Convergence in insulin resistance between very severely obese and lean women at the end of pregnancy

Maternal metabolic profiling across body mass index groups: An exploratory longitudinal study

INTRODUCTION

Increased BMI has been identified as a risk factor for most pregnancy complications, but the underlying metabolic factors mediating the detrimental effects of BMI are largely unknown. We aimed to compare metabolic profiles in overweight/obese women (body mass index [BMI] ≥ 25 kg/m2 ) and normal weight/underweight women (BMI < 25 kg/m2 ) across gestation. We also explored how gestational weight gain (GWG) affected maternal metabolic profiles.

MATERIAL AND METHODS

Exploratory nested case-control study based on a prospective longitudinal cohort of women who were healthy prior to pregnancy and gave birth at Oslo University Hospital from 2002 to 2008. The sample consisted of 48 women who were overweight/obese and 59 normal-weight/underweight women. Plasma samples from four time points in pregnancy (weeks 14-16, 22-24, 30-32 and 36-38) were analyzed by nuclear magnetic resonance spectroscopy and 91 metabolites were measured. Linear regression models were fitted for each of the metabolites at each time point.

RESULTS

Overweight or obese women had higher levels of lipids in very-low-density lipoprotein (VLDL), total triglycerides, triglycerides in VLDL, total fatty acids, monounsaturated fatty acids, saturated fatty acids, leucine, valine, and total branched-chain amino acids in pregnancy weeks 14-16 compared to underweight and normal-weight women. Docosahexaenoic acid and degree of unsaturation were significantly lower in overweight/obese women in pregnancy weeks 36-38. In addition, overweight or obese women had higher particle concentration of XXL-VLDL and glycoprotein acetyls (GlycA) at weeks 14-16 and 30-32. GWG did not seem to affect the metabolic profile, regardless of BMI group when BMI was treated as a dichotomous variable, ≥25 kg/m2 (yes/no).

CONCLUSIONS

Overweight or obese women had smaller pregnancy-related metabolic alterations than normal-weight/underweight women. There was a trend toward higher triglyceride and VLDL particle concentration in overweight/obese women. As this was a hypothesis-generating study, the similarities with late-onset pre-eclampsia warrant further investigation. The unfavorable development of fatty acid composition in overweight/obese women, with possible implication for the offspring, should also be studied further in the future.

Parity modulates impact of BMI and gestational weight gain on gut microbiota in human pregnancy

Dysregulation of maternal adaptations to pregnancy due to high pre-pregnancy BMI (pBMI) or excess gestational weight gain (GWG) is associated with worsened health outcomes for mothers and children. Whether the gut microbiome contributes to these adaptations is unclear. We longitudinally investigated the impact of pBMI and GWG on the pregnant gut microbiome. We show that the gut microbiota of participants with higher pBMI changed less over the course of pregnancy in primiparous but not multiparous participants. This suggests that previous pregnancies may have persistent impacts on maternal adaptations to pregnancy. This ecological memory appears to be passed on to the next generation, as parity modulated the impact of maternal GWG on the infant gut microbiome. This work supports a role of the gut microbiome in maternal adaptations to pregnancy and highlights the need for longitudinal sampling and accounting for parity as key considerations for studies of the microbiome in pregnancy and infants. Understanding how these factors contribute to and shape maternal health is essential for the development of interventions impacting the microbiome, including pre/probiotics.

Addressing inequalities and improving maternal and infant outcomes: the potential power of nutritional interventions across the reproductive cycle

Maternal nutrition is essential for optimal health and well-being of women and their infants. This review aims to provide a critical overview of the evidence-base relating to maternal weight, obesity-related health inequalities and dietary interventions encompassing the reproductive cycle: preconception, pregnancy, postnatal and interpregnancy. We provide an overview of UK data showing that overweight and obesity affects half of UK pregnancies, with increased prevalence among more deprived and minoritised ethnic populations, and with significant health and cost implications. The existing intervention evidence-base primarily focuses on the pregnancy period, where extensive evidence demonstrates the power of interventions to improve maternal diet behaviours, and minimise gestational weight gain and postnatal weight retention. There is a lack of consistency in the intervention evidence-base relating to interventions improving pregnancy health outcomes, although there is evidence of the potential power of the Mediterranean and low glycaemic index diets in improving short- and long-term health of women and their infants. Postnatal interventions focus on weight loss, with some evidence of cost-effectiveness. There is an evidence gap for preconception and interpregnancy interventions. We conclude by identifying that interventions do not address cumulative maternal obesity inequalities and overly focus on individual behaviour change. There is a lack of a joined-up approach for interventions throughout the entire reproductive cycle, with a current focus on specific stages (i.e. pregnancy) in isolation. Moving forward, the potential power of nutritional interventions using a more holistic approach across the different reproductive stages is needed to maximise the benefits on health for women and children.

