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

Early pregnancy serum PFAS are associated with alterations in the maternal lipidome

Per- and polyfluoroalkyl substances (PFAS) have been detected in the blood of humans and animals worldwide. Exposure to some PFAS are associated with multiple adverse pregnancy outcomes. Existing literature has identified a strong association with PFAS exposure and metabolic dysfunction in humans, including modification of lipid metabolism. Using a subset of the Michigan Mother-Infant Pairs cohort (n = 95), this study investigated associations between first trimester plasma levels of PFAS and maternal lipids and metabolites in the first trimester (T1), at the time of delivery (T3), and in the infant cord blood (CB) using untargeted shotgun lipidomics and metabolomics. Identifying PFAS-induced alterations in the maternal lipid- or metabolome at specific timepoints may help elucidate windows of susceptibility to adverse pregnancy outcomes. Out of 9 PFAS measured, 7 were detected in at least 20% of samples and were used for further analyses. PFOS and PFHxS were measured at the highest concentrations with medians of 5.76 ng/mL and 3.33 ng/mL, respectively. PFOA, PFNA, and PFDA had lower measured values with medians of <1.2 ng/mL. PFHxS concentrations were positively associated with monounsaturated sphingomyelins (SMs) in T1 maternal plasma in adjusted models, determined by an adjusted p-value (q) < 0.1. PFHxS was positively associated with saturated and polyunsaturated SMs and inversely associated with saturated diacylglycerols in T1. Following metabolite-specific analysis, two mono-unsaturated diacylglycerols with carbon chain lengths of 32 and 35 were inversely associated with PFHxS in T1. In T3, only the association between PFHxS and SMs remained, but was attenuated. In addition, PFDA was associated with an increase in polyunsaturated plasmenyl-phosphatidylethanolamines in T3. No associations were identified between PFAS and infant cord blood lipids. Continued research into PFAS associated disruptions in lipid metabolism at sensitive stages of gestation may provide insight into the mechanisms that lead to adverse birth and pregnancy outcomes.

Introduction to the Proteomic Analysis of Placentas with Fetal Growth Restriction and Impaired Lipid Metabolism

Fetal growth restriction (FGR) is a disorder defined as the failure of a fetus to achieve its full biological development potential due to decreased placental function, which can be attributed to a range of reasons. FGR is linked to negative health outcomes during the perinatal period, including increased morbidity and mortality. Long-term health problems, such as impaired neurological and cognitive development, as well as cardiovascular and endocrine diseases, have also been found in adulthood. Aspirin administered prophylactically to high-risk women can effectively prevent FGR. FGR pregnancy care comprises several steps, including the weekly assessment of several blood vessels using Doppler measurements, amniotic fluid index (AFI), estimated fetal weight (EFW), cardiotocography (CTG), as well as delivery by 37 weeks. Pregnancy is a complex condition characterized by metabolic adjustments that guarantee a consistent provision of vital metabolites allowing the fetus to grow and develop. The lipoprotein lipid physiology during pregnancy has significant consequences for both the fetus and baby, and for the mother. In the course of a typical pregnancy, cholesterol levels increase by roughly 50%, LDL-C (low-density lipoprotein cholesterol) levels by 30-40%, HDL-C by 25% (high-density lipoprotein cholesterol). Typically, there is also a 2- to 3-fold increase in triglycerides. Low maternal blood cholesterol levels during pregnancy are linked to a decrease in birth weight and an increased occurrence of microcephaly. FGR impacts the placenta during pregnancy, resulting in alterations in lipid metabolism. Research has been undertaken to distinguish variations in protein expression between normal placentas and those impacted by FGR. This can aid in comprehending the fundamental pathogenic mechanisms of FGR and perhaps pave the way for the creation of novel diagnostic and treatment methods. Commonly employed approaches for detecting and analyzing variations in placental proteomes include mass spectrometry, bioinformatic analysis, and various proteomic techniques.

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

Background

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

Methods

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

Results

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

Conclusion

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

COVID-19 Infection during Pregnancy: Disruptions in Lipid Metabolism and Implications for Newborn Health

The COVID-19 pandemic has raised questions about indirect impact in pregnant women on the development of their future children. Investigating the characteristics of lipid metabolism in the "mother-placenta-fetus" system can give information about the pathophysiology of COVID-19 infection during pregnancy. A total of 234 women were included in study. Maternal plasma, cord blood, and amniotic fluid lipidome were analyzed using HPLC-MS/MS. Differences in lipid profile were searched by Mann-Whitney and Kruskall-Wallis test, and diagnostic model based on logistic regression were built by AIC. Elevated levels of lysophospholipids, triglycerides, sphingomyelins, and oxidized lipids were registered in patients' maternal and cord plasma after COVID-19 infection. An increase in maternal plasma sphingomyelins and oxidized lipids was observed in cases of infection during the second trimester. In amniotic fluid, compared to the control group, nine lipids were reduced and six were elevated. Levels of phosphoglycerides, lysophosphoglycerides, and phosphatidylinositols decreased during infection in the second and third trimesters of pregnancy. A health diagnostic model for newborns based on maternal plasma was developed for each group and exhibited good diagnostic value (AUC > 0.85). Maternal and cord plasma's lipidome changes during delivery, which are associated with COVID-19 infection during pregnancy, are synergistic. The most significant disturbances occur with infections in the second trimester of pregnancy.

