Time Course of Maternal Plasma Volume and Hormonal Changes in Women With Preeclampsia or Fetal Growth Restriction

The role of prenatal maternal sex steroid hormones in weight and adiposity at birth and growth trajectories during infancy

OBJECTIVE

Intrauterine factors can impact fetal and child growth and may underlie the developmental origins of childhood obesity. Sex steroid hormone exposure during pregnancy is a plausible target because of the impact on placental vascularization, nutrient transportation, adipogenesis, and epigenetic modifications. In this study we assessed maternal sex steroid hormones in each trimester in relation to birthweight, neonatal adiposity, and infant growth trajectories, and evaluated sensitive windows of development.

METHODS

Participants from a prospective pregnancy cohort who delivered at term were included in the analysis (n = 252). Estrone, estradiol, and estriol, as well as total and free testosterone throughout gestation were assessed using high-performance liquid chromatography and tandem mass spectrometry. Path analyses were used to assess the direct associations of sex steroid hormones in each trimester with birth outcomes and infant growth trajectories (birth to 12 months) adjusting for covariates and considering moderation by sex.

RESULTS

The associations between prenatal sex steroid hormones and fetal/infant growth varied by sex and timing of hormone exposure. First-trimester estrone was associated with higher birthweight z-scores (β = 0.37, 95% CI: 0.02, 0.73) and truncal skinfold thickness (TST) at birth (β = 0.94, 95% CI: 0.34, 1.54) in female infants. Third-trimester total testosterone was associated with higher TST at birth (β = 0.47, 95% CI: 0.03, 0.86) in both sexes. First-trimester estrone and estradiol and first- and third-trimester testosterone were associated with lower probabilities of high stable weight trajectory compared to low stable weight trajectory (Estrone: β = -3.87, 95% CI: -6.59, -1.16; Estradiol: β = -4.36, 95% CI: -7.62, -1.11; First-trimester testosterone: β = -3.53, 95% CI: -6.63, -0.43; Third-trimester testosterone: β = -3.67, 95% CI: -6.66, -0.69) during infancy in male infants.

CONCLUSIONS

We observed associations between prenatal sex steroid hormone exposure and birthweight, neonatal adiposity and infant growth that were sex and gestational timing dependent. Our findings suggest further investigation on additional mechanisms linking prenatal sex steroid exposure and fetal/postnatal growth is needed.

Maternal hemodynamics assessment: Key to unlocking ignored functionalities of the female circulation

This chapter focuses on currently underappreciated aspects of the maternal circulation: blood pressure phenotypes, venous hemodynamics, intra-abdominal pressure, and body water homeostasis. Based on the hemodynamic balance between cardiac output and total peripheral resistance, flow-dominant and resistance-dominant phenotypes of normotension and hypertension exist, with different impacts on gestational outcome. Cardiac diastolic function and venous hemodynamics play a prominent role in gestational changes in cardiac output. An increase in intra-abdominal pressure during pregnancy interferes with body water volume homeostasis, similar to syndromes of multi-organ dysfunctions in non-pregnant individuals. Today, non-invasive maternal hemodynamics assessment allows for obtaining important information on these ignored circulatory functions in addition to conventional sphygmomanometric blood pressure measurement. This offers perspectives to improve current strategies for screening, diagnosis, and management of gestational hypertension disorders, a path, however, to be paved first by intensified multifaceted and multidisciplinary research.

Application of a quantitative uncertainty assessment to develop ranges of plausible toxicity values when using observational data in risk assessment: a case study examining associations between PFOA and PFOS exposures and vaccine response

Traditional approaches for quantitatively characterizing uncertainty in risk assessment require adaptation to accommodate increased reliance on observational (vs experimental) studies in developing toxicity values. Herein, a case study with perfluorooctanoic acid (PFOA) and PFOS and vaccine response explores approaches for qualitative and-where possible-quantitative assessments of uncertainty at each step in the toxicity value development process when using observational data, including review and appraisal of individual studies, candidate study selection, dose-response modeling, and application of uncertainty factors. Each of the 15 studies identified had uncertainties due to risk of bias in confounding, outcome, and exposure ascertainment, likely contributing to the observed inconsistencies within and across studies, and resulting in lack of candidacy for dose-response assessment. Nonetheless, 2 representative studies were selected to demonstrate possible methods to quantify uncertainty in the remaining steps. Data simulations indicated lack of a clear dose-response relationship; dose-response models fit to representative simulations indicated high uncertainty in both the magnitude and direction of effect with simulated benchmark dose and its lower limit values varying at least 66- and 86-fold for PFOA and PFOS. Uncertainty factor application added minimal uncertainty. Combined, a high level of uncertainty was observed, precluding the ability to confidently assess causal dose-response relationships with the observational data, alone. This case study highlights the need for quantitative uncertainty analysis when developing toxicity values with observational data and, importantly, emphasizes the need for application of additional techniques to directly assess causality and the specificity of dose-response when relying on studies of association in quantitative risk assessment.

