Placental Responses to Changes in the Maternal Environment Determine Fetal Growth

Effects of semen inflammation on embryo implantation, placentation, pregnancy outcomes and offspring health

This review explores the critical role of semen inflammation in sperm quality, embryo implantation, placentation, and its broader implications on reproductive health. Chronic inflammation of the male genital tract has been increasingly recognized as a significant factor contributing to infertility. This inflammation not only impairs semen quality but also disrupts the intricate immune cross-talk between the male and female genital tracts, which is essential for successful implantation, placentation and pregnancy. The review synthesizes existing research on the mechanisms by which inflammatory mediators in semen influence the female immune environment, leading to altered uterine receptivity, placental formation, and embryo implantation. Furthermore, the impact of these disruptions on the health and development of the offspring is discussed, highlighting the transgenerational effects of male genital tract inflammation. Through an examination of both animal models and human studies, this review underscores the need for a deeper understanding of the immune interactions in reproductive biology and the potential for novel therapeutic interventions aimed at mitigating the adverse outcomes associated with semen inflammation.

Timing of antenatal corticosteroid exposure and its association with childhood mental disorders in early- and full-term births: A population-based cohort study

Although the administration of antenatal corticosteroids (ACS) is generally recognized as cost-effective and beneficial, recent studies have indicated potential long-term adverse effects on neurodevelopment, particularly for term-born infants. However, limited research has explored the association between the timing of ACS exposure, gestational age (GA) at birth, and their potential implications for mental and behavioral outcomes in offspring compared to non-exposed infants. This study aimed to examine the association between the timing of antenatal corticosteroid (ACS) exposure for threatened preterm labor and childhood mental disorders among early-term and full-term births. All eligible term infants born between 2010 to 2014 were included in this nationwide study and followed until the end of 2021. The primary outcome was any childhood mentaldisorders, with secondary outcomes being attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and developmental delay (DD). Compared to unexposed infants, ACS exposure before 34 weeks of GA increased the risk of developing mental behavior disorders. Exposure to ACS before 34 weeks was significantly associated with an increased risk of ADHD and DD; however, this association was observed only in early-term births but not in those born at full-term.

CONCLUSION

Our finding suggests a need for further investigation into the influence of GA at birth on these disorders and supports that the risk of childhood mental disorders in term infants varied among different ACS exposure timing.

WHAT IS KNOWN

• While administration of antenatal corticosteroids (ACS) for preterm birth threats is widely acknowledged as both cost-effective and beneficial, recent studies have raised concerns about potential long-term adverse effects on neurodevelopment, particularly in term-born infants. • Previous studies have found that early-term birth is associated with lower intelligence, ADHD, and poorer school performance compared to full-term birth.

WHAT IS NEW

• There is an interaction between the timing of ACS treatment and gestational age at birth with respect to the likelihood of neurodevelopmental outcomes in term-born infants. • Exposure to ACS before 34 weeks is associated with an increased risk of any childhood mental disorders, specifically ADHD and DD, among early-term births, whereas this association was not observed in infants who reached full-term gestation.

Evaluating Offspring After Pregnancy-Associated Cancer: A Systematic Review of Neonatal Outcomes

Background/Objectives: Pregnancy-associated cancer (PAC) presents significant challenges for maternal and neonatal health, and yet its impact on neonatal outcomes remains poorly understood. This systematic review aims to evaluate the neonatal risks associated with PAC. Methods: A systematic search of PubMed, Embase, Scopus, and other databases was conducted up to 1 November 2024, identifying observational studies and randomized controlled trials assessing neonatal outcomes in pregnancies affected by PAC. Outcomes included preterm birth, low birthweight, macrosomia, small and large for gestational age, low Apgar score, congenital anomalies, and neonatal mortality. Results: Eleven high-quality studies encompassing over 46 million births, including 9953 PAC-affected pregnancies, were reviewed. PAC significantly increased the risks of preterm birth (adjusted ORs ranging from 1.48 to 6.34) and low birthweight (adjusted ORs up to 5.5). Other adverse outcomes included low Apgar scores and neonatal mortality, primarily linked to prematurity. Cancer type and treatment timing influenced these outcomes, with gynecological and breast cancers posing higher risks. Conclusions: Neonates of mothers with PAC face increased risks of adverse outcomes, underscoring the importance of tailored, multidisciplinary management. Further prospective studies are needed to clarify the impacts of specific cancer treatments during pregnancy.

Metabolomic profiles of preterm small-for-gestational age infants

We aimed to characterize the metabolomic profiles in preterm small-for-gestational age (SGA) infants using cord blood. We conducted a gestational age (GA)-matched case-control study that included 30 preterm infants who were categorized into two groups: SGA infants, with a birth weight (BW) < 10th percentile for GA (n = 15) and non-SGA infants, with BW ≥ 10th percentile for GA (n = 15). SGA infants with chromosomal or genetic abnormalities were excluded. At birth, the umbilicus was double-clamped, and the cord blood was sampled from the umbilical vein. Metabolomic analyses were performed using capillary electrophoresis time-of-flight mass spectrometry. The median GA at birth was not significantly different between the two groups [SGA, 32 (26-36) weeks; non-SGA, 32 (25-35) weeks; p = 0.661)]. Of the 255 metabolites analyzed, 19 (7.5%) showed significant differences between SGA and non-SGA infants. There were significant reductions in the carnosine, hypotaurine, and S-methylcysteine levels in SGA infants as compared to non-SGA infants (p < 0.05). Carnosine was correlated with gestational age, BMI before pregnancy, body weight gain during pregnancy (p = 0.002, p = 0.023, and p = 0.020, respectively). In conclusion, preterm SGA infants have low levels of cord blood antioxidative- and antiglycation-related metabolites, making them vulnerable to oxidative stress.

Prenatal exposure to per- and polyfluoroalkyl substances, fetoplacental hemodynamics, and fetal growth

INTRODUCTION

The impact of legacy per- and polyfluoroalkyl substances (PFAS) on fetal growth has been well studied, but assessments of next-generation PFAS and PFAS mixtures are sparse and the potential role of fetoplacental hemodynamics has not been studied. We aimed to evaluate associations between prenatal PFAS exposure and fetal growth and fetoplacental hemodynamics.

METHODS

We included 747 pregnant women from the BiSC birth cohort (Barcelona, Spain (2018-2021)). Twenty-three PFAS were measured at 32 weeks of pregnancy in maternal plasma, of which 13 were present above detectable levels. Fetal growth was measured by ultrasound, as estimated fetal weight at 32 and 37 weeks of gestation, and weight at birth. Doppler ultrasound measurements for uterine (UtA), umbilical (UmA), and middle cerebral artery (MCA) pulsatility indices (PI), as well as the cerebroplacental ratio (CPR - ratio MCA to UmA), were obtained at 32 weeks to assess fetoplacental hemodynamics. We applied linear mixed effects models to assess the association between singular PFAS and longitudinal fetal growth and PI, and Bayesian Weighted Quantile Sum models to evaluate associations between the PFAS mixture and the aforementioned outcomes, controlled for the relevant covariates.

RESULTS

Single PFAS and the mixture tended to be associated with reduced fetal growth and CPR PI, but few associations reached statistical significance. Legacy PFAS PFOS, PFHpA, and PFDoDa were associated with statistically significant decreases in fetal weight z-score of 0.13 (95%CI (-0.22, -0.04), 0.06 (-0.10, 0.01), and 0.05 (-0.10, 0.00), respectively, per doubling of concentration. The PFAS mixture was associated with a non-statistically significant 0.09 decrease in birth weight z-score (95%CI -0.22, 0.04) per quartile increase.

CONCLUSION

This study suggests that legacy PFAS may be associated with reduced fetal growth, but associations for next generation PFAS and for the PFAS mixture were less conclusive. Associations between PFAS and fetoplacental hemodynamics warrant further investigation.

Effects of Maternal Dyslipidemia on Maternal and Perinatal Outcomes in Enugu, Southeast Nigeria: A Prospective Cohort Study

BACKGROUND

Maternal dyslipidemia is one of the consistent metabolic changes during pregnancy. There is a controversy as to whether maternal lipid disturbances in early pregnancy are associated with adverse maternal and perinatal outcome.

AIM

To determine the effects of maternal dyslipidemia on maternal and perinatal outcomes.

METHODS

A prospective observational cohort study of eligible pregnant women attending antenatal clinic (ANC) at two tertiary hospitals in Southeast Nigeria. The attendees blood samples were collected for lipid profile analysis and those who met the criteria for dyslipidemia constituted the study (exposed) group, while those with normal lipid levels were the control (unexposed group). Both groups were followed up throughout pregnancy and in labor to determine the pregnancy and perinatal outcomes.

RESULTS

Compared with pregnant women with normal lipid profile, those with dyslipidemia were at higher risk of low birth weight (LBW) (RR: 9.40, CI 95%: 1.3-70.2, P = 0.005), intrauterine fetal death (IUFD) (RR: 5.98; 95% CI: 0.8-46.9; P = 0.04), still birth (RR: 6.84, CI 95%: 8.9-52.7, P = 0.03), and birth asphyxia (RR: 10.26, CI 95%:1.4-76.0, P = 0.003).

CONCLUSION

Maternal dyslipidemia is associated with some adverse perinatal outcomes such as LBW, IUFD, still birth, and birth asphyxia. These findings would guide in the care of pregnant women with dyslipidemia.

From Mother to Child: Epigenetic Signatures of Hyperglycemia and Obesity during Pregnancy

BACKGROUND

In utero exposure to maternal hyperglycemia and obesity can trigger detrimental effects in the newborn through epigenetic programming. We aimed to assess the DNA methylation levels in the promoters of MC4R and LPL genes from maternal blood, placenta, and buccal swab samples collected in children born to mothers with and without obesity and Gestational Diabetes Mellitus (GDM).