Intestinal permeability and peripheral immune cell composition are altered by pregnancy and adiposity at mid- and late-gestation in the mouse

It is clear that the gastrointestinal tract influences metabolism and immune function. Most studies to date have used male test subjects, with a focus on effects of obesity and dietary challenges. Despite significant physiological maternal adaptations that occur across gestation, relatively few studies have examined pregnancy-related gut function. Moreover, it remains unknown how pregnancy and diet can interact to alter intestinal barrier function. In this study, we investigated the impacts of pregnancy and adiposity on maternal intestinal epithelium morphology, in vivo intestinal permeability, and peripheral blood immunophenotype, using control (CTL) and high-fat (HF) fed non-pregnant female mice and pregnant mice at mid- (embryonic day (E)14.5) and late (E18.5) gestation. We found that small intestine length increased between non-pregnant mice and dams at late-gestation, but ileum villus length, and ileum and colon crypt depths and goblet cell numbers remained similar. Compared to CTL-fed mice, HF-fed mice had reduced small intestine length, ileum crypt depth and villus length. Goblet cell numbers were only consistently reduced in HF-fed non-pregnant mice. Pregnancy increased in vivo gut permeability, with a greater effect at mid- versus late-gestation. Non-pregnant HF-fed mice had greater gut permeability, and permeability was also increased in HF-fed pregnant dams at mid but not late-gestation. The impaired maternal gut barrier in HF-fed dams at mid-gestation coincided with changes in maternal blood and bone marrow immune cell composition, including an expansion of circulating inflammatory Ly6Chigh monocytes. In summary, pregnancy has temporal effects on maternal intestinal structure and barrier function, and on peripheral immunophenotype, which are further modified by HF diet-induced maternal adiposity. Maternal adaptations in pregnancy are thus vulnerable to excess maternal adiposity, which may both affect maternal and child health.

Maternal metabolic syndrome in pregnancy and child development at age 5: exploring mediating mechanisms using cord blood markers

BACKGROUND

There is limited evidence on how the classification of maternal metabolic syndrome during pregnancy affects children's developmental outcomes and the possible mediators of this association. This study uses a cohort sample of 12,644 to 13,832 mother-child pairs from the UK Born in Bradford Study to examine the associations between maternal metabolic syndrome classification (MetS) and child development outcomes at age 5, using cord blood markers as candidate mediators.

METHODS

Maternal cardiometabolic markers included diabetes, obesity, triglycerides, high-density lipoprotein cholesterol, blood pressure, hypertension, and fasting glucose during pregnancy. Cord blood markers of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, leptin, and adiponectin were used as child mediators. Child outcomes included two starting school variables: British Picture Vocabulary Scale (BPVS) and the Letter Identification Assessment (LID), and five developmental milestone domains from a national UK framework: (1) communication and language (COM); (2) personal, social, and emotional (PSE); (3) physical development (PHY); (4) literacy (LIT); and (5) mathematics (MAT). Mediation models were used to examine the associations between the classification of maternal metabolic syndrome and child developmental milestones. Models were adjusted for potential maternal, socioeconomic, and child confounders such as maternal education, deprivation, and gestational age.

RESULTS

In mediation models, significant total effects were found for MetS associations with children's development in the LIT domain at age 5. MetS predicted individual cord blood mediators of lower HDL and increased leptin levels in both adjusted and unadjusted models. Total indirect effects (effects of all mediators combined) for MetS on a child's COM and PSE domain were significant, through all child cord blood mediators of LDL, HDL, triglycerides, adiponectin, and leptin for adjusted models.

CONCLUSIONS

The results support the hypothesis that maternal metabolic syndrome classification during pregnancy is associated with some child developmental outcomes at age 5. After adjusting for maternal, child, and environmental covariates, maternal metabolic syndrome classification during pregnancy was associated with children's LIT domain through direct effects of maternal metabolic health and indirect effects of cord blood markers (total effects), and COM and PSE domains via changes only in a child's cord blood markers (total indirect effects).

Ethnic Disparities and Obesity Risk Factors in Pregnant Women: A Retrospective Observational Cohort Study

(1) Background: This article focuses on the prevalence of overweight and obesity in pregnancy in different ethnic groups and assesses the existence of associated comorbidities. (2) Materials and Methods: A retrospective observational cohort study of 16803 pregnant women was carried out between 2012 and 2018 in the health region of Lleida (72% of the total). The relationship between overweight and obesity and different variables was analyzed by calculating the adjusted odds ratio (aOR) and 95% confidence intervals with multivariate logistic regression models. (3) Results: The prevalence of obesity in pregnant women rose from 11.1% in 2012 to 13.4% in 2018, and there was an age-related weight gain. A high incidence of overweight and obesity was recorded in pregnant women from ethnic groups: Maghrebi, sub-Saharan African and Latin America populations presented ORs of 4.08, 3.18 and 1.59, respectively. Hypertension was the variable most affected by body mass index (BMI) > 25 (OR = 3.39) followed by gestational diabetes mellitus (OR = 2.35). Depression was also associated with obesity. (4) Conclusions: The BMI of pregnant women is influenced by individual, ethnic and clinical factors. Mental health conditions such as depression are associated with BMI.

Role of Perinatal Biological Factors in Delayed Lactogenesis II Among Women With Pre-pregnancy Overweight and Obesity

BACKGROUND

Pre-pregnancy overweight and obesity are negatively associated with delayed onset of lactogenesis II (OL), but the mechanisms by which these conditions affect OL are still unclear.

OBJECTIVES

To identify biological factors related to pre-pregnancy overweight/obesity and determine whether these biological factors were associated with delayed OL in this population.

METHODS

In this prospective observational study, we assigned 72 primipara to a pre-pregnancy overweight/obese group (n = 36) and a normal-weight group (n = 36). Blood samples were collected at 37 w of gestation and 48 h postpartum and assayed for levels of the following hormones: leptin, insulin, estradiol, prolactin (PRL), progesterone, and oxytocin. The primary outcome was timing of OL, estimated by maternal perception of breast fullness. We used linear-regression analysis to determine associations between hormones and delayed OL.

RESULTS

Sixty-three participants (87.5%) had complete data. OL occurred later in overweight/obese than in normal-weight women (p < .001). Compared with the normal-weight group, the overweight/obese group showed higher leptin levels at both times of observation and exhibited a slower drop in estrogen concentrations from 37 w of gestation to 48 h postpartum (all p < .05). After adjusting for confounding factors, leptin concentrations in late pregnancy and the magnitudes of decline in estrogen concentrations at 48 h postpartum were correlated with OL.