Metabolic profiles of meconium in preeclamptic and normotensive pregnancies

INTRODUCTION

Preeclampsia (PE) is a common vascular pregnancy disorder affecting maternal and fetal metabolism with severe immediate and long-term consequences in mothers and infants. During pregnancy, metabolites in the maternal circulation pass through the placenta to the fetus. Meconium, a first stool of the neonate, offers a view to maternal and fetoplacental unit metabolism and could add to knowledge on the effects of PE on the fetus and newborn.

OBJECTIVES

To compare meconium metabolome of infants from PE and normotensive pregnancies.

METHODS

A cohort of preeclamptic parturients and normotensive controls were recruited in Tampere University Hospital during 2019-2022. Meconium was sampled and its metabolome analyzed using liquid chromatography- mass spectrometry in 48 subjects in each group.

RESULTS

Differences in abundances of 1263 compounds, of which 19 could be annotated, were detected between the two groups. Several acylcarnitines, androsterone sulfate, three bile acids, amino acid derivatives (phenylacetylglutamine, epsilon-(gamma-glutamyl)lysine and N-(phenylacetyl)glutamic acid), as well as caffeine and paraxanthine were lower in the PE group compared to the control group. Urea and progesterone were higher in the PE group.

CONCLUSION

PE is associated with alterations in the meconium metabolome of infants. The differing abundances of several metabolites show alterations in the interaction between the fetoplacental unit and mother in PE, but whether they are a cause or an effect of the disorder remains to be further investigated.

Quercetin alleviates endothelial dysfunction in preeclampsia by inhibiting ferroptosis and inflammation through EGFR binding

Preeclampsia (PE) is a pregnancy-specific complication and there remains no effective treatment. Given the limitations on medication use during pregnancy, exploring natural, safe, and effective drugs for PE is worthwhile. We investigate the causal relationship between ferroptosis, inflammation, and PE, and determine the protective effects of quercetin (QCT), a representative compound that is classified as a flavanol, against endothelial dysfunction. Then, the target of QCT is predicted and verified. The prophylactic addition of a low dose of QCT rescues endothelial dysfunction, aiding in endothelial repair. Furthermore, QCT alleviates PE-like maternal manifestations and endothelial dysfunction in the placenta of the selective reduced uteroplacental perfusion (sRUPP) rat model through binding to the epidermal growth factor receptor (EGFR). The potential applications of QCT are expanded, offering the possibility of further development as a safe and effective preventive molecule for PE.

Disturbance of Fetal Growth by Azithromycin Through Induction of ER Stress in the Placenta

Aim: Azithromycin (AZM) is widely used to treat mycoplasma infection in pregnancy. However, there is no adequate evaluation of its side effect on the placenta. In this study, using human placental syncytiotrophoblasts and a mouse model, we investigated whether AZM use in pregnancy might adversely affect placental function and pregnancy outcome. Results: Transcriptomic analysis of AZM-treated human placental syncytiotrophoblasts showed increased expression of endoplasmic reticulum (ER) stress-related genes and decreased expression of genes for hormone production and growth factor processing. Verification studies showed that AZM increased the abundance of ER stress mediators (phosphorylated eIF2α, activating transcription factor 4 [ATF4], and C/EBP Homologous Protein [CHOP]) and decreased the abundance of enzymes involved in progesterone and estradiol synthesis (STS, CYP11A1, and CYP19A1) and insulin-like growth factor binding protein (IGFBP) cleavage (PAPPA and ADAM12) in human placental syncytiotrophoblasts. Inhibition of ER stress blocked AZM-induced decreases in the expression of CYP19A1, CYP11A1, PAPPA, and ADAM12, suggesting that the inhibition of AZM on those genes' expression was secondary to AZM-induced ER stress. Further mechanism study showed that increased ATF4 in ER stress might repressively interact with C/EBPα to suppress the expression of those genes, including CEBPA itself. Mouse studies showed that AZM administration decreased fetal weights along with increased ER stress mediators and decreased levels of insulin-like growth factor, estrogen, and progesterone in the maternal blood, which could be alleviated by inhibition of ER stress. Innovation and Conclusion: These findings first support the fact that AZM, often used during pregnancy, may affect fetal growth by inhibiting crucial enzymes for estrogen and progesterone synthesis and disrupting crucial proteases for IGFBP cleavage via inducing ER stress in placental syncytiotrophoblasts. Antioxid. Redox Signal. 42, 16-35.