METHODS

A total of 101 Caucasian mother-infant pairs were included in this study. Sociodemographic characteristics, clinical parameters, physical activity, and adherence to the Mediterranean diet were evaluated in the third trimester of pregnancy. Clinical parameters of the newborns were recorded at birth.

RESULTS

A negative relationship between MC4R DNA methylation on the fetal side of the GDM placenta and birth weight (r = -0.630, p = 0.011) of newborns was found. MC4R DNA methylation level was lower in newborns of GDM women (CpG1: 2.8% ± 3.0%, CpG2: 3.8% ± 3.3%) as compared to those of mothers without GDM (CpG1: 6.9% ± 6.2%, CpG2: 6.8% ± 5.6%; p < 0.001 and p = 0.0033, respectively), and it was negatively correlated with weight (r = -0.229; p = 0.035), head circumference (r = -0.236; p = 0.030), and length (r = -0.240; p = 0.027) at birth. LPL DNA methylation was higher on the fetal side of the placenta in obese patients as compared to normal-weight patients (66.0% ± 14.4% vs. 55.7% ± 15.2%, p = 0.037), and it was associated with maternal total cholesterol (r = 0.770, p = 0.015) and LDL-c (r = 0.783, p = 0.012).

CONCLUSIONS

These results support the role of maternal MC4R and LPL methylation in fetal programming and in the future metabolic health of children.

Association between serum branched chain amino acids, mammalian target of rapamycin levels and the risk of gestational diabetes mellitus: a 1:1 matched case control study

BACKGROUND

To investigate the association between serum branched chain amino acids (BCAAs), mammalian target of rapamycin (mTOR) levels and the risk of gestational diabetes mellitus (GDM) in pregnant women.

METHODS

1:1 matched case-control study was conducted including 66 GDM patients and 66 matched healthy pregnant women (± 3 years) in 2019, in China. Fasting bloods of pregnant women were collected in pregnancy at 24 ~ 28 weeks gestation. And the serum levels of valine (Val), leucine (Leu), isoleucine (Ile) and mTOR were determined. Conditional logistic regressions models were used to estimate the associations of BCAAs and mTOR concentrations with the risk of GDM.

RESULTS

Concentrations of serum Val and mTOR in cases were significantly higher than that in controls (P < 0.05). After adjusted for the confounded factors, both the second tertile and the third tertile of mTOR increased the risk of GDM (OR = 11.771, 95%CI: 3.949-35.083; OR = 4.869 95%CI: 1.742-13.611, respectively) compared to the first tertile of mTOR. However, the second tertile of serum Val (OR = 0.377, 95%CI:0.149-0.954) and the second tertile of serum Leu (OR = 0.322, 95%CI: 0.129-0.811) decreased the risk of GDM compared to the first tertile of serum Val and Leu, respectively. The restricted cubic spline indicated a significant nonlinear association between the serum levels of mTOR and the risk of GDM (P values for non-linearity = 0.0058).

CONCLUSION

We confirmed the association of higher mTOR with the increased risk of GDM in pregnant women. Pregnant women who were in the certain range level of Val and Leu were at lower risk of GDM. Our findings provided epidemiological evidence for the relation of serum BCAAs and mTOR with risk of GDM.

Placental pathology and fetal growth outcomes in pregnancies complicated by maternal obesity

BACKGROUND

The rising prevalence of maternal obesity presents a significant health concern because of the possible implications for obstetric complications and neonatal outcomes. Understanding the impact of obesity on placental structure and function as well as fetal growth and infant outcomes is important to improve the care of these potentially high-risk pregnancies. This study aimed to determine the effect of elevated maternal BMI on histopathologic patterns of placental injury and its consequences on fetal growth.

METHODS

Data were collected from an ongoing cohort of maternal-infant dyads in the UCSD Obstetric Registry spanning 2011-2020. Maternal characteristics, including BMI, hypertensive disease and diabetes, placental gross and histopathology, and infant characteristics, including sex and birthweight, were recorded and analyzed. ANOVA and chi-square tests were used in initial analyses, followed by log-binomial and linear regression models adjusted for relevant confounders to determine associations between maternal BMI, specific patterns of placental injury, and infant birthweight percentiles.

RESULTS

Among 1366 maternal-infant dyads, placentas from mothers with overweight and obesity were heavier and demonstrated higher adjusted relative risks of chronic villitis (CV), decidual vasculopathy, intervillous thrombosis, and normoblastemia. Placental efficiency, determined by fetal-placental weight ratio, was decreased with increasing BMI. Maternal obesity was associated with higher rates of preterm birth and higher birthweight percentiles. Multiple placental lesions, including maternal (MVM) and fetal vascular malperfusion (FVM), exhibited significant effects on birthweight percentiles; however, only MVM showed a differential effect based on maternal obesity.

CONCLUSIONS

Presence of obesity in pregnancy is associated with increased rates of placental patterns of injury, decreased placental efficiency, and increased birthweight percentiles. While placental lesions, such as CV, have the potential to negatively impact fetal growth, the resulting birthweight percentiles demonstrate a more complex relationship between maternal obesity and fetal growth, that likely involves placental and fetal adaptation to the altered in utero environment.

Fetal growth restriction induced by maternal gal-3 deficiency is associated with altered gut-placenta axis

Adverse intrauterine conditions may cause fetal growth restriction (FGR), a pregnancy complication frequently linked to perinatal morbidity and mortality. Although many studies have focused on FGR, the pathophysiological processes underlying this disorder are complex and incompletely understood. We have recently determined that galectin-3 (gal-3), a β-galactoside-binding protein, regulates pregnancy-associated processes, including uterine receptibility, maternal vascular adaptation and placentation. Because gal-3 is expressed at both sides of the maternal-fetal interface, we unraveled the contribution of maternal- and paternal-derived gal-3 on fetal-placental development in the prenatal window and its effects on the post-natal period. Deficiency of maternal gal-3 induced maternal gut microbiome dysbiosis, resulting in a sex-specific fetal growth restriction mainly observed in female fetuses and offspring. In addition, poor placental metabolic adaptions (characterized by decreased trophoblast glycogen content and insulin-like growth factor 2 (Igf2) gene hypomethylation) were only associated with a lack of maternal-derived gal-3. Paternal gal-3 deficiency caused compromised vascularization in the placental labyrinth without affecting fetal growth trajectory. Thus, maternal-derived gal-3 may play a key role in fetal-placental development through the gut-placenta axis.

Comprehensive insights into the understanding of hypoxia in ameloblastoma

Hypoxia is characterized by a disparity between supply and demand of oxygen. The association between hypoxia and head and neck tumors is a topic of significant interest. Tumors frequently encounter areas with inadequate oxygen supply, resulting in a hypoxic microenvironment. Ameloblastoma is one of the most common benign odontogenic tumors of the maxillofacial region. It is a slow-growing but locally invasive tumor with a high recurrence rate. The literature has demonstrated the correlation between hypoxia and ameloblastoma, revealing a discernible link between the heightened expression of hypoxic markers in low oxygen conditions. This association is intricately tied to the tumoral potential for invasion, progression, and malignant transformation. Hypoxia profoundly influences the molecular and cellular landscape within ameloblastic lesions. The present review sheds light on the mechanisms, implications, and emerging perspectives in understanding this intriguing association to clarify the dynamic relationship between hypoxia and ameloblastoma.

Impact of Maternal-Fetal Environment on Outcomes Following the Hybrid Procedure in the Single Ventricle Population

Treatment of infants with hypoplastic left heart syndrome (HLHS) remains challenging, and those affected remain with significant risks for mortality and morbidity throughout their lifetimes. The maternal-fetal environment (MFE) has been shown to affect outcomes for infants with HLHS after the Norwood procedure. The hybrid procedure, comprised of both catheterization and surgical components, is a less invasive option for initial intervention compared to the Norwood procedure. It is unknown how the MFE impacts outcomes following the hybrid procedure. This is a single-center, retrospective study of infants born with HLHS who underwent hybrid palliation from January 2009 to August 2021. Predictor variables analyzed included fetal, maternal, and postnatal factors. The primary outcome was mortality prior to Stage II palliation. We studied a 144-subject cohort. There was a statistically significant difference in mortality prior to stage II palliation in infants with prematurity, small for gestational age, and aortic atresia subtype (p < 0.001, p = 0.009, and p = 0.008, respectively). There was no difference in mortality associated with maternal diabetes, hypertension, obesity, smoking or illicit drug use, or advanced maternal age. State and national area deprivation index scores were associated with increased risk of mortality in the entire cohort, such that infants born in areas with higher deprivation had a higher incidence of mortality. Several markers of an impaired MFE, including prematurity, small for gestational age, and higher deprivation index scores, are associated with mortality following hybrid palliation. Individual maternal comorbidities were not associated with higher mortality. The MFE may be a target for prenatal counseling and future interventions to improve pregnancy and neonatal outcomes in this population.

Prenatal exposure to multiple environmental chemicals and birth size

BACKGROUND

Epidemiological studies addressing the combined effects of exposure to chemical mixtures at different stages of pregnancy on birth size are scarce.

OBJECTIVE

To evaluate the association between prenatal exposure to chemical mixtures and birth size.

METHODS

Our previous study repeatedly measured the urinary concentrations of 34 chemical substances among 743 pregnant women and identified three distinct clusters of exposed population and six dominant principal components of exposed chemicals in each trimester. In this study, we assessed the associations of these exposure profiles with birth weight, birth length, and ponderal index using multivariable linear regression.

