophages to respond to bacterial ligands is reduced with pregravid obesity, suggestive of skewing toward immunoregulation as a possible mechanism to safeguard the fetus against excessive maternal inflammation. These findings are a resource for future studies investigating pathological conditions that compromise fetal health and reproductive success.

Maternal obesity blunts antimicrobial responses in fetal monocytes

Maternal pre-pregnancy (pregravid) obesity is associated with adverse outcomes for both mother and offspring. Amongst the complications for the offspring is increased susceptibility and severity of neonatal infections necessitating admission to the intensive care unit, notably bacterial sepsis and enterocolitis. Previous studies have reported aberrant responses to LPS and polyclonal stimulation by umbilical cord blood monocytes that were mediated by alterations in the epigenome. In this study, we show that pregravid obesity dysregulates umbilical cord blood monocyte responses to bacterial and viral pathogens. Specifically, interferon-stimulated gene expression and inflammatory responses to respiratory syncytial virus (RSV) and E. coli were significantly dampened, respectively . Although upstream signaling events were comparable, translocation of the key transcription factor NF-κB and chromatin accessibility at pro-inflammatory gene promoters following TLR stimulation was significantly attenuated. Using a rhesus macaque model of western style diet-induced obesity, we further demonstrate that this defect is detected in fetal peripheral monocytes and tissue-resident macrophages during gestation. Collectively, these data indicate that maternal obesity alters metabolic, signaling, and epigenetic profiles of fetal monocytes leading to a state of immune paralysis during late gestation and at birth.

Maternal Western-style diet remodels the transcriptional landscape of fetal hematopoietic stem and progenitor cells in rhesus macaques

Maternal obesity adversely impacts the in utero metabolic environment, but its effect on fetal hematopoiesis remains incompletely understood. During late development, the fetal bone marrow (FBM) becomes the major site where macrophages and B lymphocytes are produced via differentiation of hematopoietic stem and progenitor cells (HSPCs). Here, we analyzed the transcriptional landscape of FBM HSPCs at single-cell resolution in fetal macaques exposed to a maternal high-fat Western-style diet (WSD) or a low-fat control diet. We demonstrate that maternal WSD induces a proinflammatory response in FBM HSPCs and fetal macrophages. In addition, maternal WSD consumption suppresses the expression of B cell development genes and decreases the frequency of FBM B cells. Finally, maternal WSD leads to poor engraftment of fetal HSPCs in nonlethally irradiated immunodeficient NOD/SCID/IL2rγ^-/- mice. Collectively, these data demonstrate for the first time that maternal WSD impairs fetal HSPC differentiation and function in a translationally relevant nonhuman primate model.

Increasing Pre-pregnancy Body Mass Index and Pregnancy Outcomes in the United States

INTRODUCTION

 As many Americans are becoming overweight or obese, increased body mass index (BMI) is fast becoming normalized. There is a need for more research that highlights the association between pre-pregnancy obesity and adverse pregnancy outcomes.

AIM

To determine the association between increasing pre-pregnancy BMI and adverse pregnancy outcomes.

METHODS

We utilized the United States Vital Statistics records to collate data on all childbirths in the United States between 2015 and 2019. We determined the association between increasing pre-pregnancy BMI and adverse pregnancy outcomes using multivariate analysis. Neonatal outcomes measures include the five-minute Apgar score, neonatal unit admission, neonates receiving assisted ventilation > six hours, neonatal antibiotics use, and neonatal seizures. Maternal outcomes include cesarean section rate, mothers requiring blood transfusion, unplanned hysterectomy, and intensive care unit admission. In addition, we controlled for maternal parameters such as race/ethnicity, age, insurance type, and pre-existing conditions such as chronic hypertension and prediabetes. Other covariates include paternal race, age and education level, gestational diabetes mellitus, induction of labor, weight gain during pregnancy, gestational age at delivery, and delivery weight.

