Overweight and Obesity before, during and after Pregnancy: Part 1: Pathophysiology, Molecular Biology and Epigenetic Consequences

Interpregnancy weight change and neonatal and infant outcomes: A systematic review and meta-analysis

PURPOSE

To synthesize evidence regarding the association between interpregnancy weight change (IPWC) in consecutive pregnancies and neonatal or infant outcomes in the subsequent pregnancy.

METHODS

Search strategy was implemented in MEDLINE, EMBASE, Web of Science, Scopus and Cochrane Library from their inception to 13 November 2023. The most adjusted odds ratio (OR) or risk ratio estimates provided by original studies were used to calculate pooled risk ratios and their corresponding 95 % confidence intervals (CI) with the DerSimonian and Laird random effects method. Publication bias was assessed by funnel plots and Egger's method, and risk of bias was assessed with The NewcastleOttawa Quality Assessment Scale.

RESULTS

Thirty-seven observational studies were included. Interpregnancy weight loss or gain were associated with large for gestational age (OR: 0.89; 95 % CI: 0.84-0.94; I2 = 83.6 % and OR: 1.33; 95 % CI:1.26-1.40; I2 = 98.9 %), and stillbirth risk (OR: 1.10; 95 % CI: 1.01-1.18; I2 = 0.0 % and OR: 1.21; 95 % CI: 1.09-1.33; I2 = 60.2 %,).

CONCLUSIONS

Findings highlight the importance of managing weight between interpregnancy periods, although these findings should be interpreted cautiously because of the possible influence of social determinants of health and other factors.

Association with pre-pregnancy BMI on early pregnancy loss in infertility patients in first HRT-FET cycles: A retrospective cohort study

OBJECTIVE

To investigate the association between pre-pregnancy body mass index (BMI) and the early pregnancy loss rate in patients in first hormone replacement therapy-frozen-thawed embryo transfer (HRT-FET) cycles and find the threshold.

METHODS

A retrospective cohort study was conducted using a total of 14030 HRT-FET cycles at the Reproductive Center from January 2017 to December 2021. The association of pre-pregnancy BMI on early pregnancy loss rate in patients in HRT-FET cycles was assessed by performing univariate analysis, multivariable logistic regression, curve fitting and threshold effect analysis.

RESULTS

There were 2076 cycles of early pregnancy loss, and the pregnancy loss rate was 14.80%. After adjusting for confounding factors, the early pregnancy loss rate of the obese group was significantly higher than that of the normal weight group (P < 0.05). The threshold effect analysis showed that as the pre-pregnancy BMI ranged from 21.2 to 25.8 kg/m2, the early pregnancy loss rate came to the plateau phase at the low level. In addition, when the BMI was ≥ 25.8 kg/m2, the early pregnancy loss rate increased by 3% (aOR = 1.03, P = 0.01) with each 1 kg/m2 increment of BMI.

CONCLUSION

The early pregnancy loss rate might achieve a low level when the pre-pregnancy BMI was within the range of 21.2- 25.8 kg/m2. The early pregnancy loss rate would increase when pre-pregnancy BMI is more than 25.8 kg/m2. For patients in HRT-FET cycles, adjusting their pre-pregnancy BMI to the optimal level by following a healthy diet and daily exercise may help to reduce the early pregnancy loss.

Multiparity increases the risk of diabetes by impairing the proliferative capacity of pancreatic β cells

Pregnancy imposes a substantial metabolic burden on women, but little is known about whether or how multiple pregnancies increase the risk of maternal postpartum diabetes. In this study, we assessed the metabolic impact of multiple pregnancies in humans and in a rodent model. Mice that underwent multiple pregnancies had increased adiposity, but their glucose tolerance was initially improved compared to those of age-matched virgin mice. Later, however, insulin resistance developed over time, but insulin secretory function and compensatory pancreatic β cell proliferation were impaired in multiparous mice. The β cells of multiparous mice exhibited aging features, including telomere shortening and increased expression of Cdkn2a. Single-cell RNA-seq analysis revealed that the β cells of multiparous mice exhibited upregulation of stress-related pathways and downregulation of cellular respiration- and oxidative phosphorylation-related pathways. In humans, women who delivered more than three times were more obese, and their plasma glucose concentrations were elevated compared to women who had delivered three or fewer times, as assessed at 2 months postpartum. The disposition index, which is a measure of the insulin secretory function of β cells, decreased when women with higher parity gained body weight after delivery. Taken together, our findings indicate that multiple pregnancies induce cellular stress and aging features in β cells, which impair their proliferative capacity to compensate for insulin resistance.