RESULTS

We found that compared with women in cluster 1 (lower urinary chemical concentrations), women in cluster 2 (higher urinary concentrations of metals, benzothiazole, benzotriazole, and some phenols), and women in cluster 3 (higher urinary concentrations of phthalates) were more likely to give birth to children with higher birth length [0.23 cm (95% CI: -0.03, 0.49); 0.29 cm (95%CI: 0.03, 0.54), respectively]. This association was observed only in 1st trimester. In addition, prenatal exposure to PC3 (higher benzophenones loading) was associated with reduced birth length across pregnancy [-0.07 cm (95% CI: -0.18, 0.03) in 1st and 2nd trimester; -0.13 cm (95% CI: -0.24, -0.03) in 3rd trimester]. Exposure to PC6 (higher thallium and BPA loading in 2nd trimester) was associated with increased birth length [0.15 cm (95% CI: 0.05, 0.26)]. Compared with other outcomes, associations of both clusters and PCs with birth length were stronger, and these associations were more pronounced in boys.

IMPACT STATEMENT

Exposure to multiple chemicals simultaneously, the actual exposure situation of pregnant women, was associated with birth size, indicating that chemical mixtures should be taken more seriously when studying the health effects of pollutants.

Hemostatic Status of Neonates with Perinatal Hypoxia, Studied via NATEM in Cord Blood Samples

BACKGROUND

Perinatal hypoxia may result in coagulation dysfunction. Diminished blood flow or oxygen to the fetus/neonate during the perinatal period can cause bone marrow and liver function impairment, leading to thrombocytopenia, impaired synthesis of clotting and fibrinolytic factors, and increased destruction of platelets in the small blood vessels. The goal of the present study was to evaluate the hemostatic status of newborns with perinatal hypoxia via the non-activated thromboelastometry (NATEM) assay in cord blood samples.

METHODS

134 hypoxic neonates born in our maternity unit over a 1.5-year period were enrolled in this observational cohort study, and 189 healthy neonates served as the control group. Participation in the study was voluntary and parents signed informed consent prior to recruitment. Demographic and clinical data were recorded on admission, and the NATEM method was performed on cord blood samples. The following NATEM values were evaluated: clotting time (CT), alpha angle (α-angle), clot formation time (CFT), clot amplitude at 5 and 10 min. (A5, A10), maximum clot firmness (MCF), clot lysis index at 60 min. after CT (LI60), and maximum clot elasticity (MCE). Statistical analysis was conducted utilizing the SAS for Windows 9.4 software platform.

RESULTS

Neonates with perinatal hypoxia exhibited decreased fibrinolytic potential in comparison to healthy neonates, as indicated by increased LI60, and this difference was statistically significant (LΙ60: 94 (92-96) Vs 93 (91-95), p value = 0.0001). There were no statistically significant differences noted among the remaining NATEM variables.

CONCLUSION

Our findings indicate decreased fibrinolytic potential in hypoxic neonates in comparison to healthy neonates, suggesting that NATEM could serve as an effective tool for promptly identifying hemostasis dysfunction in this group of neonates.

Sub-Optimal Paternal Diet at the Time of Mating Disrupts Maternal Adaptations to Pregnancy in the Late Gestation Mouse

Pregnancy represents a stage during which maternal physiology and homeostatic regulation undergo dramatic change and adaptation. The fundamental purpose of these adaptations is to ensure the survival of her offspring through adequate nutrient provision and an environment that is tolerant to the semi-allogenic foetus. While poor maternal diet during pregnancy is associated with perturbed maternal adaptations during pregnancy, the influence of paternal diet on maternal well-being is less clearly defined. We fed C57BL/6 male mice either a control (CD), low protein diet (LPD), a high fat/sugar Western diet (WD) or the LPD or WD supplemented with methyl donors (MD-LPD and MD-WD, respectively) for a minimum of 8 weeks prior to mating with C57BL/6 females. Mated females were culled at day 17 of gestation for the analysis of maternal metabolic, gut, cardiac and bone health. Paternal diet had minimal influences on maternal serum and hepatic metabolite levels or gut microbiota diversity. However, analysis of the maternal hepatic transcriptome revealed distinct profiles of differential gene expression in response to the diet of the father. Paternal LPD and MD-LPD resulted in differential expression of genes associated with lipid metabolism, transcription, ubiquitin conjugation and immunity in dams, while paternal WD and MD-WD modified the expression of genes associated with ubiquitin conjugation and cardiac morphology. Finally, we observed changes in maternal femur length, volume of trabecular bone, trabecular connectivity, volume of the cortical medullar cavity and thickness of the cortical bone in response to the father's diets. Our current study demonstrates that poor paternal diet at the time of mating can influence the patterns of maternal metabolism and gestation-associated adaptations to her physiology.

Placental Epigenome Impacts Fetal Development: Effects of Maternal Nutrients and Gut Microbiota

Evidence is emerging on the role of maternal diet, gut microbiota, and other lifestyle factors in establishing lifelong health and disease, which are determined by transgenerationally inherited epigenetic modifications. Understanding epigenetic mechanisms may help identify novel biomarkers for gestation-related exposure, burden, or disease risk. Such biomarkers are essential for developing tools for the early detection of risk factors and exposure levels. It is necessary to establish an exposure threshold due to nutrient deficiencies or other environmental factors that can result in clinically relevant epigenetic alterations that modulate disease risks in the fetus. This narrative review summarizes the latest updates on the roles of maternal nutrients (n-3 fatty acids, polyphenols, vitamins) and gut microbiota on the placental epigenome and its impacts on fetal brain development. This review unravels the potential roles of the functional epigenome for targeted intervention to ensure optimal fetal brain development and its performance in later life.

Gestational Age, Infection, and Suboptimal Maternal Prepregnancy BMI Independently Associate with Placental Histopathology in a Cohort of Pregnancies without Major Maternal Comorbidities

Background: The placenta undergoes morphological and functional adaptations to adverse exposures during pregnancy. The effects ofsuboptimal maternal body mass index (BMI), preterm birth, and infection on placental histopathological phenotypes are not yet well understood, despite the association between these conditions and poor offspring outcomes. We hypothesized that suboptimal maternal prepregnancy BMI and preterm birth (with and without infection) would associate with altered placental maturity and morphometry, and that altered placental maturity would associate with poor birth outcomes. Methods: Clinical data and human placentae were collected from 96 pregnancies where mothers were underweight, normal weight, overweight, or obese, without other major complications. Placental histopathological characteristics were scored by an anatomical pathologist. Associations between maternal BMI, placental pathology (immaturity and hypermaturity), placental morphometry, and infant outcomes were investigated for term and preterm births with and without infection. Results: Fetal capillary volumetric proportion was decreased, whereas the villous stromal volumetric proportion was increased in placentae from preterm pregnancies with chorioamnionitis compared to preterm placentae without chorioamnionitis. At term and preterm, pregnancies with maternal overweight and obesity had a high percentage increase in proportion of immature placentae compared to normal weight. Placental maturity did not associate with infant birth outcomes. We observed placental hypermaturity and altered placental morphometry among preterm pregnancies with chorioamnionitis, suggestive of altered placental development, which may inform about pregnancies susceptible to preterm birth and infection. Conclusions: Our data increase our understanding of how common metabolic exposures and preterm birth, in the absence of other comorbidities or complications, potentially contribute to poor pregnancy outcomes and developmental programming.

Optimizing perinatal wellbeing in pregnancy with obesity: a clinical trial with a multi-component nutrition intervention for prevention of gestational diabetes and infant growth and neurodevelopment impairment

Pregnancy complicated by obesity represents an increased risk of unfavorable perinatal outcomes such as gestational diabetes mellitus (GDM), hypertensive disorders in pregnancy, preterm birth, and impaired fetal growth, among others. Obesity is associated with deficiencies of micronutrients, and pregnant women with obesity may have higher needs. The intrauterine environment in pregnancies complicated with obesity is characterized by inflammation and oxidative stress, where maternal nutrition and metabolic status have significant influence and are critical in maternal health and in fetal programming of health in the offspring later in life. Comprehensive lifestyle interventions, including intensive nutrition care, are associated with a lower risk of adverse perinatal outcomes. Routine supplementation during pregnancy includes folic acid and iron; other nutrient supplementation is recommended for high-risk women or women in low-middle income countries. This study is an open label randomized clinical trial of parallel groups (UMIN Clinical Trials Registry: UMIN000052753, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000060194) to evaluate the effect of an intensive nutrition therapy and nutrient supplementation intervention (folic acid, iron, vitamin D, omega 3 fatty acids, myo-inositol and micronutrients) in pregnant women with obesity on the prevention of GDM, other perinatal outcomes, maternal and newborn nutritional status, and infant growth, adiposity, and neurodevelopment compared to usual care. Given the absence of established nutritional guidelines for managing obesity during pregnancy, there is a pressing need to develop and implement new nutritional programs to enhance perinatal outcomes.