RESULTS

We studied 15,627,572 deliveries in the US Vital Statistics records between 2015 and 2019. Among these women, 3.36% were underweight, 43.19% were with a normal BMI, 26.34% were overweight, 14.73% were in the obese class I, 7.23% were in the obese class II, and 5.14% were in the obese class III. Increasing pre-pregnancy BMI was associated with significant adverse outcomes across all measures of maternal and neonatal outcomes.

CONCLUSION

 A strong association exists between increasing pre-pregnancy BMI and adverse maternal and neonatal outcomes. The higher risk of adverse pregnancy outcomes among overweight and obese women remained even after controlling for other traditional risk factors of adverse maternal and neonatal outcomes.

Association between pre-pregnancy body mass index and gestational weight gain on pregnancy outcomes: a cohort study in Indonesian pregnant women

Background

Pre-pregnancy BMI (PP BMI) and gestational weight gain (GWG) are prominent anthropometric indicators for maternal nutritional status and are related to an increased risk of adverse pregnancy outcomes. This study aimed to determine the factors affecting total GWG, PP BMI and pregnancy outcomes among pregnant women in West Sumatra, Indonesia.

Methods

This observational analysis was conducted among healthy women in the Vitamin D Pregnant Mother (VDPM) cohort study. A total of 195 pregnant women and their newborn babies were enrolled, and information regarding their socio-demographic characteristics, obstetric history, dietary intake and anthropometric data were assessed through direct interviews. Furthermore, the Institute of Medicine (IOM) 2009 guidelines were used to obtain the total GWG.

Results

PP BMI was used to categorise the 195 pregnant women as overweight/obese (43.1%), normal (46.7%) and underweight (10.2%). There were 53.3%, 34.4% and 12.3% of women who had inadequate, adequate and excessive GWG, respectively. The multinomial logistic regression model indicated that overweight or obese women at the pre-pregnancy stage were 4.09 times more likely to have an excessive rate of GWG (AOR = 4.09, 95% CI: 1.38–12.12, p = 0.011) than those whose weight was normal. Furthermore, women with excessive GWG were 27.11 times more likely to have a baby with macrosomia (AOR = 27.11, 95% CI: 2.99–245.14) (p = 0.001) and those with inadequate GWG were 9.6 times more likely to give birth to a baby with low birth weight (LBW) (AOR = 9.60, 95% CI; 0.88–105.2) (p = 0.002).

Conclusions

This study demonstrates that the malnutrition status prior to pregnancy and inadequate or excessive GWG status during pregnancy as significant risk factors for developing adverse pregnancy outcomes. These findings highlight the importance of providing information, preconception counselling and health education on weight management for healthy pregnancies.

Supplementary information

The online version contains supplementary material available at 10.1186/s12884-022-04815-8.

The Epidemiology and Mechanisms of Lifetime Cardiopulmonary Morbidities Associated With Pre-Pregnancy Obesity and Excessive Gestational Weight Gain

Obesity has reached pandemic proportions in the last few decades. The global increase in obesity has contributed to an increase in the number of pregnant women with pre-pregnancy obesity or with excessive gestational weight gain. Obesity during pregnancy is associated with higher incidence of maternal co-morbidities such as gestational diabetes and hypertension. Both obesity during pregnancy and its associated complications are not only associated with immediate adverse outcomes for the mother and their newborns during the perinatal period but, more importantly, are linked with long-term morbidities in the offsprings. Neonates born to women with obesity are at higher risk for cardiac complications including cardiac malformations, and non-structural cardiac issues such as changes in the microvasculature, e.g., elevated systolic blood pressure, and overt systemic hypertension. Pulmonary diseases associated with maternal obesity include respiratory distress syndrome, asthma during childhood and adolescence, and adulthood diseases, such as chronic obstructive pulmonary disease. Sequelae of short-term complications compound long-term outcomes such as long-term obesity, hypertension later in life, and metabolic complications including insulin resistance and dyslipidemia. Multiple mechanisms have been proposed to explain these adverse outcomes and are related to the emerging knowledge of pathophysiology of obesity in adults. The best investigated ones include the role of obesity-mediated metabolic alterations and systemic inflammation. There is emerging evidence linking metabolic and immune derangements to altered biome, and alteration in epigenetics as one of the intermediary mechanisms underlying the adverse outcomes. These are initiated as part of fetal adaptation to obesity during pregnancy which are compounded by rapid weight gain during infancy and early childhood, a known complication of obesity during pregnancy. This newer evidence points toward the role of specific nutrients and changes in biome that may potentially modify the adverse outcomes observed in the offsprings of women with obesity.