Sensing Platform Based on Gold Nanoclusters and Nanoporous Anodic Alumina for Preeclampsia Detection

Preeclampsia is a pregnancy-specific hypertensive syndrome recognized as the leading cause of maternal and fetal morbidity worldwide. Early diagnosis is crucial for mitigating its adverse effects, and recent investigations have identified endoglin as a potential biomarker for this purpose. Here, we present the development of a hybrid biosensor platform for the ultrasensitive detection of endoglin, aimed at enabling the early diagnosis of preeclampsia. This platform integrates the high surface area properties of nanoporous anodic alumina (NAA) with the unique optical characteristics of gold nanoclusters (AuNCs) to achieve enhanced detection capabilities. The NAA surface functionalized to promote attachment of AuNCs, which then was functionalized with specific antibodies to confer selectivity towards endoglin. Photoluminescence (PL) analysis of the biosensor demonstrated a linear detection range of 10-50 ng/mL, with a detection limit of 5.4 ng/mL and a sensitivity of 0.004 a.u./(ng/mL). This proof-of-concept study suggests that the NAA-AuNCs-based biosensing platform holds significant potential for the development of ultrasensitive, portable, and cost-effective diagnostic tools for preeclampsia, offering a promising avenue for advancing prenatal care.

A Prospective Analysis of Per- and Polyfluoroalkyl Substances from Early Pregnancy to Delivery in the Atlanta African American Maternal-Child Cohort

BACKGROUND

Longitudinal trends in per- and polyfluoroalkyl substances (PFAS) serum concentrations across pregnancy have not been thoroughly examined, despite evidence linking prenatal PFAS exposures with adverse birth outcomes.

OBJECTIVES

We sought to characterize longitudinal PFAS concentrations across pregnancy and to examine the maternal-fetal transfer ratio among participants in a study of risk and protective factors for adverse birth outcomes among African Americans.

METHODS

In the Atlanta African American Maternal-Child cohort (2014-2020), we quantified serum concentrations of four PFAS in 376 participants and an additional eight PFAS in a subset of 301 participants during early (8-14 weeks gestation) and late pregnancy (24-30 weeks gestation). Among these, PFAS concentrations were also measured among 199 newborns with available dried blood spot (DBS) samples. We characterized the patterns, variability, and associations in PFAS concentrations at different time points across pregnancy using intraclass correlation coefficients (ICCs), maternal-newborn pairs transfer ratios, linear mixed effect models, and multivariable linear regression, adjusting for socioeconomic and prenatal predictors.

RESULTS

Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected in > 95 % of maternal samples, with PFHxS and PFOS having the highest median concentrations. We observed high variability in PFAS concentrations across pregnancy time points (ICC = 0.03 - 0.59 ). All median PFAS concentrations increased from early to late pregnancy, except for PFOA and N-methyl perfluorooctane sulfonamido acetic acid (NMFOSAA), which decreased [paired t -test for all PFAS p < 0.05 except for PFOA and perfluorobutane sulfonic acid (PFBS)]. Prenatal serum PFAS were weakly to moderately correlated with newborn DBS PFAS (- 0.05 < rho < 0.49 ). The median maternal-fetal PFAS transfer ratio was lower for PFAS with longer carbon chains. After adjusting for socioeconomic and prenatal predictors, in linear mixed effect models, the adjusted mean PFAS concentrations significantly increased during pregnancy, except for PFOA. In multivariable linear regression, PFAS concentrations in early pregnancy significantly predicted the PFAS concentrations in late pregnancy and in newborns.