Enhancing endometrial receptivity: the roles of human chorionic gonadotropin in autophagy and apoptosis regulation in endometrial stromal cells

Inadequate endometrial receptivity often results in embryo implantation failure and miscarriage. Human chorionic gonadotropin (hCG) is a key signaling molecule secreted during early embryonic development, which regulates embryonic maternal interface signaling and promotes embryo implantation. This study aimed to examine the impact of hCG on endometrial receptivity and its underlying mechanisms. An exploratory study was designed, and endometrial samples were obtained from women diagnosed with simple tubal infertility or male factor infertile (n = 12) and recurrent implantation failure (RIF, n = 10). Using reverse transcription-quantitative PCR and western blotting, luteinizing hormone (LH)/hCG receptor (LHCGR) levels and autophagy were detected in the endometrial tissues. Subsequently, primary endometrial stromal cells (ESCs) were isolated from these control groups and treated with hCG to examine the presence of LHCGR and markers of endometrial receptivity (HOXA10, ITGB3, FOXO1, LIF, and L-selectin ligand) and autophagy-related factors (Beclin1, LC3, and P62). The findings revealed that the expressions of receptivity factors, LHCGR, and LC3 were reduced in the endometrial tissues of women with RIF compared with the control group, whereas the expression of P62 was elevated. The administration of hCG to ESCs specifically activated LHCGR, stimulating an increase in the endometrial production of HOXA10, ITGB3, FOXO1, LIF and L-selectin ligands. Furthermore, when ESCs were exposed to 0.1 IU/mL hCG for 72 h, the autophagy factors Beclin1 and LC3 increased within the cells and P62 decreased. Moreover, the apoptotic factor Bax increased and Bcl-2 declined. However, when small interfering RNA was used to knock down LHCGR, hCG was less capable of controlling endometrial receptivity and autophagy molecules in ESCs. In addition, hCG stimulation enhanced the phosphorylation of ERK1/2 and mTOR proteins. These results suggest that women with RIF exhibit lower levels of LHCGR and compromised autophagy function in their endometrial tissues. Thus, hCG/LHCGR could potentially improve endometrial receptivity by modulating autophagy and apoptosis.

The effect of fetal hypoxia on myeloperoxidase levels in cord blood: a prospective study

BACKGROUND

We aimed to compare myeloperoxidase (MPO) levels in cord blood samples of mothers with and without perinatal hypoxia, since fetal hypoxia results in decreased pH, base excess, and an increase in pCO2 and lactate levels.

METHODS

We enrolled 42 pregnant women to this cross-sectional analytic study if they had met following criteria: uneventful gestational follow-ups, no known chronic or pregnancy-associated diseases, a BMI of <29.9, a singleton pregnancy, those with pregnancy over 34 weeks. The exclusion criteria for the study and control groups were as follows: presence of multiple pregnancies, fetal abnormality, any disease diagnosed before or during antenatal follow-up e.g., diabetes, hypertension, thyroid dysfunction, uncontrolled endocrine disease or abnormal kidney function, autoimmune disease, chronic inflammatory diseases, IUGR, preeclampsia), maternal age below 18 or above 35, intrauterine exitus, pregnancy with assisted reproductive technique, alcohol or smoking addiction, and any chronic drug use. The subjects were 1:1 randomized to either hypoxic newborns (N.=21) and those in the control group (N.=21) and their myeloperoxidase levels were measured from cord blood samples. Results were expressed as U/L. Patient data regarding age, gestation, parity, birth weight, birth length, APGAR scores, and neonatal complications were collected. All the women signed written informed consent forms and accepted verbal consent before being included in the study.

RESULTS

The mean age of the study population was 26.9±5.3 years. The mean BMI was 28.3±3.5 kg/m2. For the hypoxic group, 21 newborns with cord blood below 7.25 were included in the study group. The bloods with pH above 7.25 formed the control group. Mean pH and five (5) minute APGAR scores were found to be significantly lower in the study group, while base excess (BE) was found to be significantly higher. In this study, we compared the MPO levels of hypoxic newborns and those in the control group, and we did not find a significant difference between the two groups (P=0.147). Pearson Correlation Analysis is at -0.566 with P value (0.008) showing significant negative correlation between MPO and pH in the study group.

CONCLUSIONS

We found that MPO values are negatively correlated with cord blood pH among newborns diagnosed with fetal hypoxia.

Placenta-Specific Transcripts Containing Androgen Response Elements Are Altered In Silico by Male Growth Outcomes

A birthweight centile (BWC) below the 25th is associated with an elevated risk of adverse perinatal outcomes, particularly among males. This male vulnerability may stem from alterations in placenta-specific androgen signalling, a signalling axis that involves the androgen receptor (AR)-mediated regulation of target genes containing androgen response elements (AREs). In this study, we examined global and ARE-specific transcriptomic signatures in term male placentae (≥37 weeks of gestation) across BWC subcategories (<10th, 10th-30th, >30th) using RNA-seq and gene set enrichment analysis. ARE-containing transcripts in placentae with BWCs below the 10th percentile were upregulated compared to those in the 10th-30th and >30th percentiles, which coincided with the enrichment of gene sets related to hypoxia and the suppression of gene sets associated with mitochondrial function. In the absence of ARE-containing transcripts in silico, <10th and 10th-30th BWC subcategory placentae upregulated gene sets involved in vasculature development, immune function, and cell adhesion when compared to those in the >30th BWC subcategory. Collectively, our in silico findings suggest that changes in the expression of ARE-containing transcripts in male placentae may contribute to impaired placental vasculature and therefore result in reduced fetal growth outcomes.

Host-gut microbiota interactions during pregnancy

Mammalian pregnancy is characterized by a well-known suite of physiological changes that support fetal growth and development, thereby positively affecting both maternal and offspring fitness. However, mothers also experience trade-offs between current and future maternal reproductive success, and maternal responses to these trade-offs can result in mother-offspring fitness conflicts. Knowledge of the mechanisms through which these trade-offs operate, as well as the contexts in which they operate, is critical for understanding the evolution of reproduction. Historically, hormonal changes during pregnancy have been thought to play a pivotal role in these conflicts since they directly and indirectly influence maternal metabolism, immunity, fetal growth and other aspects of offspring development. However, recent research suggests that gut microbiota may also play an important role. Here, we create a foundation for exploring this role by constructing a mechanistic model linking changes in maternal hormones, immunity and metabolism during pregnancy to changes in the gut microbiota. We posit that marked changes in hormones alter maternal gut microbiome composition and function both directly and indirectly via impacts on the immune system. The gut microbiota then feeds back to influence maternal immunity and metabolism. We posit that these dynamics are likely to be involved in mediating maternal and offspring fitness as well as trade-offs in different aspects of maternal and offspring health and fitness during pregnancy. We also predict that the interactions we describe are likely to vary across populations in response to maternal environments. Moving forward, empirical studies that combine microbial functional data and maternal physiological data with health and fitness outcomes for both mothers and infants will allow us to test the evolutionary and fitness implications of the gestational microbiota, enriching our understanding of the ecology and evolution of reproductive physiology.

Maternal Exercise Prior to and during Gestation Induces Sex-Specific Alterations in the Mouse Placenta

While exercise (EX) during pregnancy is beneficial for both mother and child, little is known about the mechanisms by which maternal exercise mediates changes in utero. Six-week-old female C57BL/6 mice were divided into two groups: with (exercise, EX; N = 7) or without (sedentary, SED; N = 8) access to voluntary running wheels. EX was provided via 24 h access to wheels for 10 weeks prior to conception until late pregnancy (18.5 days post coitum). Sex-stratified placentas and fetal livers were collected. Microarray analysis of SED and EX placentas revealed that EX affected gene transcript expression of 283 and 661 transcripts in male and female placentas, respectively (±1.4-fold, p < 0.05). Gene Set Enrichment and Ingenuity Pathway Analyses of male placentas showed that EX led to inhibition of signaling pathways, biological functions, and down-regulation of transcripts related to lipid and steroid metabolism, while EX in female placentas led to activation of pathways, biological functions, and gene expression related to muscle growth, brain, vascular development, and growth factors. Overall, our results suggest that the effects of maternal EX on the placenta and presumably on the offspring are sexually dimorphic.

Comparison of maternal and neonatal survival exposed to humidifier disinfectants during perinatal periods: a case-series study

A humidifier disinfectant (HD) has been prohibited by the government due to its serious effects on the human body. Several studies on the relationship between HD and lung diseases have been performed independently on children and adults. However, there have been no reports on the effects of HD exposure on pregnant women and their foetuses. Therefore, the present study was conducted to investigate the effects of HD exposure on the foetuses of women who encountered HD during pregnancy. A total of 56 cases were recruited from 2017 to 2019 through the Korea Environmental Industry & Technology Institute, and data obtained from the medical records included maternal date of birth, maternal date of death, maternal start and end date of HD exposure, maternal date of symptom onset, neonatal birthday, neonatal birthweight, gestational age, and neonatal survival status within 28 days. All data were retrospectively investigated through medical records. Of the 47 mothers, 20 (42.6%) mothers survived, and 27 (57.4%) mothers died. In the group of survivors, there was a shorter period of total HD use, period of HD use before pregnancy and period of HD use to onset of symptoms. Shorter durations of HD use resulted in higher survival rate of mothers. HD use caused an increase in gestational age surviving foetuses, and foetal mortality increased when clinical symptoms developed before birth.

Whole Genome Assembly and Annotation of Blackstripe Livebearer Poeciliopsis prolifica

The blackstripe livebearer Poeciliopsis prolifica is a live-bearing fish belonging to the family Poeciliidae with high level of postfertilization maternal investment (matrotrophy). This viviparous matrotrophic species has evolved a structure similarly to the mammalian placenta. Placentas have independently evolved multiple times in Poeciliidae from nonplacental ancestors, which provide an opportunity to study the placental evolution. However, there is a lack of high-quality reference genomes for the placental species in Poeciliidae. In this study, we present a 674 Mb assembly of P. prolifica in 504 contigs with excellent continuity (contig N50 7.7 Mb) and completeness (97.2% Benchmarking Universal Single-Copy Orthologs [BUSCO] completeness score, including 92.6% single-copy and 4.6% duplicated BUSCO score). A total of 27,227 protein-coding genes were annotated from the merged datasets based on bioinformatic prediction, RNA sequencing and homology evidence. Phylogenomic analyses revealed that P. prolifica diverged from the guppy (Poecilia reticulata) ∼19 Ma. Our research provides the necessary resources and the genomic toolkit for investigating the genetic underpinning of placentation.

