Metabolite Changes in Maternal and Fetal Plasma Following Spontaneous Labour at Term in Humans Using Untargeted Metabolomics Analysis: A Pilot Study

Neurodevelopment and Metabolism in the Maternal-Placental-Fetal Unit

Importance

Disturbances in maternal, placental, and fetal metabolism are associated with developmental outcomes. Associations of maternal, placental, and fetal metabolism with subsequent neurodevelopmental outcomes in the child are understudied.

Objective

To investigate the metabolic associations within the maternal-placental-fetal unit and subsequent neurodevelopmental outcomes in younger siblings of children with autism spectrum disorder (ASD).

Design, Setting, and Participants

This cohort study was conducted within a subset of the Markers of Autism Risk in Babies, Learning Early Signs (MARBLES) cohort. MARBLES is a prospective birth cohort of younger siblings of children with ASD assessed for neurodevelopmental outcomes at approximately age 36 months. Participants in MARBLES were recruited through the UC Davis MIND Institute. This subset of the MARBLES cohort included younger siblings born between 2009 and 2015. Maternal third trimester serum, placental tissue, and umbilical cord serum samples were collected from participants. Only pregnancies with at least 2 of these sample types were included in this analysis. Data analysis was conducted from March 1, 2023, to March 15, 2024.

Exposures

Quantitative metabolomics analysis was conducted on maternal third trimester serum, as well as placental tissue and umbilical cord serum collected at delivery.

Main Outcomes and Measures

Using the Autism Diagnostic Observation Schedule and Mullen Scales of Early Learning, outcomes were classified as ASD, other nontypical development (non-TD), and typical development (TD).

Results

This analysis included 100 maternal serum samples, 141 placental samples, and 124 umbilical cord serum samples from 152 pregnancies (median [IQR] maternal age, 34.6 [30.8-38.3] years; median [IQR] gestational age, 39.0 [38.6-39.7] weeks; 87 [57.2%] male infants). There was no evidence that the maternal third trimester serum metabolome was significantly associated with the other metabolomes. The placental and cord serum metabolomes were highly correlated (first latent variate pair: R2 = 0.75; P < .001) and the variate scores for each tissue were significantly associated with reduced risk of non-TD (placenta: relative risk [RR], 0.13; 95% CI, 0.02-0.71; cord: RR, 0.13; 95% CI, 0.03-0.70) but not ASD (placenta: RR, 1.09; 95% CI, 0.42-2.81; cord: RR, 0.63; 95% CI, 0.23-1.73) compared with the TD reference group.

Conclusions and Relevance

In this cohort study of children with high familial risk of ASD, placental and cord serum metabolism at delivery were highly correlated. Furthermore, placental and cord serum metabolic profiles were associated with risk of non-TD.

Ceramides during Pregnancy and Obstetrical Adverse Outcomes

Ceramides are a group of sphingolipids located in the external plasma membrane layer and act as messengers in cellular pathways such as inflammatory processes and apoptosis. Plasma ceramides are biomarkers of cardiovascular disease, type 2 diabetes mellitus, Alzheimer's disease, various autoimmune conditions and cancer. During pregnancy, ceramides play an important role as stress mediators, especially during implantation, delivery and lactation. Based on the current literature, plasma ceramides could be potential biomarkers of obstetrical adverse outcomes, although their role in metabolic pathways under such conditions remains unclear. This review aims to present current studies that examine the role of ceramides during pregnancy and obstetrical adverse outcomes, such as pre-eclampsia, gestational diabetes mellitus and other complications.

The feto-placental metabolome of spontaneous labour is not reproduced following induction of labour

INTRODUCTION

The mechanism for human labour remains poorly understood, limiting our ability to manage complications including spontaneous preterm birth and induction of labour (IOL). The study of fetal signals poses specific challenges. Metabolomic analysis of maternal blood, the cord artery (CA), and cord vein (CV), allows simultaneous interrogation of multiple metabolic pathways associated with different modes of labour onset and birth.

METHODS

Global mass spectrometry metabolomics analysis was performed on serial samples collected from participants during pregnancy, in latent phase of labour, and following birth (CA, CV, and intervillous (IV) blood), from those who spontaneously laboured and birthed vaginally (SL group), had IOL and birthed vaginally (IOL group), or birthed via elective caesarean section (no labour; ECS group).

RESULTS

There were clear differences in fetal and maternal steroid, arachidonate and sphingosine pathways between the SL and IOL groups, despite similar uterine contractions and vaginal birth. The CA/CV ratio for key steroids of the IOL group were more alike the ECS group than the SL group, including progesterone (CA/CV ratio for: SL group=3.5; IOL group=0.5; and ECS group=0.5), and oestriol (CA/CV ratio for: SL group=4.3; IOL group=0.4; and for ECS group=0.2). There were no such changes in the maternal samples.

DISCUSSION

These findings indicate that IOL does not reproduce the pathways activated in spontaneous labour. The decreased placental progesterone production observed with spontaneous labour may represent a local intrauterine progesterone withdrawal, which, together with other signals, would activate parturition pathways involving arachidonate and sphingosine metabolism.

The newborn metabolome: associations with gestational diabetes, sex, gestation, birth mode, and birth weight

BACKGROUND

Pathways towards many adult-onset conditions begin early in life, even in utero. Maternal health in pregnancy influences this process, but little is known how it affects neonatal metabolism. We investigated associations between pregnancy and birth factors and cord blood metabolomic profile in a large, population-derived cohort.