Group B streptococcal infection of the genitourinary tract in pregnant and non-pregnant patients with diabetes mellitus: An immunocompromised host or something more?

Group B Streptococcus (GBS), also known as Streptococcus agalactiae is a Gram-positive bacterium commonly encountered as part of the microbiota within the human gastrointestinal tract. A common cause of infections during pregnancy, GBS is responsible for invasive diseases ranging from urinary tract infections to chorioamnionitis and neonatal sepsis. Diabetes mellitus (DM) is a chronic disease resulting from impaired regulation of blood glucose levels. The incidence of DM has steadily increased worldwide to affecting over 450 million people. Poorly controlled DM is associated with multiple health comorbidities including an increased risk for infection. Epidemiologic studies have clearly demonstrated that DM correlates with an increased risk for invasive GBS infections, including skin and soft tissue infections and sepsis in non-pregnant adults. However, the impact of DM on risk for invasive GBS urogenital infections, particularly during the already vulnerable time of pregnancy, is less clear. We review the evolving epidemiology, immunology, and pathophysiology of GBS urogenital infections including rectovaginal colonization during pregnancy, neonatal infections of infants exposed to DM in utero, and urinary tract infections in pregnant and non-pregnant adults in the context of DM and highlight in vitro studies examining why DM might increase risk for GBS urogenital infection.

Associations between maternal obesity and infectious morbidity in Zimbabwean infants

The prevalence of overweight and obesity is increasing among reproductive-age women in sub-Saharan Africa. Whether maternal body mass index (BMI) influences the risk of infant infections in low- and middle-income countries (LMIC) is uncertain. We used data from a birth cohort of 5344 HIV-unexposed Zimbabwean infants with available data on maternal BMI, to calculate rates of sick clinic visits for infections during the first 12 months postpartum, and adjusted hazard ratios (aHR) for each maternal BMI group. Compared to infants of mothers with normal BMI, the rate of sick clinic visits for any infection progressively rose among infants of overweight (aHR 1.05; 95%CI 0.99, 1.11) and obese women (aHR 1.15; 95%CI 1.05, 1.25). Excess clinic attendances were particularly due to skin, respiratory and ear infections. Maternal obesity may therefore influence infant infectious morbidity in LMIC over the first year after birth.

Phenotypic and Epigenetic Adaptations of Cord Blood CD4+ T Cells to Maternal Obesity

Pregravid obesity has been shown to disrupt the development of the offspring's immune system and increase susceptibility to infection. While the mechanisms underlying the impact of maternal obesity on fetal myeloid cells are emerging, the consequences for T cells remain poorly defined. In this study, we collected umbilical cord blood samples from infants born to lean mothers and mothers with obesity and profiled CD4 T cells using flow cytometry and single cell RNA sequencing at resting and following ex vivo polyclonal stimulation. We report that maternal obesity is associated with higher frequencies of memory CD4 T cells suggestive of in vivo activation. Moreover, single cell RNA sequencing revealed expansion of an activated subset of memory T cells with maternal obesity. However, ex vivo stimulation of purified CD4 T cells resulted in poor cytokine responses, suggesting functional defects. These phenotypic and functional aberrations correlated with methylation and chromatin accessibility changes in loci associated with lymphocyte activation and T cell receptor signaling, suggesting a possible link between maternal obesogenic environment and fetal immune reprogramming. These observations offer a potential explanation for the increased susceptibility to microbial infection in babies born to mothers with obesity.