Influence of Maternal Diet and Environmental Factors on Fetal Development

This Special Issue of Nutrients, "Influence of Maternal Diet and Environmental Factors on Fetal Development", requests articles on the roles of maternal diet and environmental factors such as microbiota, plastics, and endocrine disruptive chemicals impact fetal development [...].

Expression of nutrient transporters in placentas affected by gestational diabetes: role of leptin

Gestational diabetes mellitus (GDM) is the most frequent pathophysiological state of pregnancy, which in many cases produces fetuses with macrosomia, requiring increased nutrient transport in the placenta. Recent studies by our group have demonstrated that leptin is a key hormone in placental physiology, and its expression is increased in placentas affected by GDM. However, the effect of leptin on placental nutrient transport, such as transport of glucose, amino acids, and lipids, is not fully understood. Thus, we aimed to review literature on the leptin effect involved in placental nutrient transport as well as activated leptin signaling pathways involved in the expression of placental transporters, which may contribute to an increase in placental nutrient transport in human pregnancies complicated by GDM. Leptin appears to be a relevant key hormone that regulates placental transport, and this regulation is altered in pathophysiological conditions such as gestational diabetes. Adaptations in the placental capacity to transport glucose, amino acids, and lipids may underlie both under- or overgrowth of the fetus when maternal nutrient and hormone levels are altered due to changes in maternal nutrition or metabolic disease. Implementing new strategies to modulate placental transport may improve maternal health and prove effective in normalizing fetal growth in cases of intrauterine growth restriction and fetal overgrowth. However, further studies are needed to confirm this hypothesis.

Altered expression of nutrient transporters in syncytiotrophoblast membranes in preeclampsia placentae

INTRODUCTION

Expression of nutrient transporters in the placenta affects fetal growth. This study reports the protein expression of nutrient transporters in the syncytial membranes [microvillous membrane (MVM) and basal membrane (BM)] of normotensive control and preeclampsia placentae.

METHODS

Placentae were collected from fourteen normotensive control women and fourteen women with preeclampsia. The syncytiotrophoblast MVM and BM membranes were isolated. The protein expression of glucose transporter (GLUT1), vitamin B₁₂ transporter (CD320) and fatty acid transporters (FATP2, FATP4) was assessed in both the membranes.

RESULTS

Comparison between membranes demonstrates similar CD320 protein expression in normotensive group whereas, in preeclampsia placentae it was higher in the BM as compared to MVM (p < 0.05). FATP2&4 protein expression was higher in the BM as compared to their respective MVM fraction in both the groups (p < 0.01 for both). Comparison between groups demonstrates higher GLUT1 expression in the MVM (p < 0.05) and BM (p < 0.05) whereas lower CD320 expression in the MVM (p < 0.05) of preeclampsia placentae as compared to their respective membranes in normotensive control. Furthermore, GLUT1 protein expression was positively associated and CD320 protein expression was negatively associated with maternal body mass index (BMI) (p < 0.05 for both). No difference was observed in the FATP2&4 protein expression. However, FATP4 protein expression was negatively associated with maternal blood pressure (p < 0.05 for MVM; p = 0.060 for BM) and birth weight (p < 0.05 for both membranes).

DISCUSSION

The current study for the first time demonstrates differential expression of various transporters in the syncytiotrophoblast membranes of the preeclampsia placentae which may influence fetal growth.

Maternal and Child Health, Non-Communicable Diseases and Metabolites

Mothers influence the health and disease trajectories of their children, particularly during the critical developmental windows of fetal and neonatal life reflecting the gestational-fetal and lactational-neonatal phases. As children grow and develop, they are exposed to various stimuli and insults, such as metabolites, that shape their physiology and metabolism to impact their health. Non-communicable diseases, such as diabetes, cardiovascular disease, cancer and mental illness, have high global prevalence and are increasing in incidence. Non-communicable diseases often overlap with maternal and child health. The maternal milieu shapes progeny outcomes, and some diseases, such as gestational diabetes and preeclampsia, have gestational origins. Metabolite aberrations occur from diets and physiological changes. Differential metabolite profiles can predict the onset of non-communicable diseases and therefore inform prevention and/or better treatment. In mothers and children, understanding the metabolite influence on health and disease can provide insights for maintaining maternal physiology and sustaining optimal progeny health over the life course. The role and interplay of metabolites on physiological systems and signaling pathways in shaping health and disease present opportunities for biomarker discovery and identifying novel therapeutic agents, particularly in the context of maternal and child health, and non-communicable diseases.

Blood Biomarkers in the Fetally Growth Restricted and Small for Gestational Age Neonate: Associations with Brain Injury

Fetal growth restriction (FGR) and small for gestational age (SGA) infants have increased risk of mortality and morbidity. Although both FGR and SGA infants have low birthweights for gestational age, a diagnosis of FGR also requires assessments of umbilical artery Doppler, physiological determinants, neonatal features of malnutrition, and in utero growth retardation. Both FGR and SGA are associated with adverse neurodevelopmental outcomes ranging from learning and behavioral difficulties to cerebral palsy. Up to 50% of FGR, newborns are not diagnosed until around the time of birth, yet this diagnosis lacks further indication of the risk of brain injury or adverse neurodevelopmental outcomes. Blood biomarkers may be a promising tool. Defining blood biomarkers indicating an infant's risk of brain injury would provide the opportunity for early detection and therefore earlier support. The aim of this review was to summarize the current literature to assist in guiding the future direction for the early detection of adverse brain outcomes in FGR and SGA neonates. The studies investigated potential diagnostic blood biomarkers from cord and neonatal blood or serum from FGR and SGA human neonates. Results were often conflicting with heterogeneity common in the biomarkers examined, timepoints, gestational age, and definitions of FGR and SGA used. Due to these variations, it was difficult to draw strong conclusions from the results. The search for blood biomarkers of brain injury in FGR and SGA neonates should continue as early detection and intervention is critical to improve outcomes for these neonates.

Causal effects of maternal exposure to PM2.5 during pregnancy on depression symptoms in adolescence: Identifying vulnerable windows and subpopulations in a national cohort study

Few studies have examined the causal relationship between chronic exposure to air pollutants during pregnancy and depression in adolescent offspring. In addition, it has not been investigated whether exposure is most harmful to adolescents in certain populations and at certain stages of pregnancy. A total of 1975 adolescents from 1632 families from the China Family Panel Study, a representative national longitudinal cohort, were included in this study. We used high-resolution satellite retrieval data to assess the PM_2.5 exposure of mothers during pregnancy. Specifically, we employed a two-stage instrumental variable model (IV-2SLS) within the counterfactual causal inference framework, and selected and validated appropriate instruments, thereby mitigating potentially biased results arising from bi-direction between dependent and independent variables. This approach allowed us to explore the causal relationship between maternal PM_2.5 exposure during pregnancy and adolescent depression symptoms. The endogeneity of air pollution during pregnancy and the need for a causal model were suggested by the results of the model comparisons. Using the IV-2SLS model, we found that maternal exposure to PM_2.5 during pregnancy exacerbates depressive symptoms in the offspring during adolescence (β = 0.2, 95% CI: 0.05-0.34). We also found that exposure during the first trimester may cause greater harm. Adolescents with low household income, being male, irregular exercise habits, living in rural areas, and having mothers with poorer mental status may be more vulnerable. The findings suggest that maternal exposure to PM_2.5 during pregnancy may have a negative impact on the depression symptoms of offspring in adolescence and that more attention should be paid to vulnerable populations and the window of vulnerability.

Intrinsic sexual dimorphism in the placenta determines the differential response to benzene exposure

Maternal immune activation (MIA) by environmental challenges is linked to severe developmental complications, such as neurocognitive disorders, autism, and even fetal/maternal death. Benzene is a major toxic compound in air pollution that affects the mother as well as the fetus and has been associated with reproductive complications. Our objective was to elucidate whether benzene exposure during gestation triggers MIA and its impact on fetal development. We report that benzene exposure during pregnancy leads MIA associated with increased fetal resorptions, fetal growth, and abnormal placenta development. Furthermore, we demonstrate the existence of a sexual dimorphic response to benzene exposure in male and female placentas. The sexual dimorphic response is a consequence of inherent differences between male and female placenta. These data provide crucial information on the origins or sexual dimorphism and how exposure to environmental factors can have a differential impact on the development of male and female offspring.

PFASs: What can we learn from the European Human Biomonitoring Initiative HBM4EU

Per- and polyfluoroalkyl substances (PFASs) were one of the priority substance groups selected which have been investigated under the ambitious European Joint programme HBM4EU (2017-2022). In order to answer policy relevant questions concerning exposure and health effects of PFASs in Europe several activities were developed under HBM4EU namely i) synthesis of HBM data generated in Europe prior to HBM4EU by developing new platforms, ii) development of a Quality Assurance/Quality Control Program covering 12 biomarkers of PFASs, iii) aligned and harmonized human biomonitoring studies of PFASs. In addition, some cohort studies (on mother-child exposure, occupational exposure to hexavalent chromium) were initiated, and literature researches on risk assessment of mixtures of PFAS, health effects and effect biomarkers were performed. The HBM4EU Aligned Studies have generated internal exposure reference levels for 12 PFASs in 1957 European teenagers aged 12-18 years. The results showed that serum levels of 14.3% of the teenagers exceeded 6.9 μg/L PFASs, which corresponds to the EFSA guideline value for a tolerable weekly intake (TWI) of 4.4 ng/kg for some of the investigated PFASs (PFOA, PFOS, PFNA and PFHxS). In Northern and Western Europe, 24% of teenagers exceeded this level. The most relevant sources of exposure identified were drinking water and some foods (fish, eggs, offal and locally produced foods). HBM4EU occupational studies also revealed very high levels of PFASs exposure in workers (P95: 192 μg/L in chrome plating facilities), highlighting the importance of monitoring PFASs exposure in specific workplaces. In addition, environmental contaminated hotspots causing high exposure to the population were identified. In conclusion, the frequent and high PFASs exposure evidenced by HBM4EU strongly suggests the need to take all possible measures to prevent further contamination of the European population, in addition to adopting remediation measures in hotspot areas, to protect human health and the environment. HBM4EU findings also support the restriction of the whole group of PFASs. Further, research and definition for additional toxicological dose-effect relationship values for more PFASs compounds is needed.