DISCUSSION

We found that the concentrations of most PFAS increased during pregnancy, and the magnitude of variability differed by individual PFAS. Future studies are needed to understand the influence of within-person PFAS variability during and after pregnancy on birth outcomes. https://doi.org/10.1289/EHP14334.

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.

Visfatin (NAMPT) expression in human placenta cells in normal and pathological conditions and its hormonal regulation in trophoblast JEG-3 cells

Visfatin is an adipokine involved in energy metabolism, insulin resistance, inflammation, and female reproduction. Due to limited data about its action in the human placenta, the aims of our studies included the analysis of visfatin expression and immunolocalization in trophoblast cell lines JEG-3 and BeWo as well as in human placentas from normal and pathological pregnancies. Moreover, we also checked the hormonal regulation of visfatin levels and the molecular mechanism of observed changes in JEG-3 cells. Cell culture and placental fragments collection along with statistical analysis were performed using standard laboratory procedures also described in our previous papers. We demonstrated an increased gene and protein expression of visfatin in JEG-3, BeWo cells, while variable expression in maternal and fetal parts of normal/ pathological pregnancy placentas. In addition, the immunolocalization of visfatin was observed in the cytoplasm of both cell lines, the capillary epithelium of the maternal part and syncytiotrophoblasts of the placental fetal part; in all tested pathologies, the signal was also detected in decidual cells. Furthermore, we demonstrated that hormones: progesterone, estradiol, human chorionic gonadotropin, and insulin increased the visfatin levels in JEG-3 cells with the involvement of specific signaling pathways. Taken together, differences in the expression and localization of visfatin between normal and pathological placentas suggested that visfatin may be a potential marker for the diagnosis of pregnancy disorders. In addition, we found that placental levels of visfatin can be regulated by hormones known to modulate the function of placental cells.

Alterations of Placental Sodium in Preeclampsia: Trophoblast Responses

BACKGROUND

Evidence suggests that increasing salt intake in pregnancy lowers blood pressure, protecting against preeclampsia. We hypothesized that sodium (Na+) evokes beneficial placental signals that are disrupted in preeclampsia.

METHODS

Blood and urine were collected from nonpregnant women of reproductive age (n=26) and pregnant women with (n=50) and without (n=55) preeclampsia, along with placental biopsies. Human trophoblast cell lines and primary human trophoblasts were cultured with varying Na+ concentrations.

RESULTS

Women with preeclampsia had reduced placental and urinary Na+ concentrations, yet increased urinary angiotensinogen and reduced active renin, aldosterone concentrations, and osmotic response signal TonEBP (tonicity-responsive enhancer binding protein) expression. In trophoblast cell cultures, TonEBP was consistently increased upon augmented Na+ exposure. Mechanistically, inhibiting Na+/K+-ATPase or adding mannitol evoked the TonEBP response, whereas inhibition of cytoskeletal signaling abolished it.

CONCLUSIONS

Enhanced Na+ availability induced osmotic gradient-dependent cytoskeletal signals in trophoblasts, resulting in proangiogenic responses. As placental salt availability is compromised in preeclampsia, adverse systemic responses are thus conceivable.

Association between serum hormone levels in early pregnancy and risk of hypertensive diseases of pregnancy in women undergoing assisted reproduction

PURPOSE

We examined the association between progesterone (P4), estradiol (E2), and human chorionic gonadotropin (hCG) levels in early pregnancy and the development of hypertensive diseases of pregnancy among women undergoing assisted reproduction.

METHODS

Retrospective study including patients who underwent frozen embryo transfer (FET), ovarian stimulation (OS), or unassisted conception (UC) and had a live singleton birth. The primary outcome was the development of hypertensive diseases of pregnancy (gestational hypertension, preeclampsia, HELLP, or eclampsia). Secondary outcomes were the development of fetal intrauterine growth restriction (IUGR), gestational diabetes mellitus, birth weight, and pre-term birth. Hormone levels and the development of the outcomes were correlated.