Association of Leptin and Retinol Binding Protein 4 with the Risk of Gestational Diabetes: A Systematic Review and Meta-Analysis of Observational Studies

The positive correlation between serum levels of retinol binding protein 4 (RBP4) and gestational diabetes (GDM) has been proven in the previous meta-analysis on case-control studies. However, its association with serum levels of leptin is not studied in any meta-analysis. Therefore, we performed an updated systematic review of observational studies evaluating the association between serum RBP4 and leptin with the risk of GDM. A systematic search was performed on four databases, including PubMed, Scopus, Web of Science, and Google Scholar, up to March 2021. After screening and deleting duplicates, nine articles met our inclusion criteria. Studies had case-control and cohort design, and included 5074 participants with a mean age range between 18 and 32.65 years (2359 participants for RBP4 and 2715 participants for leptin). Interestingly, this meta-analysis revealed higher levels of RBP4 (OR=2.04; 95% CI: 1.37, 3.04) and leptin (OR=2.32; 95% CI: 1.39, 3.87) are significantly associated with the increased risk of overall GDM. The subgroup analysis approved the results based on the study design, trimester of pregnancy and serum/plasms to investigate the source of heterogeneity. The present meta-analysis determines serum leptin and RBP4 levels as predictors of GDM occurrence. However, studies included in this meta-analysis showed significant heterogeneity.

Dietary Intake Patterns and Lifestyle Behaviors of Pregnant Women Living in a Manitoba First Nations Community: Implications for Fetal Alcohol Spectrum Disorder

The information on the nutrition status of women at-risk of carrying a child with fetal alcohol spectrum disorder (FASD) is scarce, particularly in the First Nations population living on reserve. This study examined and compared nutrition status, dietary intake, and lifestyle patterns of pregnant at-risk, defined as those who consume alcoholic drink during the current pregnancy, and non-at-risk women living in northern Manitoban community. Thirty-seven pregnant, First Nations women (at-risk n = 15; non-at-risk, n = 22) were recruited to participate in the study. A questionnaire, presented in paper and iPad formats, collected information on participants’ demographics, dietary intake, lifestyle, pregnancy outcomes, and maternal health. A food frequency questionnaire and 24-h recall were used to determine nutrient intake. Nutrient values were assessed using Dietary Reference Intakes (DRI). At-risk and non-at-risk women were below the Canada Food Guide serving size recommended for Vegetable and Fruit, Grain, and Milk Products with 93%, 92%, and 93% of participants not meeting the recommendations, respectively. Women met the recommendations for vitamins A, B1, B12, C, niacin, choline, as well as calcium, and zinc. Sixty eight percentage (%) of participants did not meet the recommendations for folate and iron, and 97% for docosahexaenoic acid (DHA). Significant differences were observed between non-at-risk and at-risk women for mean % DRI intakes of vitamin C (313 ± 224 vs. 172 ± 81 mg/day), niacin (281 ± 123 vs. 198 ± 80 mg/day), folate (70 ± 38 vs. 10 ± 22 mcg/day), and iron (101 ± 74 vs. 74 ± 30 mg/day). The findings of this study lay a fundamental premise for the development of community nutrition programs, nutrition education, and nutrition intervention, such as community specific prenatal supplementation. These will assist in ensuring adequate maternal nutrient intake and benefit families and communities in Northern Manitoba with and without alcohol insult.

Gestational obesity: An unconventional endocrine disruptor for the fetus

Obesity has reached pandemic proportions and is a growing concern throughout the world. A parallel trend has also been observed among women in reproductive age, leading to the increasing global prevalence of gestational obesity (GO). The well-known obesity-related health problems also extend to pregnancy, where they are responsible for giving rise to a variety of medical and obstetrical complications, resulting in an increased incidence of adverse maternal and fetal outcomes. In this context, several epidemiological and clinical studies have shown that nutritional changes through different stages of gestation can have a substantial impact on the future health and development of the child. Therefore, it is clear that GO is a modifiable endocrine disruptor that negatively influences the health of the fetus and the newborn, with long-term metabolic implications. This review aims to describe the impact of GO on maternal and fetal outcomes using the available scientific literature and highlighting the evidence-based nutritional approaches currently recommended for the management of GO.