METHODS

Metabolites were measured using nuclear magnetic resonance in maternal (28 weeks gestation) and cord serum from 912 mother-child pairs in the Barwon Infant Study pre-birth cohort. Associations between maternal (metabolites, age, BMI, smoking), pregnancy (pre-eclampsia, gestational diabetes (GDM)), and birth characteristics (delivery mode, gestational age, weight, infant sex) with 72 cord blood metabolites were examined by linear regression.

RESULTS

Delivery mode, sex, gestational age, and birth weight were associated with specific metabolite levels in cord blood, including amino acids, fatty acids, and cholesterols. GDM was associated with higher cord blood levels of acetoacetate and 3-hydroxybutyrate.

CONCLUSIONS

Neonatal factors, particularly delivery mode, were associated with many cord blood metabolite differences, including those implicated in later risk of cardiometabolic disease. Associations between GDM and higher offspring ketone levels at birth are consistent with maternal ketosis in diabetic pregnancies. Further work is needed to determine whether these neonatal metabolome differences associate with later health outcomes.

IMPACT

Variations in blood metabolomic profile have been linked to health status in adults and children, but corresponding data in neonates are scarce. We report evidence that pregnancy complications, mode of delivery, and offspring characteristics, including sex, are independently associated with a range of circulating metabolites at birth, including ketone bodies, amino acids, cholesterols, and inflammatory markers. Independent of birth weight, exposure to gestational diabetes is associated with higher cord blood ketone bodies and citrate. These findings suggest that pregnancy complications, mode of delivery, gestational age, and measures of growth influence metabolic pathways prior to birth, potentially impacting later health and development.

Functional changes in decidual mesenchymal stem/stromal cells are associated with spontaneous onset of labour

Ageing and parturition share common pathways, but their relationship remains poorly understood. Decidual cells undergo ageing as parturition approaches term, and these age-related changes may trigger labour. Mesenchymal stem/stromal cells (MSCs) are the predominant stem cell type in the decidua. Stem cell exhaustion is a hallmark of ageing, and thus ageing of decidual MSCs (DMSCs) may contribute to the functional changes in decidual tissue required for term spontaneous labour. Here, we determine whether DMSCs from patients undergoing spontaneous onset of labour (SOL-DMSCs) show evidence of ageing-related functional changes compared with those from patients not in labour (NIL-DMSCs), undergoing Caesarean section. Placentae were collected from term (37-40 weeks of gestation), SOL (n = 18) and NIL (n = 17) healthy patients. DMSCs were isolated from the decidua basalis that remained attached to the placenta after delivery. DMSCs displayed stem cell-like properties and were of maternal origin. Important cell properties and lipid profiles were assessed and compared between SOL- and NIL-DMSCs. SOL-DMSCs showed reduced proliferation and increased lipid peroxidation, migration, necrosis, mitochondrial apoptosis, IL-6 production and p38 MAPK levels compared with NIL-DMSCs (P < 0.05). SOL- and NIL-DMSCs also showed significant differences in lipid profiles in various phospholipids (phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine), sphingolipids (ceramide, sphingomyelin), triglycerides and acyl carnitine (P < 0.05). Overall, SOL-DMSCs had altered lipid profiles compared with NIL-DMSCs. In conclusion, SOL-DMSCs showed evidence of ageing-related reduced functionality, accumulation of cellular damage and changes in lipid profiles compared with NIL-DMSCs. These changes may be associated with term spontaneous labour.

Novel associations between parental and newborn cord blood metabolic profiles in the Norwegian Mother, Father and Child Cohort Study

BACKGROUND

More than one third of Norwegian women and men between 20 and 40 years of age have elevated cholesterol concentration. Parental metabolic health around conception or during pregnancy may affect the offspring's cardiovascular disease risk. Lipids are important for fetal development, but the determinants of cord blood lipids have scarcely been studied. We therefore aimed to describe the associations between maternal and paternal peri-pregnancy lipid and metabolic profile and newborn cord blood lipid and metabolic profile.

METHODS

This study is based on 710 mother-father-newborn trios from the Norwegian Mother, Father and Child Cohort Study (MoBa) and uses data from the Medical Birth Registry of Norway (MBRN). The sample included in this study consisted of parents with and without self-reported hypercholesterolemia the last 6 months before pregnancy and their partners and newborns. Sixty-four cord blood metabolites detected by nuclear magnetic resonance spectroscopy were analyzed by linear mixed model analyses. The false discovery rate procedure was used to correct for multiple testing.

RESULTS

Among mothers with hypercholesterolemia, maternal and newborn plasma high-density lipoprotein cholesterol, apolipoprotein A1, linoleic acid, docosahexaenoic acid, alanine, glutamine, isoleucine, leucine, valine, creatinine, and particle concentration of medium high-density lipoprotein were significantly positively associated (0.001 ≤ q ≤ 0.09). Among mothers without hypercholesterolemia, maternal and newborn linoleic acid, valine, tyrosine, citrate, creatinine, high-density lipoprotein size, and particle concentration of small high-density lipoprotein were significantly positively associated (0.02 ≤ q ≤ 0.08). Among fathers with hypercholesterolemia, paternal and newborn ratio of apolipoprotein B to apolipoprotein A1 were significantly positively associated (q = 0.04). Among fathers without hypercholesterolemia, no significant associations were found between paternal and newborn metabolites. Sex differences were found for many cord blood lipids.

CONCLUSIONS

Maternal and paternal metabolites and newborn sex were associated with several cord blood metabolites. This may potentially affect the offspring's long-term cardiovascular disease risk.