RESULTS

A total of 681 patients were included; 189 had FET, 193 had OS, and 299 had UC. Patients undergoing FET or OS were not more likely to develop hypertensive diseases of pregnancy compared with UC patients. While median levels of E2 and P4 were significantly different between P-FET and NC-FET patients (E2: 252 vs 317 pg/mL, P4: 64 vs 29 ng/mL, respectively; both p < 0.01), rates of hypertensive diseases of pregnancy did not significantly differ between those two groups. In the multivariate analyses, P4, E2, and hCG were not associated with the development of hypertensive diseases of pregnancy, but progesterone levels were significantly higher among those with IUGR. This remained consistent when the analysis was limited to FET patients.

CONCLUSION

P4, E2, and hCG levels did not correlate with the development of hypertensive diseases of pregnancy but elevated progesterone levels did correlate with the development of IUGR.

The physiological and biochemical basis of potency thresholds modeled using human estrogen receptor alpha: implications for identifying endocrine disruptors

The endocrine system functions by interactions between ligands and receptors. Ligands exhibit potency for binding to and interacting with receptors. Potency is the product of affinity and efficacy. Potency and physiological concentration determine the ability of a ligand to produce physiological effects. The kinetic behavior of ligand-receptor interactions conforms to the laws of mass action. The laws of mass action define the relationship between the affinity of a ligand and the fraction of cognate receptors that it occupies at any physiological concentration. We previously identified the minimum ligand potency required to produce clinically observable estrogenic agonist effects via the human estrogen receptor-alpha (ERα). By examining data on botanical estrogens and dietary supplements, we demonstrated that ERα ligands with potency lower than one one-thousandth that of the primary endogenous hormone 17β-estradiol (E2) do not produce clinically observable estrogenic effects. This allowed us to propose a Human-Relevant Potency Threshold (HRPT) for ERα ligands of 1 × 10-4 relative to E2. Here, we test the hypothesis that the HRPT for ERα arises from the receptor occupancy by the normal metabolic milieu of endogenous ERα ligands. The metabolic milieu comprises precursors to hormones, metabolites of hormones, and other normal products of metabolism. We have calculated fractional receptor occupancies for ERα ligands with potencies below and above the previously established HRPT when normal circulating levels of some endogenous ERα ligands and E2 were also present. Fractional receptor occupancy calculations showed that individual ERα ligands with potencies more than tenfold higher than the HRPT can compete for occupancy at ERα against individual components of the endogenous metabolic milieu and against mixtures of those components at concentrations found naturally in human blood. Ligands with potencies less than tenfold higher than the HRPT were unable to compete successfully for ERα. These results show that the HRPT for ERα agonism (10-4 relative to E2) proposed previously is quite conservative and should be considered strong evidence against the potential for disruption of the estrogenic pathway. For chemicals with potency 10-3 of E2, the potential for estrogenic endocrine disruption must be considered equivocal and subject to the presence of corroborative evidence. Most importantly, this work demonstrates that the endogenous metabolic milieu is responsible for the observed ERα agonist HRPT, that this HRPT applies also to ERα antagonists, and it provides a compelling mechanistic explanation for the HRPT that is grounded in basic principles of molecular kinetics using well characterized properties and concentrations of endogenous components of normal metabolism.

The role of prenatal maternal sex steroid hormones in weight and adiposity at birth and growth trajectories during infancy

Objective

Intrauterine factors can impact fetal and child growth and may underlie the developmental origins of childhood obesity. Sex steroid hormone exposure during pregnancy is a plausible target because of the impact on placental vascularization, nutrient transportation, bone growth, adipogenesis, and epigenetic modifications. In this study we assessed maternal sex steroid hormones in each trimester in relation to birthweight, neonatal adiposity, and infant growth trajectories, and evaluate sensitive windows of development.

Methods

Participants from a prospective pregnancy cohort who delivered at term were included in the analysis (n=252). Estrone, estradiol, and estriol, as well as total and free testosterone throughout gestation were assessed using high-performance liquid chromatography and tandem mass spectrometry. Path analyses were used to assess the direct associations of sex steroid hormones in each trimester with birth outcomes and infant growth trajectories (birth to 12 months) adjusting for covariates and considering moderation by sex.