Obesity, Second Stage Duration, and Labor Outcomes in Nulliparous Women

OBJECTIVE

This study aimed to estimate second stage duration and its effects on labor outcomes in obese versus nonobese nulliparous women.

STUDY DESIGN

This was a secondary analysis of a cohort of nulliparous women who presented for labor at term and reached complete cervical dilation. Adjusted relative risks (aRR) were used to estimate the association between obesity and second stage characteristics, composite neonatal morbidity, and composite maternal morbidity. Effect modification of prolonged second stage on the association between obesity and morbidity was assessed by including an interaction term in the regression model.

RESULTS

Compared with nonobese, obese women were more likely to have a prolonged second stage (aRR: 1.48, 95% CI: 1.18-1.85 for ≥3 hours; aRR: 1.65, 95% CI: 1.18-2.30 for ≥4 hours). Obesity was associated with a higher rate of second stage cesarean (aRR: 1.78, 95% CI: 1.34-2.34) and cesarean delivery for fetal distress (aRR: 2.67, 95% CI: 1.18-3.58). Obesity was also associated with increased rates of neonatal (aRR: 1.38, 95% CI: 1.05-1.80), but not maternal morbidity (aRR: 1.06, 95% CI: 0.90-1.25). Neonatal morbidity risk was not modified by prolonged second stage.

CONCLUSION

Obesity is associated with increased risk of neonatal morbidity, which is not modified by prolonged second stage of labor.

The Influence of Obesity and Associated Fatty Acids on Placental Inflammation

PURPOSE

Maternal obesity, affecting nearly 1 in 4 pregnancies, is associated with increased circulating saturated fatty acids, such as palmitate. These fatty acids are implicated in placental inflammation, which may in turn exacerbate both maternal-fetal tolerance and responses to pathogens, such as group B Streptococcus. In this review, we address the question, "How do obesity and associated fatty acids influence placental inflammation?"

METHODS

In this narrative review, we searched PubMed and Google Scholar using combinations of the key words placental inflammation or pregnancy and lipids, fatty acids, obesity, palmitate, or other closely related search terms. We also used references found within these articles that may have been absent from our original search queries. We analyzed methods and key results of these articles to compare and contrast their findings, which were occasionally at odds with each other.

FINDINGS

Although obesity can be studied as a whole, complex phenomena with in vivo mouse models and human samples from patients with obesity, in vitro modeling often relies on the treatment of cells or tissues with ≥1 fatty acids and occasionally other compounds (eg, glucose and insulin). We found that palmitate, most commonly used in vitro to recreate hallmarks of obesity, induces apoptosis, oxidative stress, mitochondrial dysfunction, autophagy defects, and inflammasome activation in many placental cell types. We compare this to in vivo models of obesity wherever possible. We found that obesity as a whole may have more complex regulation of these phenomena (apoptosis, oxidative stress, mitochondrial dysfunction, autophagy defects, and inflammasome activation) compared with in vitro models of fatty acid treatment (primarily palmitate) because of the presence of unsaturated fatty acids (ie, oleate), which may have anti-inflammatory effects.

IMPLICATIONS

The interaction of unsaturated fatty acids with saturated fatty acids may ameliorate many inflammatory effects of saturated fatty acids alone, which complicates interpretation of in vitro studies that focus on a particular fatty acid in isolation. This complication may explain why certain studies of obesity in vivo have differing outcomes from studies of specific fatty acids in vitro.