Association between television viewing and overweight and obesity among women of reproductive age in Timor-Leste: evidence from the demographic health survey 2016

OBJECTIVE

This study aimed to assess the possible relationship between television viewing and overweight and obesity among Timorese women of reproductive age.

METHODS

This cross-sectional study analysed the Timor-Leste Demographic and Health Survey 2016 dataset. A weighted sample of 11 398 Timorese women aged 15-49 years was chosen using a two-stage stratified random sampling technique. Asian criteria-based body mass index (BMI) cut-offs were used to define overweight (BMI 23.0 to <27.5 kg/m²) and obesity (BMI ≥27.5 kg/m²). Frequency of TV viewing was categorised into three groups: (1) not at all, (2) less than once a week and (3) at least once a week. Multilevel ordered logistic regression was performed to identify the correlates of overweight and obesity. Both crude and adjusted odds ratios (AOR) along with a 95% CI were calculated to show the strength of association.

RESULTS

Among 11 398 respondents, 19.4% were overweight or obese (overweight: 15.7% and obese: 3.8%). Although about half of the respondents reportedly did not watch TV at all, just over two-thirds watched TV at least once a week. Women who watched TV at least once a week were found to have 1.3 times the odds of being overweight or obese compared with those who never watched TV (AOR: 1.3, 95% CI: 1.1 to 1.5; p<0.001). However, when stratified by settlement type, the statistical significance stood for the rural women only (AOR: 1.5, 95% CI: 1.2 to 1.8; p<0.001), after adjusting for the covariates.

CONCLUSION

Watching TV at least once a week was found to be a significant correlate of overweight and obesity in rural Timorese women of reproductive age. Further studies need to be undertaken to assess physical activity, sedentary and dietary patterns to clarify the possible mechanism through which TV viewing may influence BMI in those groups.

Lifelong prevention of cardiovascular disease. Part I: preconceptional, prenatal and infant periods of life

Current prophylactic actions prevent or significantly delay the majority of cardiovascular diseases (CVD). Various factors are interconnected and affect a person throughout his life, determining the risk of CVD. This indicates the need for preventive measures at all stages of life and even before birth. The beneficial effects of CVD prevention are realized through various genetic, epigenetic and metabolic mechanisms. Due to the fact that many risk factors for CVD have a cumulative effect, the introduction of preventive measures from the earliest life stages will be most effective. The purpose of the article is to consider various aspects of CVD prevention in the preconceptional, prenatal and infant periods.

Changes in Maternal Body Mass Index, Weight Gain and Outcome of Singleton Pregnancies from 2000 to 2015: A Population-based Retrospective Cohort Study in Hesse/Germany

Introduction Maternal obesity and excessive gestational weight gain (GWG) affect the outcomes of women and their offspring. Our aim was to evaluate population-based data from Germany.

Material and Methods Data from 583 633/791 514 mother-child pairs obtained from the perinatal database in Hesse for the period from 2000 to 2015 were used after excluding incomplete or non-plausible datasets. Early-stage pregnancy maternal body mass index (BMI) and GWG were evaluated. Significant outcome changes were calculated using linear or logistic regression models.

Results The mean maternal age increased from 29.9 to 31.28 years; GWG increased from 445.1 to 457.2 g/week (p < 0.01). Similarly, rates for both overweight and obesity rose from 31.5 to 37.5% (p < 0.001). Cesarean section rates rose from 22.8 to 33.2% (p < 0.001) and rates of postpartum hemorrhage increased from 0.6 to 1% (p < 0.001). There was no significant change in the rates for stillbirth or perinatal mortality (p = 0.92 and p = 0.53 respectively), but there was an increase in the rates of admissions to neonatal intensive care units from 7.8 to 9.5% (p < 0.0001). The percentage of newborns with an Apgar score of < 7 at 5 minutes increased from 1 to 1.1% (p < 0.01) and the rate of neonates with an umbilical artery pH of < 7.1 rose from 1.7 to 2.4% (p < 0.01).

Conclusions In just 15 years, pre-pregnancy BMI and GWG rates of women with singleton pregnancies have increased, and this increase has been accompanied by a significant rise in the rate of cesarean sections and a significant worsening of short-term maternal and neonatal outcomes. It is time to discuss the risks and the short-term and more worrying long-term consequences for mothers and their offspring and the future impact on our healthcare system.