Prenatal Exposure to Air Pollutants and Attentional Deficit Hyperactivity Disorder Development in Children: A Systematic Review

Up to 9.5% of the world's population is diagnosed with attention deficit/hyperactivity disorder (ADHD), making it one of the most common childhood disorders. Air pollutants could be considered an environmental risk condition for ADHD, but few studies have specifically investigated the effect of prenatal exposure. The current paper reviews the studies conducted on the association between prenatal air pollutants (PM, NO_x, SO₂, O₃, CO and PAH) and ADHD development in children. From the 890 studies searched through PubMed, Google Scholar, Scopus, and Web of Science, 15 cohort studies met the inclusion criteria. NOS and WHO guidelines were used for quality and risk of bias assessment. The accumulative sample was 589,400 of children aged 3-15 years. Most studies reported an association between ADHD symptoms and prenatal PAH and PM exposure. Data available on NO₂ and SO₂ were inconsistent, whereas the effect of CO/O₃ is barely investigated. We observed heterogeneity through an odd ratio forest plot, and discrepancies in methodologies across the studies. Eight of the fifteen studies were judged to be of moderate risk of bias in the outcome measurement. In a nutshell, future studies should aim to minimize heterogeneity and reduce bias by ensuring a more representative sample, standardizing exposure and outcome assessments.

Maternal and Intrauterine Influences on Feto-Placental Growth Are Accompanied by Sexually Dimorphic Changes in Placental Mitochondrial Respiration, and Metabolic Signalling Pathways

Adverse maternal environments such as small size, malnutrition, and metabolic conditions are known to influence fetal growth outcomes. Similarly, fetal growth and metabolic alterations may alter the intrauterine environment and affect all fetuses in multiple gestation/litter-bearing species. The placenta is the site of convergence between signals derived from the mother and the developing fetus/es. Its functions are fuelled by energy generated by mitochondrial oxidative phosphorylation (OXPHOS). The aim of this study was to delineate the role of an altered maternal and/or fetal/intrauterine environment in feto-placental growth and placental mitochondrial energetic capacity. To address this, in mice, we used disruptions of the gene encoding phosphoinositol 3-kinase (PI3K) p110α, a growth and metabolic regulator to perturb the maternal and/or fetal/intrauterine environment and study the impact on wildtype conceptuses. We found that feto-placental growth was modified by a perturbed maternal and intrauterine environment, and effects were most evident for wildtype males compared to females. However, placental mitochondrial complex I+II OXPHOS and total electron transport system (ETS) capacity were similarly reduced for both fetal sexes, yet reserve capacity was additionally decreased in males in response to the maternal and intrauterine perturbations. These were also sex-dependent differences in the placental abundance of mitochondrial-related proteins (e.g., citrate synthase and ETS complexes), and activity of growth/metabolic signalling pathways (AKT and MAPK) with maternal and intrauterine alterations. Our findings thus identify that the mother and the intrauterine environment provided by littermates modulate feto-placental growth, placental bioenergetics, and metabolic signalling in a manner dependent on fetal sex. This may have relevance for understanding the pathways leading to reduced fetal growth, particularly in the context of suboptimal maternal environments and multiple gestation/litter-bearing species.

A screening test proposal for congenital defects based on maternal serum metabolomics profile

BACKGROUND

Historically, noninvasive techniques are only able to identify chromosomal anomalies that accounted for <50% of all congenital defects; the other congenital defects are diagnosed via ultrasound evaluations in the later stages of pregnancy. Metabolomic analysis may provide an important improvement, potentially addressing the need for novel noninvasive and multicomprehensive early prenatal screening tools. A growing body of evidence outlines notable metabolic alterations in different biofluids derived from pregnant women carrying fetuses with malformations, suggesting that such an approach may allow the discovery of biomarkers common to most fetal malformations. In addition, metabolomic investigations are inexpensive, fast, and risk-free and often generate high performance screening tests that may allow early detection of a given pathology.

OBJECTIVE

This study aimed to evaluate the diagnostic accuracy of an ensemble machine learning model based on maternal serum metabolomic signatures for detecting fetal malformations, including both chromosomal anomalies and structural defects.

STUDY DESIGN

This was a multicenter observational retrospective study that included 2 different arms. In the first arm, a total of 654 Italian pregnant women (334 cases with fetuses with malformations and 320 controls with normal developing fetuses) were enrolled and used to train an ensemble machine learning classification model based on serum metabolomics profiles. In the second arm, serum samples obtained from 1935 participants of the New Zealand Screening for Pregnancy Endpoints study were blindly analyzed and used as a validation cohort. Untargeted metabolomics analysis was performed via gas chromatography-mass spectrometry. Of note, 9 individual machine learning classification models were built and optimized via cross-validation (partial least squares-discriminant analysis, linear discriminant analysis, naïve Bayes, decision tree, random forest, k-nearest neighbor, artificial neural network, support vector machine, and logistic regression). An ensemble of the models was developed according to a voting scheme statistically weighted by the cross-validation accuracy and classification confidence of the individual models. This ensemble machine learning system was used to screen the validation cohort.

RESULTS

Significant metabolic differences were detected in women carrying fetuses with malformations, who exhibited lower amounts of palmitic, myristic, and stearic acids; N-α-acetyllysine; glucose; L-acetylcarnitine; fructose; para-cresol; and xylose and higher levels of serine, alanine, urea, progesterone, and valine (P<.05), compared with controls. When applied to the validation cohort, the screening test showed a 99.4%±0.6% accuracy (specificity of 99.9%±0.1% [1892 of 1894 controls correctly identified] with a sensitivity of 78%±6% [32 of 41 fetal malformations correctly identified]).

CONCLUSION

This study provided clinical validation of a metabolomics-based prenatal screening test to detect the presence of congenital defects. Further investigations are needed to enable the identification of the type of malformation and to confirm these findings on even larger study populations.

Placental Metabolomics of Fetal Growth Restriction

Fetal growth restriction is an obstetrical pathological condition that causes high neonatal mortality and morbidity. The mechanisms of its onset are not completely understood. Metabolites were extracted from 493 placentas from non-complicated pregnancies in Hamilton Country, TN (USA), and analyzed by gas chromatography-mass spectrometry (GC-MS). Newborns were classified according to raw fetal weight (low birth weight (LBW; <2500 g) and non-low birth weight (Non-LBW; >2500 g)), and according to the calculated birth weight centile as it relates to gestational age (small for gestational age (SGA), large for gestational age (LGA), and adequate for gestational age (AGA)). Mothers of LBW infants had a lower pre-pregnancy weight (66.2 ± 17.9 kg vs. 73.4 ± 21.3 kg, p < 0.0001), a lower body mass index (BMI) (25.27 ± 6.58 vs. 27.73 ± 7.83, p < 0.001), and a shorter gestation age (246.4 ± 24.0 days vs. 267.2 ± 19.4 days p < 0.001) compared with non-LBW. Marital status, tobacco use, and fetus sex affected birth weight centile classification according to gestational age. Multivariate statistical comparisons of the extracted metabolomes revealed that asparagine, aspartic acid, deoxyribose, erythritol, glycerophosphocholine, tyrosine, isoleucine, serine, and lactic acid were higher in both SGA and LBW placentas, while taurine, ethanolamine, β-hydroxybutyrate, and glycine were lower in both SGA and LBW. Several metabolic pathways are implicated in fetal growth restriction, including those related to the hypoxia response and amino-acid uptake and metabolism. Inflammatory pathways are also involved, suggesting that fetal growth restriction might share some mechanisms with preeclampsia.

Early Life Stress (ELS) Effects on Fetal and Adult Bone Development

Early life stress (ELS) refers to harmful environmental events (i.e., poor maternal health, metabolic restraint, childhood trauma) occurring during the prenatal and/or postnatal period, which may cause the 'epigenetic corruption' of cellular and molecular signaling of mental and physical development. While the impact of ELS in a wide range of human diseases has been confirmed, the ELS susceptibility to bone diseases has been poorly explored. In this review, to understand the potential mediating pathways of ELS in bone diseases, PRISMA criteria were used to analyze different stress protocols in mammal models and the effects elicited in dams and their progeny. Data collected, despite the methodological heterogeneity, show that ELS interferes with fetal bone formation, also revealing that the stress type and affected developmental phase may influence the variety and severity of bone anomalies. Interestingly, these findings highlight the maternal and fetal ability to buffer stress, establishing a new role for the placenta in minimizing ELS perturbations. The functional link between ELS and bone impairments will boost future investigations on maternal stress transmission to the fetus and, parallelly, help the assessment of catch-up mechanisms of skeleton adaptations from the cascading ELS effects.

Maternal plasma transforming growth factor-β1 (TGF-β1) and newborn size: the Araraquara Cohort Study

OBJECTIVE

To investigate associations of maternal and cord blood cytokine patterns with newborn size and body composition.