Maternal BMI at the time of birth and selected risk factors associated with severe neonatal outcomes: a secondary analysis of the WHO Better Outcomes in Labour Difficulty (BOLD) project

The main objective of this secondary analysis was to describe the nutritional status of the Better Outcomes in Labour Difficulty (BOLD) project study population and determine possible associations between maternal nutritional status (as reflected by maternal BMI at the time of birth) and severe neonatal outcomes (SNO). We also analysed previous and index maternal pathologies to determine associations with neonatal outcomes. We used the classification designed by Atalah for maternal BMI and compared with the Hyperglycaemia and Adverse Pregnancy Outcome study one. To describe the nutritional status of this population, figures of distribution and test of normality related to weight and BMI were presented for the women and their babies. To explore the association between maternal BMI data and SNO, the χ2 test was performed. To identify a maternal characteristic or a group of characteristics that could predict SNO, we used Fisher's exact test using previous maternal pathology collected in the BOLD project as well as that in the index pregnancy. In this study, BMI at the time of birth was not associated with neonatal near miss or death. We found that previous maternal obesity, diabetes and chronic hypertension were associated with SNO. Maternal pathology in the index pregnancy such as other obstetric haemorrhage, pre-eclampsia, anaemia and gestational diabetes was associated with SNO.

Impact of pregravid obesity on maternal and fetal immunity: Fertile grounds for reprogramming

Maternal pregravid obesity results in several adverse health outcomes during pregnancy, including increased risk of gestational diabetes, preeclampsia, placental abruption, and complications at delivery. Additionally, pregravid obesity and in utero exposure to high fat diet have been shown to have detrimental effects on fetal programming, predisposing the offspring to adverse cardiometabolic, endocrine, and neurodevelopmental outcomes. More recently, a deeper appreciation for the modulation of offspring immunity and infectious disease-related outcomes by maternal pregravid obesity has emerged. This review will describe currently available animal models for studying the impact of maternal pregravid obesity on fetal immunity and review the data from clinical and animal model studies. We also examine the burden of pregravid obesity on the maternal-fetal interface and the link between placental and systemic inflammation. Finally, we discuss future studies needed to identify key mechanistic underpinnings that link maternal inflammatory changes and fetal cellular reprogramming events.

Chitotriosidase Levels in the Colostrum from Mothers of Term and Preterm Infants

Background: Breast milk Chitotriosidase (Chit 1) shows antifungal effect and has an active role in the natural immune response against certain pathogens. The aim of this study was to compare colostrum Chit 1 levels from mothers of term and preterm infants. Materials and Methods: The study included 72 mothers of 32 preterm and 40 term infants (gestational age; 33.7 ± 1.8 vs. 39.1 ± 1.1 weeks, birth weight; 1931.7 ± 539.8 vs. 3350.9 ± 419.7 g). Breast milk samples were taken at postnatal 24-48 hours. Chit 1 level was evaluated with the quantitative calorimetric method. Results: No significant difference was determined between the term and preterm groups in terms of maternal age, education level, weight gain in pregnancy, and body mass index (BMI). The median colostrum Chit 1 level was higher in the preterm group, but the difference was not statistically significant between two groups (p = 0.43). There is no association between colostrum Chit 1 level, maternal age, gravida, BMI, infant gender, income level, and pre-eclampsia. The colostrum Chit 1 level of mothers who had weight gain exceeding the recommended limits was significantly lower than mothers with weight gain within the recommended limits in the term group (4346.2 vs. 4914.2, p = 0.021). A negative correlation was determined between the birthweight of term infants and the colostrum Chit 1 levels (p = 0.045, r = -0.319). Conclusion: Although the data need to be validated by further investigation, the observations made in this study seem to indicate that colostrum Chit-1 may have role in the protection of preterm infants.

Neonatal Morbidity in the Offspring of Obese Women Without Hypertension or Diabetes

OBJECTIVE

To compare the independent risk of neonatal morbidity between the offspring of obese and nonobese women without hypertension or diabetes.

METHODS

This is a secondary analysis of a prospective single-center cohort study of singleton deliveries at or beyond 37 weeks of gestation from 2010 to 2014. Women with diabetes (pregestational or gestational) and hypertensive disorders were excluded. The primary outcomes were 1) a composite neonatal morbidity including death, mechanical ventilation, respiratory distress, meconium aspiration, suspected sepsis, confirmed sepsis, hypoxic-ischemic encephalopathy, therapeutic hypothermia, or seizures; and 2) a composite of neonatal neurologic morbidity including hypoxic-ischemic encephalopathy, therapeutic hypothermia, or seizures. The primary outcomes were compared between the offspring of obese (body mass index 30 or greater) and nonobese women. Adjusted odds ratios (ORs) were estimated using multivariable logistic regression.