Leptin gene polymorphism (rs7799039; G2548A) is associated with changes in serum lipid concentrations during pregnancy: a prospective cohort study

PURPOSE

Little is known about the effects of leptin and leptin receptor polymorphisms on lipid changes during pregnancy. The aims of this study were to evaluate the associations between the single nucleotide polymorphisms (SNPs) of leptin and leptin receptor genes and the lipid concentrations during pregnancy; and to test whether dietary intake is a mediator in these associations.

METHODS

A prospective cohort of 154 pregnant women was followed up in Rio de Janeiro, Brazil during the following gestational periods: 5-13th, 20-26th and 30-36th weeks. HDL-C, total cholesterol (TC) and triglyceride (TG) were measured by the enzymatic colorimetric method, and LDL-C was calculated. DNA was extracted by the phenol-chloroform method, and leptin (G2548A, rs7799039) and leptin receptor SNPs (Q223R; rs1137101 and K109R; rs1137100) were genotyped using real-time PCR. Statistical analyses included linear mixed-effect models.

RESULTS

Women with the AA genotype of G2548A polymorphism reported a higher fat and total energy intake and had a higher increase in TG concentration during pregnancy than women with AG or GG genotype. The association between G2548A SNP and TG concentrations was not attenuated by adjusting for total lipid (g) and energy (kcal) intake. We did not observe significant associations between the Q223R and K109R SNPs and the lipid concentrations.

CONCLUSIONS

Women homozygous for the A allele of the leptin SNP (G2548A) had a higher increase in TG concentrations per gestational week compared with women with the AG or GG genotype. This is an exploratory and hypothesis-generating study, and the results need confirmation in studies with larger sample sizes.'

Association of polymorphisms in STRA6 gene with gestational diabetes mellitus in a Chinese Han population

Cell and animal experiments have found that in addition to being a retinol transporter, Stimulated by Retinoic Acid 6 (STRA6) also functions as a surface signaling receptor by which retinol regulates insulin responses. Several studies revealed that the STRA6 gene may contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). Gestational diabetes mellitus (GDM) and T2DM have some risk factors in common. The present study was directed to investigate whether the 3 single nucleotide polymorphism (SNPs) (rs11633768, rs351219, and rs736118) of STRA6 correlate with the development of GDM in Chinese pregnant women. We also aimed to estimate the relationship between SNPs with fasting blood glucose level, 1-hour and 2-hour blood glucose levels after 75 g oral glucose intake, fasting insulin and insulin resistance levels to better study the relationship between STRA6 and glucose metabolism.Case-control studies were conducted to compare the GDM and control groups. A total of 334 cases and 367 controls were recruited. Three tagSNPs of STRA6, rs11633768, rs351219, and rs736118, were selected. A chi-square test, logistic regression, and linear regression were used to estimate the relationship between SNPs with GDM risk and oral glucose tolerance test (OGTT), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels. Regression analyses were all adjusted by maternal age, pre-pregnancy BMI, and weekly BMI growth. The Bonferroni correction was applied for multiple comparisons.After adjusting the maternal age, pre-pregnancy BMI and weekly BMI growth, STRA6 rs736118 was associated with fasting insulin level (Beta = -1.468, P = .036), and the association between rs736118 and HOMA-IR was of borderline significance (Beta = -0.290, P = .093) under the dominance model.This study found that there is a significant association between STRA6 polymorphism and GDM.

Replication of previous genome-wide association studies of HKDC1, BACE2, SLC16A11 and TMEM163 SNPs in a gestational diabetes mellitus case-control sample from Han Chinese population