CONCLUSION

Women who were overweight/obese before pregnancy had elevated leptin levels in late pregnancy and a delayed decline in estrogen concentrations at 48 h postpartum. Both of these phenomena were related to delayed OL in this population.

The conceptual framework for a combined food literacy and physical activity intervention to optimize metabolic health among women of reproductive age in urban Uganda

Background

Metabolic health of urban Ugandans, mostly women, has increasingly become sub-optimal. As women are strategic for family behavioral change and do not meet WHO recommendations regarding dietary and physical activity (PA), there is an urgent need for science-based interventions to tackle unhealthy dietary and PA behaviors.

Objective

To develop a food literacy and PA promotion intervention to optimise metabolic health among women of reproductive age in urban Uganda.

Methodology

Steps 1- 6 of the Intervention Mapping protocol were used to design the intervention.

Results

Notable determinants from Step 1 were health/beauty paradox, nonfactual nutrition information, socio-cultural misconceptions around moderate PA, fruits, and vegetables. Others included gaps in food/PA knowledge, skills, and self-efficacy. We hypothesised that changing the overall existing behaviours in one intervention may meet strong resistance. Thus, we decided to go for gradual stepwise changes. Hence in step 2, three behavioural intervention objectives were formulated; (1) women evaluate the accuracy of nutrition and PA information., (2) engage in moderate intensity PA for at least 150 min a week, and (3) consume at least one portion of vegetables and one portion of fruit every day. Based on the food literacy model, intervention objectives were formulated into performance objectives and matrices of change objectives. In step 3 a combination of eleven behavioural change techniques were selected and translated into practical strategies to effect changes in determinants. In step 4, intervention components and materials were developed. The intervention consists of five interactive group sessions, 150 min each. Infographics on benefits/recommendations, vegetable recipes, and practical tips to eat more fruits, vegetables, and to engage more in PA are included. Personalised goals and action plans tailored to personal metabolic health and lifestyle needs, and environmental opportunities form the basis of the intervention. A randomized controlled trial is being conducted to evaluate the intervention (https://clinicaltrials.gov/ct2/show/NCT04635332).

Conclusions

The intervention is novel, based on a holistic food literacy model. The intervention is built on determinants specific to urban Uganda, evidence based behavioural change theoretical models and techniques, detailing the hypothesised behavioural change mechanism. If effective, an evidence-based intervention will become available for reference in urban Uganda.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12740-w.

Longitudinal Metabolic Profiling of Maternal Obesity, Gestational Diabetes, and Hypertensive Pregnancy Disorders

CONTEXT

Comprehensive assessment of metabolism in maternal obesity and pregnancy disorders can provide information about the shared maternal-fetal milieu and give insight into both maternal long-term health and intergenerational transmission of disease burden.

OBJECTIVE

To assess levels, profiles, and change in the levels of metabolic measures during pregnancies complicated by obesity, gestational diabetes (GDM), or hypertensive disorders.

DESIGN, SETTING AND PARTICIPANTS

A secondary analysis of 2 study cohorts, PREDO and RADIEL, including 741 pregnant women.

MAIN OUTCOME MEASURES

We assessed 225 metabolic measures by nuclear magnetic resonance in blood samples collected at median 13 [interquartile range (IQR) 12.4-13.7], 20 (IQR 19.3-23.0), and 28 (27.0-35.0) weeks of gestation.

RESULTS

Across all 3 time points women with obesity [body mass index (BMI) ≥ 30kg/m2] in comparison to normal weight (BMI 18.5-24.99 kg/m2) had significantly higher levels of most very-low-density lipoprotein-related measures, many fatty and most amino acids, and more adverse metabolic profiles. The change in the levels of most metabolic measures during pregnancy was smaller in obese than in normal weight women. GDM, preeclampsia, and chronic hypertension were associated with metabolic alterations similar to obesity. The associations of obesity held after adjustment for GDM and hypertensive disorders, but many of the associations with GDM and hypertensive disorders were rendered nonsignificant after adjustment for BMI and the other pregnancy disorders.

CONCLUSIONS

This study shows that the pregnancy-related metabolic change is smaller in women with obesity, who display metabolic perturbations already in early pregnancy. Metabolic alterations of obesity and pregnancy disorders resembled each other suggesting a shared metabolic origin.

Metabolic flexibility during normal pregnancy allows appropriate adaptation during gestation independently of BMI

BACKGROUND & AIMS

Overweight and obesity in reproductive-age women hasten the development of insulin resistance and increase risk for deterioration of pregnancy metabolism. These pregnancy-associated metabolic changes are similar to those of the metabolic syndrome. Thus, some metabolic flexibility must allow appropriate adaptation to the metabolic load that pregnancy imposes. We evaluated metabolic flexibility during uncomplicated pregnancy in women with pre-gestational normal weight or overweight.

METHODS

In 20 women with singleton pregnancies, pre-pregnancy BMI was categorized as normal-weight (Nw) or overweight (Ow). The women were seen quarterly, and fasting and postprandial blood samples were collected at each visit. Indirect fasting and/postprandial calorimetry was performed to evaluate metabolic flexibility (Δrespiratory quotient (RQ) = RQ_postprandial - RQ_fasting).