RESULTS

Of 6,458 women without diabetes or hypertensive disorders, 3,311 (51%) were obese. After adjusting for race, neonates of obese patients were at significantly increased risk for the composite neonatal morbidity (9.2% vs 7.2%, adjusted OR 1.39, 95% CI 1.15-1.67) and neurologic neonatal morbidity (0.7% vs 0.3%, adjusted OR 2.84, 95% CI 1.22-6.65). Specifically, neonates of obese patients were more likely to have hypoxic-ischemic encephalopathy (0.5% vs 0.2%, adjusted OR 2.80, 95% CI 1.02-7.68), hypothermia treatment (0.6% vs 0.2%, adjusted OR 2.92 95% CI 1.17-7.30), and suspected sepsis (7.6% vs 5.8%, adjusted OR 1.45, 95% CI 1.18-1.79).

CONCLUSION

In patients who labor, maternal obesity is an independent risk factor for significant neonatal morbidity, even in the absence of hypertensive disorders or diabetes.

Inflammatory Determinants of Pregravid Obesity in Placenta and Peripheral Blood

Pre-pregnancy (pregravid) obesity has been linked to several adverse health outcomes for both mother and offspring. Complications during pregnancy include increased risk for gestational diabetes, hypertension, preeclampsia, placental abruption, and difficulties during delivery. Several studies suggest that these negative outcomes are mediated by heightened systemic inflammation as well as changes in placental development and function. However, the molecular mechanisms by which pregravid obesity affects these processes are poorly understood. In this study, we aimed to address this question by carrying out a comprehensive analysis of the systemic maternal immune system coupled with placental gene expression and microbial profiling at term delivery (11 lean and 14 obese). Specifically, we examined the impact of pregravid obesity on circulating cytokines, chemokine, adipokines, and growth factors using multiplex Luminex assay. Innate and adaptive immune cell frequencies and their cytokine production in response to stimuli were measured using flow cytometry. Finally, changes in placental transcriptome and microbiome were profiled using RNA- and 16S-sequencing, respectively. Pregravid obesity is characterized by insulin and leptin resistance, high levels of circulating inflammatory markers IL-6 and CRP, in addition to chemokine IL-8 (p < 0.01). Moreover, pregravid obesity was associated with lower frequency of naïve CD4+ T-cells (p < 0.05), increased frequency of memory CD4+ T-cells (p < 0.01), and a shift towards Th2 cytokine production (p = 0.05). Myeloid cells from the obese cohort produced higher levels of pro-inflammatory cytokines but lower levels of chemokines following TLR stimulation (p < 0.05). Lastly, pregravid obesity is associated with increased abundance of Bacteroides and changes in the expression of genes important for nutrient transport and immunity (FDR < 0.05). Collectively, these data indicate that pregravid obesity is associated with heightened systemic inflammation and of dysregulated nutrient transport in the placenta and provide insight into the basis of fetal reprogramming.

Maternal Pregravid Obesity Remodels the DNA Methylation Landscape of Cord Blood Monocytes Disrupting Their Inflammatory Program