Results

The associations between prenatal sex steroid hormones and fetal/infant growth varied by sex and hormone assessment timing. First trimester estrone were associated with higher birthweight z-scores (β=0.37, 95%CI: 0.02, 0.73) and truncal skinfold thickness (TST) at birth (β=0.94, 95%CI: 0.34, 1.54) in female infants. Third trimester total testosterone was associated with higher TST at birth (β=0.61, 95%CI: 0.02, 1.21) in male infants. First trimester estrone/estradiol and first and third trimesters testosterone were associated with lower probabilities of high stable weight trajectory compared to low stable weight trajectory (Estrone: β=-3.87, 95%CI: -6.59, -1.16; First trimester testosterone: β=-3.53, 95%CI: -6.63, -0.43; Third trimester testosterone: β=-3.67, 95%CI: -6.66, -0.69) during infancy in male infants.

Conclusions

We observed associations between prenatal sex steroid hormone exposure and birthweight, neonatal adiposity and infant growth that were sex and gestational timing dependent. Our findings suggest further investigation on additional mechanisms linking prenatal sex steroid exposure and fetal/postnatal growth is needed.

FGR-associated placental insufficiency and capillary angiogenesis involves disruptions in human placental miRNAs and mRNAs

Fetal growth restriction (FGR) is one of the most common pregnancy complications culminating in adverse fetal outcome, including preterm birth, neonatal mortality and stillbirth. Compromised placental development and function, especially disruption in angiogenesis and inadequate nutrient supply are contributing factors. Fetal sex also influences placental function. Knowledge of gene expression changes and epigenetic factors contributing to placental dysfunction in FGR pregnancies will help identify biomarkers and help target interventions. This study tested the hypothesis that FGR pregnancies are associated with disruptions in miRNA - an epigenetic factor and mRNAs involving key mediators of angiogenesis and microvessel development. Changes in expression of key genes/proteins involved in placental dysfunction by RT-PCR and immunohistochemistry and miRNA changes by RNA sequencing were undertaken with term placenta from 12 control and 20 FGR pregnancies. Findings showed changes in expression of genes involved in steroidogenesis, steroid action, IGF family members, inflammatory cytokines and angiogenic factors in FGR pregnancies. In addition, upregulation of MIR451A and downregulation of MIR543 in placentas from FGR group with female newborns and upregulation of MIR520G in placentas from FGR group with male newborns were also noted. MIR451A and MIR543 have been implicated in angiogenesis. Consistent with gene changes, CD34, the microvessel angiogenesis marker, also showed reduced staining only in female FGR group. These findings provide evidence that epigentically regulated gene expression changes in angiogenesis and capillary development influence placental impairment in FGR pregnancies. Our preliminary observations also support for these changes to be driven in a sex-specific manner.

Restoration of serum estradiol and reduced incidence of miscarriage in patients with low serum estradiol during pregnancy: a retrospective cohort study using a multifactorial protocol including DHEA

Background

Low serum estradiol in early pregnancy is associated with an elevated risk of miscarriage. We sought to determine whether efforts to restore low blood estradiol via estradiol or dehydroepiandrosterone (DHEA) supplementation would reduce the risk of miscarriage as part of a multifactorial symptom-based treatment protocol.

Methods

This retrospective cohort study included women with low serum estradiol levels in early pregnancy, defined as ≤50% of reference levels by gestational age. Estradiol or DHEA were administered orally, and the primary outcome measure was serum estradiol level, in reference to gestational age. The secondary outcome measures included miscarriage, birth weight, and gestational age at birth.

Results

We found no significant effect of estradiol supplementation on serum estradiol levels referenced to gestational age, while DHEA supplementation strongly increased estradiol levels. For pregnancies with low estradiol, the miscarriage rate in the non-supplemented group was 45.5%, while miscarriage rate in the estradiol and DHEA supplemented groups were 21.2% (p = 0.067) and 17.5% (p = 0.038), respectively. Birth weight, size, gestational age, and preterm deliveries were not significantly different. No sexual abnormalities were reported in children (n = 29) of DHEA-supplemented patients after 5-7 years follow-up.

Conclusions

In conclusion, DHEA supplementation restored serum estradiol levels, and when included in the treatment protocol, there was a statistically significant reduction in miscarriage.