Background: Four novel glucose metabolism risk loci (HKDC1 rs4746822, BACE2 rs6517656, SLC16A11 rs13342232 and TMEM163 rs998451) were identified in recent genome-wide association studies (GWAS) of Afro-Caribbean, European, Hispanic, Thai, Mexican, Latin American and Indian populations. None of the abovementioned SNPs has been reported in a Han Chinese population. Aim: To replicate the relationships between HKDC1 rs4746822, BACE2 rs6517656, SLC16A11 rs13342232 and TMEM163 rs998451 with gestational diabetes mellitus (GDM) in a Han Chinese population. Methods: This was a case-control study which enrolled 334 pregnant women with GDM and 367 pregnant women with normal glucose tolerance. The linear regression and logistic regression were used to estimate the association between SNPs with the risk of GDM, HOMA-IR and fasting insulin levels. The fasting insulin concentration and HOMA-IR were log10 transformed before analysis. Results: No significant differences in the alleles and genotypes of SLC16A11 rs13342232, HKDC1 rs4746822 and BACE2 rs6517656 were observed between cases and controls. After adjusting the weekly BMI growth, pre-pregnancy BMI and maternal age, under the additive model, SLC16A11 rs13342232 was associated with log₁₀fasting serum insulin (Beta=0.046, p=0.016), log₁₀HOMA-IR level (Beta=0.061, p=0.003) and fasting plasma glucose level (Beta=0.164, p=0.011); HKDC1 rs4746822 was associated with OGTT 2-hr plasma glucose level (Beta=0.239, p=0.016); and BACE2 rs6517656 was associated with log₁₀fasting serum insulin (Beta=-0.053, p=0.044) and log₁₀HOMA-IR level (Beta=-0.060, p=0.048). After correction for multiple testing, the associations of SLC16A11 and HKDC1 with glucose metabolism remained statistically significant. The A allele of TMEM163 rs998451 was not detected in this population. Conclusion: HKDC1 rs4746822, BACE2 rs6517656 and SLC16A11 rs13342232 are associated with glucose metabolism in pregnant women of Han Chinese.

Antepartum Care of Women Who Are Obese During Pregnancy: Systematic Review of the Current Evidence

INTRODUCTION

Nearly 40% of US women of childbearing age are obese. Obesity during pregnancy is associated with multiple risks for both the woman and fetus, yet clinicians often feel unprepared to provide optimal antepartum care for this group of women. We collected and reviewed current evidence concerning antepartum care of women who are obese during pregnancy.

METHODS

We conducted a systematic review using PRISMA guidelines. Current evidence relating to the pregnancy care of women with a prepregnancy body mass index of 30kg/m2 or higher was identified using MEDLINE databases via PubMed, Embase, and Web of Science Core Collection between January 2012 and February 2018.

RESULTS

A total of 354 records were located after database searches, of which 63 met inclusion criteria. Topic areas for of included studies were: pregnancy risk and outcomes related to obesity, communication between women and health care providers, gestational weight gain and activity/diet, diabetic disorders, hypertensive disorders, obstructive sleep apnea, mental health, pregnancy imaging and measurement, late antepartum care, and preparation for labor and birth.

DISCUSSION

Midwives and other health care providers can provide better antepartum care to women who are obese during pregnancy by incorporating evidence from the most current clinical investigations.

A qualitative study exploring midwives' perceptions and knowledge of maternal obesity: Reflecting on their experiences of providing healthy eating and weight management advice to pregnant women

Midwives are responsible for providing advice regarding the complex issues of healthy eating and weight management during pregnancy. This study utilised an inductive data-driven thematic approach in order to determine midwives' perceptions, knowledge, and experiences of providing healthy eating and weight management advice to pregnant women. Semistructured interviews with 17 midwives were transcribed verbatim and data subjected to thematic analysis. The findings offer insight into the challenges facing midwives in their role trying to promote healthy eating and appropriate weight management to pregnant women. Three core themes were identified: (a) "If they eat healthily it will bring their weight down": Midwives Misunderstood; (b) "I don't think we are experienced enough": Midwives Lack Resources and Expertise; and (c) "BMI of 32 wouldn't bother me": Midwives Normalised Obesity. The midwives recognised the importance of providing healthy eating advice to pregnant women and the health risks associated with poor diet and obesity. However, they reported the normalisation of obesity in pregnant women and suggested that this, together with their high workload and lack of expertise, explained the reasons why systematic advice was not in standard antenatal care. In addition, the current lack of UK clinical guidance, and thus, possibly lack of clinical leadership are also preventing delivery of tailored advice. Implementation literature on understanding the barriers to optimal health care delivery and informing clinical practice through research evidence needs to be further investigated in this field. This study has recommendations for policy makers, commissioners, service providers, and midwives.