RESULTS

In the first trimester, metabolic flexibility was lower in the Ow group compared to the Nw group (0.031 ± 0.0131 vs 0.077 ± 0.018, respectively) without a statistically significant difference (p = 0.053). In the second trimester, the Ow group was significantly more flexible than the Nw group (0.190 ± 0.016 vs 0.077 ± 0.015, respectively (p = 0.004)). For the third trimester, the Ow and Nw groups did not differ in metabolic flexibility (0.074 ± 0.013 vs 0.087 ± 0.021, respectively) (p = 0.40). The most influential variables for metabolic flexibility during pregnancy were lactate, leptin, β-hydroxybutyrate, glycerol, aromatic amino acids, medium and long chain acylcarnitine's.

CONCLUSIONS

Our findings indicate that metabolic flexibility changes throughout pregnancy, independently of pre-pregnancy BMI. These changes maintain metabolic homeostasis between the mother and foetus, allowing for appropriate adjustments during pregnancy.

Insulin Requirements and Carbohydrate to Insulin Ratio in Normal Weight, Overweight, and Obese Women With Type 1 Diabetes Under Pump Treatment During Pregnancy: A Lesson From Old Technologies

AIM

The primary aim of this study was to assess insulin requirements and carbohydrate to insulin ratio (CHO/IR) in normal weight, overweight, and obese pregnant women with type 1 diabetes across early, middle, and late pregnancy.

METHODS

In this multicenter, retrospective, observational study we evaluated 86 of 101 pregnant Caucasian women with type 1 diabetes under pump treatment. The women were trained to calculate CHO/IR daily by dividing CHO grams of every single meal by insulin units injected. Since the purpose of the study was to identify the CHO/IR able to reach the glycemic target, we only selected the CHO/IR obtained when glycemic values were at target. Statistics: SPSS 20.

RESULTS

We studied 45 normal weight, 31 overweight, and 10 obese women. Insulin requirements increased throughout pregnancy (p < 0.0001 and <0.001 respectively) in the normal and overweight women, while it remained unchanged in the obese women. Insulin requirements were different between groups when expressed as an absolute value, but not when adjusted for body weight. Breakfast CHO/IR decreased progressively throughout pregnancy in the normal weight women, from 13.3 (9.8-6.7) at the first stage of pregnancy to 6.2 (3.8-8.6) (p = 0.01) at the end stage, and in the overweight women from 8.5 (7.1-12.6) to 5.2 (4.0-8.1) (p = 0.001), while in the obese women it remained stable, moving from 6.0 (5.0-7.9) to 5.1 (4.1-7.4) (p = 0.7). Likewise, lunch and dinner CHO/IR decreased in the normal weight and overweight women (p < 0.03) and not in the obese women. The obese women gained less weight than the others, especially in early pregnancy when they even lost a median of 1.25 (-1 -1.1) kg (p = 0.005). In early pregnancy, we found a correlation between pregestational BMI and insulin requirements (IU/day) or CHO/IR at each meal (p < 0.001 and p = 0.001, respectively). In late pregnancy, a relationship between pre-gestational BMI and CHO/IR change was found (P = 0.004), as well as between weight gain and CHO/IR change (p=0.02). The significance was lost when both variables were included in the multiple regression analysis. There was no difference in pregnancy outcomes except for a higher pre-term delivery rate in the obese women.

CONCLUSION

Pre-gestational BMI and weight gain may play a role in determining CHO/IR during pregnancy in women with type 1 diabetes under pump treatment.

Quantitative systematic review: Methods used for the in vivo measurement of body composition in pregnancy

AIMS

Because of the increased overall prevalence of pre-pregnancy obesity among racial-ethnic groups, we conducted a review of published methods for body composition measurement during pregnancy considering at present there is no consensus on the best practices and type of study design that researchers should use for this purpose.

DESIGN

Quantitative systematic review.

DATA SOURCES

PubMed, EMBASE, Scopus, Web of Science, and Virtual Library of Health. Search dates from 1997-2016.

REVIEW METHODS

Search of articles indexed in selected databases from 1997-2016. Studies were published in English, Spanish, and Portuguese. Graphs were carried out using data visualization software.

RESULTS

From the 112 included studies, 70 were prospective cohorts, 30 cross-sectional studies, 10 randomized controlled trial, and two retrospective studies. Cross-sectional studies and randomized controlled trial depicted a positive correlation with significant trend.

CONCLUSIONS

Although several methods for body composition measurement exist, only bioelectrical impedance analysis, displacement plethysmography, and displacement plethysmography show a significant growing trend. Use of data visualization allows understanding various associations among categorical variables, with a graphical display of their multidimensional behaviour.

IMPACT

Public and private health-care institution evaluating pregnancy women. Health-care personnel, including nursing professional, dealing with measurements of body composition during pregnancy will find reading this manuscript beneficial.

Vitamin B12 deficiency and altered one-carbon metabolites in early pregnancy is associated with maternal obesity and dyslipidaemia