METHODS

This cross-sectional study involved 70 pregnant women and their healthy newborns selected from the "Araraquara Cohort Study". Newborn anthropometric measurements were recorded at birth. Body composition was evaluated by air displacement plethysmography. Maternal blood samples were collected from pregnant women between 30 and 36 weeks of gestation, and umbilical cord blood samples were collected immediately after placenta discharge. The concentrations of the cytokines were determined in plasma by ELISA. Multiple linear regression models were used to assess associations between maternal and cord blood cytokine concentrations and newborn anthropometry and body composition measurements.

RESULTS

Maternal plasma TGF-β1 concentration was inversely associated with newborn weight (β = -43.0; p = 0.012), length (β = -0.16, p = 0.028), head circumference (β = -0.13, p = 0.004), ponderal index (β = -0.32, p = 0.011) and fat-free mass (β = -0.05, p = 0.005). However, the association persisted just for head circumference (β = -0.26; p = 0.030) and ponderal index (β = - 0.28; p = 0.028), after adjusting for pre-gestational BMI, gestational weight gain, gestational age, hours after delivery, newborn sex, smoking and alcohol consumption.

CONCLUSIONS

Maternal plasma TGF-β1 concentration may be involved in the regulation of newborn size, mainly head circumference and ponderal index. Further cohort studies are necessary to investigate the role of TGF-β1 in different trimesters of pregnancy and its effect during the early stages of fetal development.

Ferumoxytol dynamic contrast enhanced magnetic resonance imaging identifies altered placental cotyledon perfusion in rhesus macaques†

Identification of placental dysfunction in early pregnancy with noninvasive imaging could be a valuable tool for assessing maternal and fetal risk. Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) can be a powerful tool for interrogating placenta health. After inoculation with Zika virus or sham inoculation at gestation age (GA) 45 or 55 days, animals were imaged up to three times at GA65, GA100, and GA145. DCE MRI images were acquired at all imaging sessions using ferumoxytol, an iron nanoparticle-based contrast agent, and analyzed for placental intervillous blood flow, number of perfusion domains, and perfusion domain volume. Cesarean section was performed at GA155, and the placenta was photographed and dissected for histopathology. Photographs were used to align cotyledons with estimated perfusion domains from MRI, allowing comparison of estimated cotyledon volume to pathology. Monkeys were separated into high and low pathology groups based on the average number of pathologies present in the placenta. Perfusion domain flow, volume, and number increased through gestation, and total blood flow increased with gestation for both low pathology and high pathology groups. A statistically significant decrease in perfusion domain volume associated with pathology was detected at all gestational ages. Individual perfusion domain flow comparisons demonstrated a statistically significant decrease with pathology at GA100 and GA145, but not GA65. Since ferumoxytol is currently used to treat anemia during human pregnancy and as an off-label MRI contrast agent, future transition of this work to human pregnancy may be possible.

Aberrant inflammation in rat pregnancy leads to cardiometabolic alterations in the offspring and intrauterine growth restriction in the F2 generation

Children of women with pre-eclampsia have increased risk of cardiovascular (CV) and metabolic disease in adult life. Furthermore, the risk of pregnancy complications is higher in daughters born to women affected by pre-eclampsia than in daughters born after uncomplicated pregnancies. While aberrant inflammation contributes to the pathophysiology of pregnancy complications, including pre-eclampsia, the contribution of maternal inflammation to subsequent risk of CV and metabolic disease as well as pregnancy complications in the offspring remains unclear. Here, we demonstrate that 24-week-old female rats (F1) born to dams (F0) exposed to lipopolysaccharide (LPS) during pregnancy (to induce inflammation) exhibited mild systolic dysfunction, increased cardiac growth-related gene expression, altered glucose tolerance, and coagulopathy; whereas male F1 offspring exhibited altered glucose tolerance and increased visceral fat accumulation compared with F1 sex-matched offspring born to saline-treated dams. Both male and female F1 offspring born to LPS-treated dams had evidence of anemia. Fetuses (F2) from F1 females born to LPS-treated dams were growth restricted, and this reduction in fetal growth was associated with increased CD68 positivity (indicative of macrophage presence) and decreased expression of glucose transporter-1 in their utero-placental units. These results indicate that abnormal maternal inflammation can contribute to increased risk of CV and metabolic disease in the offspring, and that the effects of inflammation may cross generations. Our findings provide evidence in support of early screening for CV and metabolic disease, as well as pregnancy complications in offspring affected by pre-eclampsia or other pregnancy complications associated with aberrant inflammation.

Cardiovascular Dysfunction in Intrauterine Growth Restriction

PURPOSE OF REVIEW

We highlight important new findings on cardiovascular dysfunction in intrauterine growth restriction.

RECENT FINDINGS

Intrauterine growth restriction (IUGR) is a multifactorial condition which negatively impacts neonatal growth during pregnancy and is associated with health problems during the lifespan. It affects 5-15% of all pregnancies in the USA and Europe with varying percentages in developing countries. Epidemiological studies have reported that IUGR is associated with the pathogenesis of hypertension, activation of the renin-angiotensin system (RAS), disruption in placental-mTORC and TGFβ signaling cascades, and endothelial dysfunction in IUGR fetuses, children, adolescents, and adults resulting in the development of cardiovascular diseases (CVD). Experimental studies are needed to investigate therapeutic measures to treat increased blood pressure (BP) and long-term CVD problems in people affected by IUGR. We outline the mechanisms mediating fetal programming of hypertension in developing CVD. We have reviewed findings from different experimental models focusing on recent studies that demonstrate CVD in IUGR.

Maternal Underweight and Obesity Are Associated with Placental Pathologies in Human Pregnancy

Maternal underweight and obesity are prevalent conditions, associated with chronic, low-grade inflammation, poor fetal development, and long-term adverse outcomes for the child. The placenta senses and adapts to the pregnancy environment in an effort to support optimal fetal development. However, the mechanisms driving these adaptations, and the resulting placental phenotypes, are poorly understood. We hypothesised that maternal underweight and obesity would be associated with increased prevalence of placental pathologies in term and preterm pregnancies. Data from 12,154 pregnancies were obtained from the Collaborative Perinatal Project, a prospective cohort study conducted from 1959 to 1974. Macro- and microscopic placental pathologies were analysed across maternal prepregnancy body mass index (BMI) to assess differences in the presence of pathologies among underweight, overweight, and obese BMI groups compared to normal weight reference BMI at term and preterm. Placental pathologies were also assessed across fetal sex. Pregnancies complicated by maternal obesity had placentae with increased fetal inflammation at preterm, and increased inflammation of maternal gestational tissues at term. In term pregnancies, increasing maternal BMI associated with increased maternal vascular malperfusion (MVM), odds of an appropriately mature placenta for gestational age, and placental weight, and decreased placental efficiency. Male placentae, independent of maternal BMI, had increased inflammation, MVM, and placental efficiency than female placentae, particularly at term. Maternal underweight and obesity are not inert conditions for the placenta, and the histomorphological changes driven by suboptimal maternal BMI may serve as indicators of adversities experienced in utero and potential predictors of future health trajectories.

Placental epigenetic gestational aging in relation to maternal sociodemographic factors and smoking among infants born extremely preterm: a descriptive study

Social determinants of health (SDoH) are defined as the conditions in which people are born, grow, live, work, and age. The distribution of these conditions is influenced by underlying structural factors and may be linked to adverse pregnancy outcomes through epigenetic modifications of gestational tissues. A promising modification is epigenetic gestational age (eGA), which captures 'biological' age at birth. Measuring eGA in placenta, an organ critical for foetal development, may provide information about how SDoH 'get under the skin' during pregnancy to influence birth outcomes and ethnic/racial disparities. We examined relationships of placental eGA with sociodemographic factors, smoking, and two key clinical outcomes: Apgar scores and NICU length of stay. Using the Robust Placental Clock, we estimated eGA for placental samples from the Extremely Low Gestational Age Newborns cohort (N = 408). Regression modelling revealed smoking during pregnancy was associated with placental eGA acceleration (i.e., eGA higher than chronologic gestational age). This association differed by maternal race: among infants born to mothers racialized as Black, we observed greater eGA acceleration (+0.89 week, 95% CI: 0.38, 1.40) as compared to those racialized as white (+0.27 week, 95% CI: -0.06, 0.59). Placental eGA acceleration was also correlated with shorter NICU lengths of stay, but only among infants born to mothers racialized as Black (-0.08 d/week-eGA, 95% CI: -0.12, -0.05). Together, these observed associations suggest that interpretations of epigenetic gestational aging may be tissue-specific.