Increasing prevalence of overweight and obesity in Bangladeshi women of reproductive age: Findings from 2004 to 2014

Background

Overweight and obesity are a particular concern for women of reproductive age. They not only increase the risk of chronic diseases but they are also associated with adverse perinatal, neonatal, infant and child outcomes. The objective of this study was to examine the trend of overweight and obesity among Bangladeshi women of reproductive age between 2004 and 2014.

Method

This is a secondary data analysis of the 2004, 2007, 2011 and 2014 Bangladesh Demographic and Health Surveys (BDHS). We determined the age standardized prevalence of overweight and obesity of women aged 15–49 years, who had their weight and height measured. Overweight and obesity were determined using the Asian specific BMI cut-offs criteria.

Result

The prevalence of overweight increased from 11.4% [95% CI: 10.4to 12.5] in 2004 to 25.2% [95% CI: 24.0 to 26.4] in 2014. The prevalence of obesity increased from 3.5% [95% CI: 3.0to4.2] to 11.2% [95% CI: 10.1to12.5%] over the same period of time. This was seen in all age groups. However, the greatest increase was observed in women aged 35 to 49 years. The highest prevalence of overweight and obesity were observed in those women with the highest education level and wealth, larger family size, living in urban areas and not being in paid employment.

Conclusion

The prevalence of overweight and obesity among women of reproductive age in Bangladesh is high and increasing. We speculate that this has the potential to jeopardize the improvements that have been made in maternal and infant health over the last two decades. Evidence based prevention strategies are required to address this serious public health issue.

Pregnancy: An Underutilized Window of Opportunity to Improve Long-term Maternal and Infant Health-An Appeal for Continuous Family Care and Interdisciplinary Communication

Physiologic adaptations during pregnancy unmask a woman's predisposition to diseases. Complications are increasingly predicted by first-trimester algorithms, amplify a pre-existing maternal phenotype and accelerate risks for chronic diseases in the offspring up to adulthood (Barker hypothesis). Recent evidence suggests that vice versa, pregnancy diseases also indicate maternal and even grandparent's risks for chronic diseases (reverse Barker hypothesis). Pub-Med and Embase were reviewed for Mesh terms "fetal programming" and "pregnancy complications combined with maternal disease" until January 2017. Studies linking pregnancy complications to future cardiovascular, metabolic, and thrombotic risks for mother and offspring were reviewed. Women with a history of miscarriage, fetal growth restriction, preeclampsia, preterm delivery, obesity, excessive gestational weight gain, gestational diabetes, subfertility, and thrombophilia more frequently demonstrate with echocardiographic abnormalities, higher fasting insulin, deviating lipids or clotting factors and show defective endothelial function. Thrombophilia hints to thrombotic risks in later life. Pregnancy abnormalities correlate with future cardiovascular and metabolic complications and earlier mortality. Conversely, women with a normal pregnancy have lower rates of subsequent diseases than the general female population creating the term: "Pregnancy as a window for future health." Although the placenta works as a gatekeeper, many pregnancy complications may lead to sickness and earlier death in later life when the child becomes an adult. The epigenetic mechanisms and the mismatch between pre- and postnatal life have created the term "fetal origin of adult disease." Up to now, the impact of cardiovascular, metabolic, or thrombotic risk profiles has been investigated separately for mother and child. In this manuscript, we strive to illustrate the consequences for both, fetus and mother within a cohesive perspective and thus try to demonstrate the complex interrelationship of genetics and epigenetics for long-term health of societies and future generations. Maternal-fetal medicine specialists should have a key role in the prevention of non-communicable diseases by implementing a framework for patient consultation and interdisciplinary networks. Health-care providers and policy makers should increasingly invest in a stratified primary prevention and follow-up to reduce the increasing number of manifest cardiovascular and metabolic diseases and to prevent waste of health-care resources.

Epigenetic Matters: The Link between Early Nutrition, Microbiome, and Long-term Health Development

Epigenetic modifications are among the most important mechanisms by which environmental factors can influence early cellular differentiation and create new phenotypic traits during pregnancy and within the neonatal period without altering the deoxyribonucleic acid sequence. A number of antenatal and postnatal factors, such as maternal and neonatal nutrition, pollutant exposure, and the composition of microbiota, contribute to the establishment of epigenetic changes that can not only modulate the individual adaptation to the environment but also have an influence on lifelong health and disease by modifying inflammatory molecular pathways and the immune response. Postnatal intestinal colonization, in turn determined by maternal flora, mode of delivery, early skin-to-skin contact and neonatal diet, leads to specific epigenetic signatures that can affect the barrier properties of gut mucosa and their protective role against later insults, thus potentially predisposing to the development of late-onset inflammatory diseases. The aim of this review is to outline the epigenetic mechanisms of programming and development acting within early-life stages and to examine in detail the role of maternal and neonatal nutrition, microbiota composition, and other environmental factors in determining epigenetic changes and their short- and long-term effects.