Vitamin B12 (B12) is a micronutrient essential for one-carbon (1C) metabolism. B12 deficiency disturbs the 1C cycle and alters DNA methylation which is vital for most metabolic processes. Studies show that B12 deficiency may be associated with obesity, insulin resistance and gestational diabetes; and with obesity in child-bearing women. We therefore hypothesised that the associations between B12 deficiency, BMI and the metabolic risk could be mediated through altered 1C metabolites in early pregnancy. We explored these associations in two different early pregnancy cohorts in the UK (cohort 1; n = 244 and cohort 2; n = 60) with anthropometric data at 10-12 weeks and plasma/serum sampling at 16-18 weeks. B12, folate, total homocysteine (tHcy), methionine, MMA, metabolites of 1C metabolism (SAM, SAH) and anthropometry were measured. B12 deficiency (< 150 pmol/l) in early pregnancy was 23% in cohort 1 and 18% in cohort 2. Regression analysis after adjusting for likely confounders showed that B12 was independently and negatively associated with BMI (Cohort 1: β = - 0.260, 95% CI (- 0.440, - 0.079), p = 0.005, Cohort 2: (β = - 0.220, 95% CI (- 0.424, - 0.016), p = 0.036) and positively with HDL cholesterol (HDL-C) (β = 0.442, 95% CI (0.011,0.873), p = 0.045). We found that methionine (β = - 0.656, 95% CI (- 0.900, - 0.412), p < 0.0001) and SAH (β = 0.371, 95% CI (0.071, 0.672), p = 0.017) were independently associated with triglycerides. Low B12 status and alteration in metabolites in 1C metabolism are common in UK women in early pregnancy and are independently associated with maternal obesity and dyslipidaemia. Therefore, we suggest B12 monitoring in women during peri-conceptional period and future studies on the pathophysiological relationship between changes in 1C metabolites and its association with maternal and fetal outcomes on larger cohorts. This in turn may offer potential to reduce the metabolic risk in pregnant women and their offspring.

When and How Should Chinese Pregnant Women Exercise? A Longitudinal Study in China

This study aimed to examine when and how physical activity (PA) influences gestational weight gain (GWG) and infant birthweight (BW) by considering the PA’s total volume, timing, intensity, and type, controlling for the influence of energy intake. A total of 1272 participants in different stages of pregnancy were recruited from hospital. The associations between PA and GWG or BW in the latter half of pregnancy were significant. Women with the highest PA volume in the third trimester had significantly lower risks of inadequate and excessive GWG by 69% (OR = 0.31, 95%CI: 0.10–0.91) and 67% (OR = 0.33, 95% CI: 0.12–0.91), respectively, compared to women in the lowest quartile. Women who achieved the recommended moderate intensity of PA during their second and third trimesters, independent of total volume of PA, had infants with significantly lower BWs compared to those who did not (β = −0.15, SE = 66.33, p = 0.04; β = −0.20, SE = 64.54, p = 0.01, respectively). Therefore, the effects of total volume and intensity of PA on GWG and BW were different. Interventions to prevent inappropriate GWG and macrosomia may need to set different priorities and timing regarding total volume or intensity of PA.

Consequences of being overweight or obese during pregnancy on diabetes in the offspring: a record linkage study in Aberdeen, Scotland

AIMS/HYPOTHESIS

Maternal obesity in pregnancy is associated with cardiovascular disease and mortality rate in the offspring. We aimed to determine whether maternal obesity is also associated with increased incidence of type 2 and type 1 diabetes in the offspring, independently of maternal diabetes as a candidate mechanistic pathway.

METHODS

Birth records of 118,201 children from 1950 to 2011 in the Aberdeen Maternity and Neonatal Databank were linked to Scottish Care Information-Diabetes, the national register for diagnosed diabetes in Scotland, to identify incident and prevalent type 1 and type 2 diabetes up to 1 January 2012. Maternal BMI was calculated from height and weight measured at the first antenatal visit. The effect of maternal obesity on offspring outcomes was tested using time-to-event analysis with Cox proportional hazards regression to compare outcomes in offspring of mothers in underweight, overweight or obese categories of BMI, compared with offspring of women with normal BMI.

RESULTS

Offspring of obese (BMI ≥30 kg/m²) and overweight (BMI 25-29.9 kg/m²) mothers had an increased hazard of type 2 diabetes compared with mothers with normal BMI, after adjustment for gestation when weight was measured, maternal history of diabetes before pregnancy, maternal history of hypertension, age at delivery, parity, socioeconomic status, and sex of the offspring: HR 3.48 (95% CI 2.33, 5.06) and HR 1.39 (1.06, 1.83), respectively.

CONCLUSIONS/INTERPRETATION

Maternal obesity is associated with increased incidence of type 2 diabetes in the offspring. Evidence-based strategies that reduce obesity among women of reproductive age and that might reduce the incidence of diabetes in their offspring are urgently required.

Higher Numbers of Pregnancies Associated With an Increased Prevalence of Gestational Diabetes Mellitus: Results From the Healthy Baby Cohort Study

Background

Pregnancy leads to substantial maternal metabolic and lifestyle alterations. However, it is still unclear whether repeated exposure to these changes will influence the development of gestational diabetes mellitus (GDM). In the present study, we aimed to investigate the association between the number of pregnancies and GDM among Chinese women.

Methods

A total of 7,008 subjects from the Healthy Baby Cohort study were included in this study. The number of pregnancies was classified into three categories: 1, 2, or ≥3 pregnancies. GDM was diagnosed using International Association of Diabetes and Pregnancy Study Groups criteria. Multivariate logistic regression models were used.

Results

In the fully adjusted model, women with ≥3 pregnancies had a 1.27-fold (95% confidence interval [CI], 1.05–1.54) higher risk of GDM. Among women ≥30 years old, 2 and ≥3 pregnancies were associated with a higher risk of GDM (odds ratio [OR] 1.32; 95% CI, 1.01–1.73 and OR 1.54; 95% CI, 1.17–2.01, respectively). Among women with a pre-pregnancy BMI <24 kg/m², ≥3 pregnancies were associated with a 1.35-fold (95% CI, 1.09–1.67) higher risk of GDM.

Conclusions

Our findings suggested that higher numbers of pregnancies is an independent risk factor of GDM. The association between number of pregnancies and GDM was more prominent among women who were ≥30 years old or with a pre-pregnancy BMI <24 kg/m².