Gestational Exposure to Cyfluthrin through Endoplasmic Reticulum (ER) Stress-Mediated PERK Signaling Pathway Impairs Placental Development

Cyfluthrin, a typical type II pyrethroid pesticide, is widely used in house hygiene and agricultural pest control. Several epidemiological investigations have found that maternal pyrethroid exposure is connected to adverse pregnancy outcomes. However, the underlying mechanisms remain to be elucidated. Thus, we evaluated the effect of cyfluthrin exposure during pregnancy on placenta development in vivo. In the current study, Pregnant SD rats were randomly divided into four groups and administered 6.25, 12.5, and 25 mg/kg body weight cyfluthrin or an equivalent volume of corn oil by gavage from GD0 to GD19. The results have shown that gestational exposure to cyfluthrin exerted no effect on the fetal birth defect, survival to PND4, or fetal resorption and death. However, live fetuses and implantation sites significantly decreased in the high-dose cyfluthrin-treated group. Moreover, a significant reduction in placenta weight and diameter was observed in rats. Correspondingly, the fetal weight and crown-rump length from dams exposed to cyfluthrin were reduced. Cyfluthrin-treat groups, the total area of the placenta, spongiotrophoblast area, and labyrinth area had abnormal changes. Meanwhile, the area of blood sinusoid and CD34-positive blood vessel numbers in the placenta were considerably reduced, as well as abnormal expression of placental pro-angiogenic and anti-angiogenic factors in dams exposed to cyfluthrin. Further observation by transmission electron microscopy revealed significant changes in the ultrastructure of the medium-dose and high-dose groups. Additional experiments showed gestational exposure to cyfluthrin inhibited proliferation and induced apoptosis of placentas, as decreased PCNA-positive cells and increased TUNEL-positive cells. Furthermore, western blot and qPCR analysis revealed that gestational exposure to medium-dose and high-dose cyfluthrin increased the expression of GRP78, and three downstream mRNA and proteins (p-eIF2α, ATF4, and CHOP) of the PERK signaling, indicating that endoplasmic reticulum (ER) stress-mediated PERK/eIF2α/ATF4/CHOP signaling pathway in rat placentas was activated. Our study demonstrated that gestational exposure to cyfluthrin leads to placental developmental disorder, which might be associated with ER stress-mediated PERK signaling pathway.

Using non-parametric Bayes shrinkage to assess relationships between multiple environmental and social stressors and neonatal size and body composition in the Healthy Start cohort

BACKGROUND

Both environmental and social factors have been linked to birth weight and adiposity at birth, but few studies consider the effects of exposure mixtures. Our objective was to identify which components of a mixture of neighborhood-level environmental and social exposures were driving associations with birth weight and adiposity at birth in the Healthy Start cohort.

METHODS

Exposures were assessed at the census tract level and included air pollution, built environment characteristics, and socioeconomic status. Prenatal exposures were assigned based on address at enrollment. Birth weight was measured at delivery and adiposity was measured using air displacement plethysmography within three days. We used non-parametric Bayes shrinkage (NPB) to identify exposures that were associated with our outcomes of interest. NPB models were compared to single-predictor linear regression. We also included generalized additive models (GAM) to assess nonlinear relationships. All regression models were adjusted for individual-level covariates, including maternal age, pre-pregnancy BMI, and smoking.

RESULTS

Results from NPB models showed most exposures were negatively associated with birth weight, though credible intervals were wide and generally contained zero. However, the NPB model identified an interaction between ozone and temperature on birth weight, and the GAM suggested potential non-linear relationships. For associations between ozone or temperature with birth weight, we observed effect modification by maternal race/ethnicity, where effects were stronger for mothers who identified as a race or ethnicity other than non-Hispanic White. No associations with adiposity at birth were observed.

CONCLUSIONS

NPB identified prenatal exposures to ozone and temperature as predictors of birth weight, and mothers who identify as a race or ethnicity other than non-Hispanic White might be disproportionately impacted. However, NPB models may have limited applicability when non-linear effects are present. Future work should consider a two-stage approach where NPB is used to reduce dimensionality and alternative approaches examine non-linear effects.

Glucose and oxygen in the early intrauterine environment and their role in developmental abnormalities

The early life environment can have profound impacts on the developing conceptus in terms of both growth and morphogenesis. These impacts can manifest in a variety of ways, including congenital fetal anomalies, placental dysfunction with subsequent effects on fetal growth, and adverse perinatal outcomes, or via effects on long-term health outcomes that may not be detected until later childhood or adulthood. Two key examples of environmental influences on early development are explored: maternal hyperglycaemia and gestational hypoxia. These are increasingly common pregnancy exposures worldwide, with potentially profound impacts on population health. We explore what is known regarding the mechanisms by which these environmental exposures can impact early intrauterine development and thus result in adverse outcomes in the immediate, short, and long term.

Maternal diabetes and childhood cancer risks in offspring: two population-based studies

BACKGROUND

The effect of maternal diabetes on childhood cancer has not been widely studied.

METHODS

We examined this in two population-based studies in Denmark (N = 6420 cancer cases, 160,484 controls) and Taiwan (N = 2160 cancer cases, 2,076,877 non-cases) using logistic regression and Cox proportional hazard regression adjusted for birth year, child's sex, maternal age and birth order.

RESULTS

Gestational diabetes in Denmark [odds ratio (OR) = 0.98, 95% confidence interval (CI): 0.71-1.35] or type II and gestational diabetes in Taiwan (type II: hazard ratio (HR) = 0.81, 95% CI: 0.63-1.05; gestational diabetes: HR = 1.06, 95% CI: 0.92-1.22) were not associated with cancer (all types combined). In Denmark, maternal type I diabetes was associated with the risk of glioma (OR = 2.33, 95% CI: 1.04-5.22), while in Taiwan, the risks of glioma (HR = 1.59, 95% CI: 1.01-2.50) were elevated among children whose mothers had gestational diabetes. There was a twofold increased risk for hepatoblastoma with maternal type II diabetes (HR = 2.02, 95% CI: 1.02-4.00).

CONCLUSIONS

Our results suggest that maternal diabetes is an important risk factor for certain types of childhood cancers, emphasising the need for effective interventions targeting maternal diabetes to prevent serious health effects in offspring.

Progesterone Induces Apoptosis and Steroidogenesis in Porcine Placental Trophoblasts

Placentation and placental steroidogenesis are important for pregnancy and maternal−fetal health. As pregnancy progresses, the main site of progesterone (P4) synthesis changes from the corpus luteum to the placenta, in which placental trophoblasts are the main cell type for P4 synthesis. Therefore, this study investigated the effects of P4 on apoptosis and steroidogenesis in porcine placental trophoblasts and the underlying molecular mechanisms. Porcine placental trophoblasts were treated with different concentrations of P4 for 48 h in a serum-free medium in vitro. Cell number, steroidogenesis, and relevant gene and protein expression levels were detected. A high dose of P4 (10.0 μM) significantly increased P4 (p < 0.01), androstenedione (p < 0.05), testosterone (p < 0.05), and estradiol (p < 0.05) production in porcine placental trophoblasts compared with that in control cells, while a low dose of P4 (1 × 10−3 μΜ) had no marked impact on steroid production. The mRNA expression of apoptosis-related genes (CASP3, CASP8, and Bax) (p < 0.05) and steroidogenesis-related genes (CYP11A1, CYP19A1, and StAR) (p < 0.01) was upregulated, and the expression of HSD3B and HSD17B4 was inhibited (p < 0.05) in the porcine placental trophoblasts treated with high doses of P4. Low doses of P4 had a lighter effect on gene expression than high doses. The expression of apoptosis-related proteins CASP3 (p < 0.05), and Bax (p < 0.01) and steroidogenesis-related proteins CYP19A1 (p < 0.05) and StAR (p < 0.01) was raised, but the proliferation-related protein CCND2 (p < 0.01) was downregulated in the pTr cells treated with high dose of P4. In comparison, a low dose of P4 inhibited the expression of Bax, CYP11A1 (all p < 0.01), and CCND2 (p < 0.05), but the expression of CASP3 (p < 0.05) and StAR (p < 0.01) was upregulated. In summary, excessive P4 can induce the apoptosis of porcine placental trophoblasts and lead to abnormal steroidogenesis in the placenta and hormone imbalance.

A Proteomic Study of the Effect of N-acetylcysteine on the Regulation of Early Pregnancy in Goats

Simple Summary

Early pregnancy regulation is an extremely complex process that is influenced by various factors. We previously mined the differentially expressed genes affected by N-acetyl-L-cysteine (NAC) in early pregnancy in goats via transcriptome sequencing. We found that NAC increased the number of lambs by affecting the immune pathway in ewes and enhancing antioxidation. Based on this, we here explored the effect of NAC on early pregnancy in goats at the protein level. The results showed a difference in the expression of uterine keratin and increases in the levels of antioxidant indices and hormones in doe serum.

Abstract

Dietary supplementation with N-acetyl-L-cysteine (NAC) may support early pregnancy regulation and fertility in female animals. The purpose of this study was to investigate the effect of supplementation with 0.07% NAC on the expression of the uterine keratin gene and protein in Qianbei-pockmarked goats during early pregnancy using tandem mass spectrometry (TMT) relative quantitative proteomics. The results showed that there were significant differences in uterine keratin expression between the experimental group (NAC group) and the control group on day 35 of gestation. A total of 6271 proteins were identified, 6258 of which were quantified by mass spectrometry. There were 125 differentially expressed proteins (DEPs), including 47 upregulated and 78 downregulated proteins, in the NAC group. Bioinformatic analysis showed that these DEPs were mainly involved in the transport and biosynthesis of organic matter and were related to the binding of transition metal ions, DNA and proteins and the catalytic activity of enzymes. They were enriched in the Jak-STAT signalling pathway, RNA monitoring pathway, amino acid biosynthesis, steroid biosynthesis and other pathways that may affect the early pregnancy status of does through different pathways and thus influence early embryonic development. Immunohistochemistry, real-time quantitative PCR and Western blotting were used to verify the expression and localization of glial fibrillary acidic protein (GFAP) and pelota mRNA surveillance and ribosomal rescue factor (PELO) in uterine horn tissue. The results showed that both PELO and GFAP were localized to endometrial and stromal cells, consistent with the mass spectrometry data at the transcriptional and translational levels. Moreover, NAC supplementation increased the levels of the reproductive hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), oestradiol (E2), progesterone (P4), superoxide dismutase (SOD), glutamate peroxidase (GSH-Px) and nitric oxide (NO) in the serum of does. These findings provide new insight into the mechanism by which NAC regulates early pregnancy and embryonic development in goats.