The Importance of Metabolic and Environmental Factors in the Occurrence of Oxidative Stress during Pregnancy

Metabolic changes in pregnant women begin in the first weeks after conception under the influence of placental hormones that affect the metabolism of all nutrients. An increased concentration of total lipids accompanies pregnancy and an increased accumulation of triglycerides in low-density lipoproteins (LDL) particles. Lipids in small dense LDL particles are more susceptible to oxidative modification than normal-density LDL particles. Unlike LDL high-density lipoproteins (HDL), lipoprotein particles have an atheroprotective role in lipid metabolism. The very growth of the fetus depends on the nutrition of both parents, so obesity is not only in the mother but also in the father. Nutritional programming of the offspring occurs through changes in lipid metabolism and leads to an increased risk for cardiometabolic diseases. Pregnancy is accompanied by an increased need for oxygen in the mitochondria of the placenta and a tendency to develop oxidative stress. Oxidative stress represents a disturbance in the balance of oxidation-reduction processes in the body that occurs due to the excessive production of free oxygen radicals that cellular homeostatic mechanisms are unable to neutralize. When the balance with the antioxidant system is disturbed, which happens when free oxygen radicals are in high concentrations, serious damage to biological molecules occurs, resulting in a series of pathophysiological and pathological changes, including cell death. Therefore, oxidative stress plays a significant role in the pathogenesis of many complications that can occur during pregnancy. The oxidative status of pregnant women is also influenced by socioeconomic living conditions, lifestyle habits, diet, smoking, and exposure to environmental air pollution. During a healthy pregnancy, the altered lipid profile and oxidative stress create an increased risk for premature birth and pregnancy-related diseases, and a predisposition to adult diseases.

Developmental programming: Preconceptional and gestational exposure of sheep to a real-life environmental chemical mixture alters maternal metabolome in a fetal sex-specific manner

BACKGROUND

Everyday, humans are exposed to a mixture of environmental chemicals some of which have endocrine and/or metabolism disrupting actions which may contribute to non-communicable diseases. The adverse health impacts of real-world chemical exposure, characterized by chronic low doses of a mixture of chemicals, are only recently emerging. Biosolids derived from human waste represent the environmental chemical mixtures humans are exposed to in real life. Prior studies in sheep have shown aberrant reproductive and metabolic phenotypes in offspring after maternal biosolids exposure.

OBJECTIVE

To determine if exposure to biosolids perturbs the maternal metabolic milieu of pregnant ewes, in a fetal sex-specific manner.

METHODS

Ewes were grazed on inorganic fertilizer (Control) or biosolids-treated pastures (BTP) from before mating and throughout gestation. Plasma from pregnant ewes (Control n = 15, BTP n = 15) obtained mid-gestation were analyzed by untargeted metabolomics. Metabolites were identified using Agilent MassHunter. Multivariate analyses were done using MetaboAnalyst 5.0 and confirmed using SIMCA.

RESULTS

Univariate and multivariate analysis of 2301 annotated metabolites identified 193 differentially abundant metabolites (DM) between control and BTP sheep. The DM primarily belonged to the super-class of lipids and organic acids. 15-HeTrE, oleamide, methionine, CAR(3:0(OH)) and pyroglutamic acid were the top DM and have been implicated in the regulation of fetal growth and development. Fetal sex further exacerbated differences in metabolite profiles in the BTP group. The organic acids class of metabolites was abundant in animals with male fetuses. Prenol lipid, sphingolipid, glycerolipid, alkaloid, polyketide and benzenoid classes showed fetal sex-specific responses to biosolids.

DISCUSSION

Our study illustrates that exposure to biosolids significantly alters the maternal metabolome in a fetal sex-specific manner. The altered metabolite profile indicates perturbations to fatty acid, arginine, branched chain amino acid and one‑carbon metabolism. These factors are consistent with, and likely contribute to, the adverse phenotypic outcomes reported in the offspring.

Educational attainment and offspring birth weight: A bidirectional Mendelian randomization study

Background: The association between educational attainment (EA) and offspring birth weight (BW) has been reported by several traditional epidemiological studies. However, evidence for this association tends to be mixed and confounded. This study aimed to investigate the causal association between EA of parents and offspring BW. Methods: Here, we carried out a two-sample bidirectional Mendelian randomization (MR) analysis to examine the causal association between EA of males (n = 131,695) and females (n = 162,028) and offspring BW using genetic instruments. Summary statistics of EA associated single nucleotide polymorphisms (SNPs) were extracted from a GWAS incorporating 293,723 individuals of European descent performed by the Social Science Genetic Association Consortium (SSGAC), and the effects of these SNPs on offspring BW were estimated using a GWAS meta-analysis of 86,577 participants of European descent from 25 studies. Univariable MR analyses were conducted using the inverse-variance weighted (IVW) method and four other methods. Further sensitivity analyses were carried out to test the viability of the results. Multivariable MR was used to examine the confounders between the exposure and outcome. Results: The result shows evidence that the offspring BW is positively causally affected by female EA. Each one standard deviation (SD) increase in female EA was associated with 0.24 SD higher of offspring BW (95% confidence interval [CI], 0.10 to 0.37, p < 0.001 for the IVW method). Similarly, change in offspring BW was 0.21 SD (95% CI: 0.07 to 0.34, p = 2.82 × 10-3) per one SD higher in male EA. No causal effect of BW on EA was found by any of the five methods. The causal association between female EA and offspring BW maintained after adjusting for alcoholic drinks per week and BMI. The effect of male EA on offspring BW was attenuated when we adjusted for BMI and alcoholic drinks per week using multivariable MR analysis. Conclusion: Our study indicated that female EA is positively causally associated with offspring BW. The association between male EA and offspring BW may be confounded by alcoholic drinks per week and BMI.