Obesity Disrupts Rhythmic Clock Gene Expression in Maternal Adipose Tissue during Rat Pregnancy

Obesity during pregnancy causes numerous maternal and fetal health complications, but the underlying mechanisms remain unclear. Adipose tissue dysfunction in obesity has previously been linked to disruption of the intrinsic adipose clock gene network that is crucial for normal metabolic function. This adipose clock also undergoes major change as part of the maternal metabolic adaptation to pregnancy, but whether this is affected by maternal obesity is unknown. Consequently, in this study we tested the hypothesis that obesity disturbs rhythmic gene expression in maternal adipose tissue across pregnancy. A rat model of maternal obesity was established by cafeteria (CAF) feeding, and adipose expression of clock genes and associated nuclear receptors ( Ppars and Pgc1α) was measured across days 15-16 and 21-22 of gestation (term = 23 days). CAF feeding suppressed the mesor and/or amplitude of adipose tissue clock genes (most notably Bmal1, Per2, and Rev-erbα) relative to chow-fed controls (CON) across both days of gestation. On day 15, the CAF diet also induced adipose Pparα, Pparδ, and Pgc1α rhythmicity but repressed that of Pparγ, while expression of Pparα, Pparδ, and Pgc1α was reduced at select time points. CAF mothers were hyperleptinemic at both stages of gestation, and at day 21 this effect was time-of-day dependent. Fetal plasma leptin exhibited clear rhythmicity, albeit with low amplitude, but interestingly these levels were unaffected by CAF feeding. Our data show that maternal obesity disrupts rhythmic expression of clock and metabolic genes in maternal adipose tissue and leads to maternal but not fetal hyperleptinemia.

Experiences related to health promotion behaviors in overweight pregnant women: a qualitative study

BACKGROUND

The adoption of health behaviors by pregnant women causes their improved health and achievement of appropriate pregnancy outcomes as well as improving the quality of life of the mother and infant. Limited studies have examined such behaviors in pregnant women, especially in overweight mothers. The purpose of this study was to explore the experiences of overweight pregnant women in relation to lifestyle changes during pregnancy to improve their health.

METHODS

This qualitative study was carried out with content analysis approach in Tabriz-Iran in 2017. Using purposive sampling, pregnant women with the Body Mass Index of overweight at the preconception were selected considering other inclusion criteria and the sampling was continued to saturate the findings. The data were collected by the first author through semi-structured face-to-face interviews with 32 overweight pregnant women through 18 deep individual interviews and three group interviews. The MAXQDA software version 10 was used for data analysis. Data strength was confirmed by participants and external control.

RESULTS

Most participants were Primigravida 20 (62.5%) and with high-level education 25 (78.1%). Qualitative data analysis led to the emergence of three main themes: "physical self-care", "mental self-care", and "risk perception". The first two themes present the nature of health promotion behaviors in overweight pregnant women; the third theme expresses their feelings and perception of behaviors related to health promotion.

CONCLUSION

Health promoting behaviors include behavioral and cognitive actions resulting from a perception of the risk caused by overweight pregnant mothers. Therefore, pregnancy is the right time to evaluate behaviors and to use high motivation of women to guide them in choosing healthy behaviors and helping them to adhere to health related behaviors.

Metabolic syndrome in pregnancy and risk for adverse pregnancy outcomes: A prospective cohort of nulliparous women

BACKGROUND

Obesity increases the risk for developing gestational diabetes mellitus (GDM) and preeclampsia (PE), which both associate with increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) associates with T2DM and CVD. The impact of maternal MetS on pregnancy outcomes, in nulliparous pregnant women, has not been investigated.

METHODS AND FINDINGS

Low-risk, nulliparous women were recruited to the multi-centre, international prospective Screening for Pregnancy Endpoints (SCOPE) cohort between 11 November 2004 and 28 February 2011. Women were assessed for a range of demographic, lifestyle, and metabolic health variables at 15 ± 1 weeks' gestation. MetS was defined according to International Diabetes Federation (IDF) criteria for adults: waist circumference ≥80 cm, along with any 2 of the following: raised trigycerides (≥1.70 mmol/l [≥150 mg/dl]), reduced high-density lipoprotein cholesterol (<1.29 mmol/l [<50 mg/dl]), raised blood pressure (BP) (i.e., systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg), or raised plasma glucose (≥5.6 mmol/l). Log-binomial regression analyses were used to examine the risk for each pregnancy outcome (GDM, PE, large for gestational age [LGA], small for gestational age [SGA], and spontaneous preterm birth [sPTB]) with each of the 5 individual components for MetS and as a composite measure (i.e., MetS, as defined by the IDF). The relative risks, adjusted for maternal BMI, age, study centre, ethnicity, socioeconomic index, physical activity, smoking status, depression status, and fetal sex, are reported. A total of 5,530 women were included, and 12.3% (n = 684) had MetS. Women with MetS were at an increased risk for PE by a factor of 1.63 (95% CI 1.23 to 2.15) and for GDM by 3.71 (95% CI 2.42 to 5.67). In absolute terms, for PE, women with MetS had an adjusted excess risk of 2.52% (95% CI 1.51% to 4.11%) and, for GDM, had an adjusted excess risk of 8.66% (95% CI 5.38% to 13.94%). Diagnosis of MetS was not associated with increased risk for LGA, SGA, or sPTB. Increasing BMI in combination with MetS increased the estimated probability for GDM and decreased the probability of an uncomplicated pregnancy. Limitations of this study are that there are several different definitions for MetS in the adult population, and as there are none for pregnancy, we cannot be sure that the IDF criteria are the most appropriate definition for pregnancy. Furthermore, MetS was assessed in the first trimester and may not reflect pre-pregnancy metabolic health status.