Obesity and cancer: the role of adipose tissue and adipo-cytokines-induced chronic inflammation

Adipose tissue in addition to its ability to keep lipids is now recognized as a real organ with both metabolic and endocrine functions. Recent studies demonstrated that in obese animals is established a status of adipocyte hypoxia and in this hypoxic state interaction between adipocytes and stromal vascular cells contribute to tumor development and progression. In several tumors such as breast, colon, liver and prostate, obesity represents a poor predictor of clinical outcomes. Dysfunctional adipose tissue in obesity releases a disturbed profile of adipokines with elevated levels of pro-inflammatory factors and a consequent alteration of key signaling mediators which may be an active local player in establishing the peritumoral environment promoting tumor growth and progression. Therefore, adipose tissue hypoxia might contribute to cancer risk in the obese population. To date the precise mechanisms behind this obesity-cancer link is not yet fully understood. In the light of information provided in this review that aims to identify the key mechanisms underlying the link between obesity and cancer we support that inflammatory state specific of obesity may be important in obesity-cancer link.

The effects of pre-pregnancy BMI and maternal factors on the timing of adiposity rebound in offspring

OBJECTIVE

To assess the effect of pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and other maternal factors on the timing of adiposity rebound (AR).

METHODS

In this study, 594 mothers (mothers who do not have diabetes and not underweight) from the longitudinal Growth and Obesity Chilean Cohort Study self-reported their weights at the beginning and end of their pregnancies, and their heights were measured. Pre-pregnancy BMI was categorized as normal weight, overweight, or obesity, and GWG was assessed according to Institute of Medicine guidelines. For children, weight and height measurements from 0 to 3 years were retrieved from records, and they were measured from age 4 to 7 years. BMI curves from 0 to 7 years were used to estimate the age at AR, which was categorized as early (<5 years), intermediate (5-7 years), or late (>7 years). The associations between pre-pregnancy BMI and GWG and early AR were tested using logistic regression models.

RESULTS

In total, 33% of the mothers had excess pre-pregnancy weight, 31.2% exceeded Institute of Medicine recommendations, and 45% of children had early AR. The pre-pregnancy BMI and parity were associated with earlier AR (OR = 1.07, 95% CI = 1.02-1.11; OR = 0.86; 95% CI = 0.74-0.99, respectively), but GWG was unrelated.

CONCLUSIONS

These results suggest that preventive strategies for promoting normal pre-pregnancy BMI, especially in women's first pregnancies, could delay the timing of AR, with protective metabolic effects on offspring.

Serum level and polymorphisms of retinol-binding protein-4 and risk for gestational diabetes mellitus: a meta-analysis

BACKGROUND

Retinol-binding protein-4 (RBP4) has been reported to be potentially involved in the pathogenesis of gestational diabetes mellitus (GDM); however, the findings are inconsistent. Our aims were to review the studies that investigated the association of serum levels and polymorphisms of RBP4 with GDM risk, and to provide recommendations for future research.

METHODS

The databases PubMed, EBSCO, ScienceDirect, and Web of Knowledge were searched up to October 2015 to find out studies evaluating the relationship between serum RBP4 level/ RBP4 polymorphisms and GDM risk. In the meta-analysis of serum RBP4 levels the key inclusion was that studies were designed as BMI-matched studies or had observed non-significant differences in BMI between cases and controls.

RESULTS

Fourteen case-control studies (647 cases and 620 controls) reporting the association between serum RBP4 level and GDM risk, and three studies (1012 cases and 1605 controls) investigating the association between RBP4 polymorphisms and GDM risk were involved. Our results showed that high serum RBP4 levels represent a risk factor for GDM (pooled standardized mean difference =0.758, 95% confidence interval [0.387, 1.128]). The results of subgroup analyses based on "gestational age at blood sampling" or "diagnostic criteria" are consistent with the overall results. However, the postpartum subgroup and "before 24 weeks" subgroup both only include one article and indicate no association between serum RBP4 level and GDM risk. The meta-analysis on the association between rs3758539 polymorphism and GDM risk shows that RBP4 rs3758539 polymorphism is not associated with the development of GDM.