Prepregnancy maternal obesity is associated with adverse outcomes for the offspring, including increased incidence of neonatal bacterial sepsis and necrotizing enterocolitis. We recently reported that umbilical cord blood (UCB) monocytes from babies born to obese mothers generate a reduced IL-6/TNF-α response to TLR 1/2 and 4 ligands compared to those collected from lean mothers. These observations suggest altered development of the offspring's immune system, which in turn results in dysregulated function. We therefore investigated transcriptional and epigenetic differences within UCB monocytes stratified by prepregnancy maternal body mass index. We show that UCB monocytes from babies born to obese mothers generate a dampened response to LPS stimulation compared with those born to lean mothers, at the level of secreted immune mediators and transcription. Because gene expression profiles of resting UCB monocytes from both groups were comparable, we next investigated the role of epigenetic differences. Indeed, we detected stark differences in methylation levels within promoters and regulatory regions of genes involved in TLR signaling in resting UCB monocytes. Interestingly, the DNA methylation status of resting cells was highly predictive of transcriptional changes post-LPS stimulation, suggesting that cytosine methylation is one of the dominant mechanisms driving functional inadequacy in UCB monocytes obtained from babies born to obese mothers. These data highlight a potentially critical role of maternal pregravid obesity-associated epigenetic changes in influencing the function of an offspring's monocytes at birth. These findings further our understanding of mechanisms that explain the increased risk of infection in neonates born to mothers with high prepregnancy body mass index.

Obesity and pregnancy outcomes: Do the relationships differ by maternal region of birth? A retrospective cohort study

BACKGROUND

We aimed to determine whether the association between obesity and a range of adverse maternal and perinatal outcomes differed in South Asian and Australian and New Zealand born women.

METHODS

A retrospective cohort study of singleton births in South Asian (SA) and Australian/New Zealand (AUS/NZ) born women at an Australian hospital between 2009 and 2013. The interaction between maternal region of birth and obesity on a range of maternal and perinatal outcomes was assessed using multivariate logistic regression.

RESULTS

Obesity was more strongly associated with gestational hypertension/Preeclampsia/HELLP and Gestational Diabetes Mellitus in AUS/NZ born women (p = 0.001 and p < 0.001, respectively for interaction) and was only associated with shoulder dystocia in SA born women (p = 0.006 for interaction). There was some evidence that obesity was more strongly related with admission to NICU/Special care nursery (SCN) (p = 0.06 for interaction) and any perinatal morbidity (p = 0.05 for interaction) in SA born women.

CONCLUSIONS

Interventions targeted at reducing maternal obesity will have different impacts in SA compared to AUS/NZ born women.

Clinical and microbiological features of maternal sepsis: a retrospective study

BACKGROUND

Identifying pregnant women with sepsis is challenging because diagnostic clinical and laboratory criteria overlap with normal pregnant physiologic indices. Our primary study aim was to describe clinical and laboratory characteristics of women diagnosed with sepsis, severe sepsis and septic shock. Our secondary aim was to determine positive predictive values for International Classification of Disease (ICD)-9 billing codes for sepsis, severe sepsis, and septic shock.

METHODS

After gaining Institutional Review Board approval, we identified women with ICD-9 codes for sepsis, severe sepsis and septic shock who were admitted to a single tertiary obstetric center from 2007-2013. Diagnoses were confirmed using criteria from the International Sepsis Definitions Conference report. Demographic, obstetric, vital signs and laboratory data were abstracted by medical chart review.

RESULTS

We identified 190 women with sepsis-related ICD-9 codes: of these, 35 (18%) women met the criteria for a clinical diagnosis of sepsis, severe sepsis or septic shock. Twenty (57%) women had a sepsis-related diagnosis after cesarean delivery. Twenty-one (60%) women had one or more pre-existing medical conditions and 19 (54%) women had one or more obstetric-related conditions. The genital tract was the most common site of infection. We observed considerable heterogeneity in maternal vital signs and laboratory indices for women with ICD-9 codes for sepsis, severe sepsis, and septic shock. The positive predictive value for each sepsis-related ICD-9 code was low: 16% (95% CI 10 to 24%) for sepsis, 10% (95% CI 3 to 25%) for severe sepsis and 24% (95% CI 10 to 46%) for septic shock.

CONCLUSION

We identified marked heterogeneity in patient characteristics, clinical features, laboratory indices and microbiological findings among cohorts of women diagnosed with maternal sepsis, severe sepsis or septic shock. Based on our findings, the incidence of maternal sepsis using ICD-9 codes may be significantly overestimated.