CONCLUSIONS

We did not compare the impact of individual metabolic components with that of MetS as a composite, and therefore cannot conclude that MetS is better at identifying women at risk. However, more than half of the women who had MetS in early pregnancy developed a pregnancy complication compared with just over a third of women who did not have MetS. Furthermore, while increasing BMI increases the probability of GDM, the addition of MetS exacerbates this probability. Further studies are required to determine if individual MetS components act synergistically or independently.

Obesity, fertility and pregnancy: can we intervene to improve outcomes?

Rates of obesity among women of reproductive age have risen dramatically in recent decades. Obesity impacts on health of women across their reproductive lifespan with adverse effects on not only fertility and short-term complications of pregnancy, but also on longer term health outcomes for both women and their children. This places considerable burden and cost on health services. Here, we review the evidence linking maternal obesity to adverse fertility, pregnancy and longer term health outcomes for women and their children. We discuss the outcomes of recent lifestyle, pharmacological and surgical intervention studies. As many of these studies have not shown a significant improvement in clinical outcomes, we discuss the need for better study design in future trials.

Activity behaviors in lean and morbidly obese pregnant women

Interventions to increase physical activity in pregnancy are challenging for morbidly obese women. Targeting sedentary behaviors may be a suitable alternative to increase energy expenditure. We aimed to determine total energy expenditure, and energy expended in sedentary activities in morbidly obese and lean pregnant women. We administered the Pregnancy Physical Activity Questionnaire (nonobjective) and the Actical accelerometer (objective) to morbidly obese (BMI ≥ 40 kg/m²) and lean (BMI ≤ 25 Kg/m²) pregnant women recruited in early (<24 weeks), and late (≥24 weeks) gestation. Data are mean (SD). Morbidly obese pregnant women reported expending significantly more energy per day in early (n = 140 vs 109; 3198.4 (1847.1) vs 1972.3 (10284.8) Kcal/d, P < .0001) and late (n = 104 vs 64; 3078.2 (1356.5) vs 1947.5 (652.0) Kcal/d, P < .0001) pregnancy, and expended significantly more energy in sedentary activities, in early (816.1 (423.5) vs 540.1 (244.9) Kcal/d, P < .0001) and late (881.6 (455.4) vs 581.1 (248.5) Kcal/d, P < .0001) pregnancy, than lean pregnant women. No differences were observed in the proportion of energy expended sedentary between lean and morbidly obese pregnant women. The greater total energy expenditure in morbidly obese pregnant women was corroborated by Actical accelerometer in early (n = 14 per group, obese 1167.7 (313.6) Kcal; lean 781.1 (210.1) Kcal, P < .05), and in late (n = 14 per group, obese 1223.6 (351.5) Kcal; lean 893.7 (175.9) Kcal, P < .05) pregnancy. In conclusion, non-objective and objective measures showed morbidly obese pregnant women expended more energy per day than lean pregnant. Further studies are needed to determine whether sedentary behaviors are a suitable target for intervention in morbidly obese pregnancy.

Advances in assessing body composition during pregnancy

The prevalence of excess gestational weight gain is increasing worldwide and is associated with pregnancy complications, including gestational diabetes mellitus, pre-eclampsia, preterm birth, macrosomia, and development of obesity in offspring. Whereas gestational weight gain positively correlates with the gain in fat mass (FM), fat-free mass (FFM) gain is relatively consistent across pregnancies. Commonly used methods to assess body composition include anthropometry, densitometry (air displacement plethysmography, underwater weighing), and hydrometry (isotope dilution, bioimpedance analysis). While these techniques can be applied to pregnancy, they require specific adjustments to assumptions inherent within each method, most importantly to accommodate for the hydration of FFM which is transient throughout gestation. Here we discuss the application of the abovementioned methods to pregnant women and the relevant adjustments needed to more accurately calculate FM based on body weight, body volume, or total body water. We also present a novel application of classical data to provide FFM density estimates for pregnant women at any stage of pregnancy. Use of these adjustments will help standardize assumptions on FFM hydration and minimize error in FM estimation. Techniques still fail, however, to fully distinguish tissue gains between mother and fetus. To fill this important gap, imaging techniques such as ultrasound and magnetic resonance imaging are being used more frequently and will provide more insight into fetal development, fetal adiposity, and depot specificity of maternal FM acquisition. Efforts to synchronize protocols are necessary to allow seamless comparison of data to advance the understanding of maternal body composition changes that contribute to pregnancy-related complications.

Maternal lipids in pregnancy are associated with increased offspring cortisol reactivity in childhood

Prenatal programming of hypothalamic-pituitary-adrenal (HPA) axis activity has long term implications for offspring health. Biological mechanisms underlying programming of the offspring HPA axis are poorly understood. We hypothesised that altered maternal metabolism including higher maternal obesity, glucose and lipids are novel programming factors for altered offspring HPA axis activity. Salivary cortisol levels were measured in 54 children aged 3-5 years under experimental conditions (before and after a delay of self-gratification test). Associations of child cortisol responses with maternal obesity in early pregnancy and with fasting glucose, triglycerides, HDL and total cholesterol measured in each pregnancy trimester were tested. Higher levels of maternal triglycerides and total cholesterol throughout pregnancy were associated with increased offspring cortisol reactivity. The associations were independent of maternal obesity and other confounders, suggesting that exposure to maternal lipids could be a biological mechanism of in utero programming of the offspring's HPA axis.