CONCLUSIONS

The results of this meta-analysis support the hypothesis that RBP4 is a modest independent risk factor for GDM (i.e., nonobese patients with GDM might express RBP4 at abnormal levels). The serum RBP4 level is associated with the risk of GDM. However, the association in the first-trimester and postpartum period should be validated by further research. The association between RBP4 rs3758539 polymorphism and GDM risk was not confirmed.

Maternal and Fetal Lipid and Adipokine Profiles and Their Association with Obesity

Background. Maternal metabolic changes impact fetal metabolism resulting in a higher risk for developing chronic diseases later in life. The aim of this study was to assess the association between maternal and fetal adipokine and lipid profiles, as well as the influence of maternal weight on this association. Methods. Healthy pregnant women at term who delivered by C-section were enrolled. Maternal and fetal glucose, lipid profile, adiponectin, leptin, and resistin levels were analyzed by obesity and maternal weight gain. Statistics included descriptives, correlations, and mean differences (SPSS v20.0). Results. Adiponectin and resistin concentrations were higher in fetal blood, while leptin was lower (p < 0.05). A significant inverse association between maternal resistin and fetal LDL-cholesterol (LDL-C) (r = -0.327; p = 0.022) was observed. A positive correlation was found between maternal and fetal resistin (r = 0.358; p = 0.013). Women with excessive weight gain had higher leptin levels and their fetuses showed higher LDL-C levels (p < 0.05). Conclusions. Maternal resistin showed an inverse association with fetal LDL-C, suggesting that maternal adiposity status may play an active role in the regulation of fetal lipid profile and consequently, in fetal programming. Excessive maternal weight gain during pregnancy may exert an effect over metabolic mediators in both mother and newborn.

Obesity and Maternal Weight Gain

Pregnancy is a time when women may be receptive to health advice and interventions. This article considers the evidence for interventions to affect body weight in obese and overweight women delivered either or both pre- and post-natally. The increasing prevalence of obesity across the adult population has affected many sectors of society and increasing numbers of obese and overweight pregnant women are evident. Obesity in pregnancy is frequently associated with excessive gestational weight gains and increases the risk of developing adverse pregnancy outcomes in terms of both maternal and infant health. Pregnancy has been described as providing "a teachable moment" when women may be receptive to health advice. Some lifestyle approaches, largely incorporating strategies to alter dietary and physical activity to challenge excess body weight before and during pregnancy, have been developed and tested. While a few have shown promise with limited success in reducing body weight prior to pregnancy and post-natally, and minimising excessive weight gains during pregnancy, all interventions are not sufficiently robust and effective to justify routine inclusion in clinical practice. Weight management pre- and post-natally appears largely overlooked in usual care.

Experimental gestational diabetes mellitus induces blunted vasoconstriction and functional changes in the rat aorta

Diabetic conditions increase vascular reactivity to angiotensin II in several studies but there are scarce reports on cardiovascular effects of hypercaloric diet (HD) induced gestational diabetes mellitus (GDM), so the objective of this work was to determine the effects of HD induced GDM on vascular responses. Angiotensin II as well as phenylephrine induced vascular contraction was tested in isolated aorta rings with and without endothelium from rats fed for 7 weeks (4 before and 3 weeks during pregnancy) with standard (SD) or hypercaloric (HD) diet. Also, protein expression of AT₁R, AT₂R, COX-1, COX-2, NOS-1, and NOS-3 and plasma glucose, insulin, and angiotensin II levels were measured. GDM impaired vasoconstrictor response (P < 0.05 versus SD) in intact (e+) but not in endothelium-free (e−) vessels. Losartan reduced GDM but not SD e− vasoconstriction (P < 0.01 versus SD). AT₁R, AT₂R, and COX-1 and COX-2 protein expression were significantly increased in GDM vessels (P < 0.05 versus SD). Results suggest an increased participation of endothelium vasodilator mediators, probably prostaglandins, as well as of AT₂ vasodilator receptors as a compensatory mechanism for vasoconstrictor changes generated by experimental GDM. Considering the short term of rat pregnancy findings can reflect early stage GDM adaptations.