Programming of infant neurodevelopment by maternal obesity: potential role of maternal inflammation and insulin resistance

BACKGROUND AND OBJECTIVES

Recent studies show that maternal obesity is associated with impaired offspring neurodevelopmental outcomes. The mechanism underlying the association is unclear. However, there is evidence to suggest a role for intra-uterine exposure to inflammation and insulin resistance (IR). We aimed to determine if maternal IR and inflammation were associated to fetal neurodevelopment as indicated by fetal heart rate variability (HRV), an index of fetal cardiac autonomic nervous system development.

METHODS AND STUDY DESIGN

A total of 44 healthy maternal-fetal pairs (maternal pre-pregnancy BMI distribution: n=20 normal weight, 8 overweight, 16 obese) were analyzed. We assessed maternal inflammation (plasma IL-6 and TNF-α) and IR (HOMA index). Fetal HRV, a proxy for fetal neurodevelopment, was assessed using fetal magnetocardiogram at the 36th week of pregnancy. The relationships between maternal inflammation and IR with fetal HRV (SD1 and SD2) were estimated individually by Pearson bivariate correlations.

RESULTS

No correlations were observed between the fetal HRV components with maternal HOMA-IR and maternal plasma levels of IL-6 and TNF-α (all p<0.05). However, the negative association between maternal TNF-α level and fetal SD2 approached significance (correlation coefficient=-0.29, 95% confidence interval=-0.62,-0.03, p=0.07).

CONCLUSION

Maternal IR and inflammation during pregnancy were not associated with fetal cardiac autonomic nervous system development. Further studies with a larger sample size and more maternal inflammatory indicators are needed to explore these relationships.

Influence of maternal obesity on the long-term health of offspring

In addition to immediate implications for pregnancy complications, increasing evidence implicates maternal obesity as a major determinant of offspring health during childhood and later adult life. Observational studies provide evidence for effects of maternal obesity on her offspring's risks of obesity, coronary heart disease, stroke, type 2 diabetes, and asthma. Maternal obesity could also lead to poorer cognitive performance and increased risk of neurodevelopmental disorders, including cerebral palsy. Preliminary evidence suggests potential implications for immune and infectious-disease-related outcomes. Insights from experimental studies support causal effects of maternal obesity on offspring outcomes, which are mediated at least partly through changes in epigenetic processes, such as alterations in DNA methylation, and perhaps through alterations in the gut microbiome. Although the offspring of obese women who lose weight before pregnancy have a reduced risk of obesity, few controlled intervention studies have been done in which maternal obesity is reversed and the consequences for offspring have been examined. Because the long-term effects of maternal obesity could have profound public health implications, there is an urgent need for studies on causality, underlying mechanisms, and effective interventions to reverse the epidemic of obesity in women of childbearing age and to mitigate consequences for offspring.

Decreased maternal hypothalamic-pituitary-adrenal axis activity in very severely obese pregnancy: Associations with birthweight and gestation at delivery

BACKGROUND

The maternal hypothalamic-pituitary-adrenal-axis (HPAA) undergoes dramatic activation during pregnancy. Increased cortisol and corticotrophin-releasing-hormone (CRH) associate with low birthweight and preterm labor. In non-pregnant obesity, the HPAA is activated but circulating cortisol levels are normal or lower than in lean women. We hypothesized that maternal cortisol levels would be lower in obese pregnancy, and would associate with increased fetal size and length of gestation.

METHOD

Fasting serum cortisol was measured at 16, 28 and 36 weeks gestation and at 3-6 months postpartum in 276 severely obese and 135 lean women. In a subset of obese (n=20) and lean (n=20) we measured CRH, hormones that regulate bioavailable cortisol (corticosteroid-binding-globulin, estradiol, estriol, and progesterone). Urinary glucocorticoid metabolites were measured in pregnant (obese n=6, lean n=5) and non-pregnant (obese n=7, lean n=7) subjects.

RESULTS

Maternal cortisol and HPAA hormones were lower in obese pregnancy. Total urinary glucocorticoid metabolites increased significantly in lean pregnancy, but not in obese. Lower maternal cortisol in obese tended to be associated with increased birthweight (r=-0.13, p=0.066). In obese, CRH at 28 weeks correlated inversely with gestational length (r=-0.49, p=0.04), and independently predicted gestational length after adjustment for confounding factors (mean decrease in CRH of -0.25 pmol/L (95% CI -0.45 to -0.043 pmol/L) per/day increase in gestation).

CONCLUSION

In obese pregnancy, lower maternal cortisol without an increase in urinary glucocorticoid clearance may indicate a lesser activation of the HPAA than in lean pregnancy. This may offer a novel mechanism underlying increased birthweight and longer gestation in obese pregnancy.

Health Behaviours during Pregnancy in Women with Very Severe Obesity

The health behaviours of pregnant women with very severe obesity are not known, though these women are at high risk of pregnancy complications. We carried out a prospective case-control study including 148 very severely obese (BMI >40 kg/m²) and 93 lean (BMI <25 kg/m²) pregnant women. Diet, physical activity, smoking, alcohol and folic acid consumption were assessed by questionnaire in early and late (16 and 28 weeks gestation) pregnancy. Circulating levels of iron, vitamin B12 and folate and other essential trace elements and minerals were measured in a subset at each time point. The findings biochemically confirmed that very severely obese women consumed diets that were energy-rich but poor in essential micronutrients. A third of all women met physical activity recommendations for pregnancy. A third of very severely obese women and two thirds of lean women took folic acid supplements prior to pregnancy. Very severely obese women were more likely to smoke but less likely to drink alcohol than lean women (all p < 0.05). Women with very severe obesity have low self-reported intakes and circulating levels of essential micronutrients in pregnancy and few follow current recommendations for pregnancy nutrition and lifestyle. These high-risk women represent a group to target for education about health behaviours prior to and during pregnancy.