Classification of longitudinal profiles using semi-parametric nonlinear mixed models with P-Splines and the SAEM algorithm

In this work, we propose an extension of a semiparametric nonlinear mixed-effects model for longitudinal data that incorporates more flexibility with penalized splines (P-splines) as smooth terms. The novelty of the proposed approach consists of the formulation of the model within the stochastic approximation version of the EM algorithm for maximum likelihood, the so-called SAEM algorithm. The proposed approach takes advantage of the formulation of a P-spline as a mixed-effects model and the use of the computational advantages of the existing software for the SAEM algorithm for the estimation of the random effects and the variance components. Additionally, we developed a supervised classification method for these non-linear mixed models using an adaptive importance sampling scheme. To illustrate our proposal, we consider two studies on pregnant women where two biomarkers are used as indicators of changes during pregnancy. In both studies, information about the women's pregnancy outcomes is known. Our proposal provides a unified framework for the classification of longitudinal profiles that may have important implications for the early detection and monitoring of pregnancy-related changes and contribute to improved maternal and fetal health outcomes. We show that the proposed models improve the analysis of this type of data compared to previous studies. These improvements are reflected both in the fit of the models and in the classification of the groups.

The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

Association of Elevated Serum Aldosterone Concentrations in Pregnancy with Hypertension

Emerging evidence indicates a previously unrecognized, clinically relevant spectrum of abnormal aldosterone secretion associated with hypertension severity. It is not known whether excess aldosterone secretion contributes to hypertension during pregnancy. We quantified aldosterone concentrations and angiotensin peptides in serum (using liquid chromatography with tandem mass spectrometry) in a cohort of 128 pregnant women recruited from a high-risk obstetrics clinic and followed prospectively for the development of gestational hypertension, pre-eclampsia, superimposed pre-eclampsia, chronic hypertension, or remaining normotensive. The cohort was grouped by quartile of aldosterone concentration in serum measured in the first trimester, and blood pressure, angiotensin peptides, and hypertension outcomes compared across the four quartiles. Blood pressures and body mass index were greatest in the top and bottom quartiles, with the top quartile having the highest blood pressure throughout pregnancy. Further stratification of the top quartile based on increasing (13 patients) or decreasing (19 patients) renin activity over gestation revealed that the latter group was characterized by the highest prevalence of chronic hypertension, use of anti-hypertensive agents, pre-term birth, and intrauterine growth restriction. Serum aldosterone concentrations greater than 704 pmol/L, the 75th percentile defined within the cohort, were evident across all categories of hypertension in pregnancy, including normotensive. These findings suggest that aldosterone excess may underlie the development of hypertension in pregnancy in a significant subpopulation of individuals.

The AccuFlow sensor: a novel digital health tool to assess intrapartum blood loss at cesarean delivery

OBJECTIVES

During obstetric hemorrhage, peripheral vasoconstriction maintains heart rate and blood pressure until compensatory mechanisms are overwhelmed and patients deteriorate rapidly. Real-time perfusion measurements could quantify vasoconstriction, improving early recognition of hemorrhage and facilitating early intervention to reduce morbidity and mortality. The AccuFlow device makes rapid, non-invasive, quantitative measurements of perfusion, but has not been studied for hemorrhage detection or used in surgical settings. This study evaluated feasibility, tolerability, and preliminary efficacy of the AccuFlow for assessment of blood loss at cesarean delivery (CD).

METHODS

In this pilot study, sensors were applied to the wrist, forearm, bicep, and chest wall of 25 patients undergoing scheduled CD. Postoperatively, sensors were removed and patients rated the AccuFlow and the standard anesthesia monitoring equipment on a validated comfort rating scale for wearable computers (CRS). Blood loss was estimated by the surgical team (EBL) and calculated from change in hematocrit, weight, and height (CBL). CRS scores were compared via Wilcoxon signed ranks tests. Coefficients of correlation between sensor readings and CBL, and between EBL and CBL, were compared using Fisher's R-to-z transformation.

RESULTS

There were no safety events; no participants requested device removal. CRS ratings of the AccuFlow and the standard monitoring equipment were similar (7.2 vs. 8.8, p=0.25). Change in wrist perfusion from delivery to dressing placement was more strongly correlated with CBL than was EBL (R=-0.48 vs. R=0.087, p=0.03).

CONCLUSIONS

The AccuFlow sensor is well-tolerated and shows promise in detecting intrapartum hemorrhage, though larger studies are needed.

Maternal Serum Concentrations of Per- and Polyfluoroalkyl Substances in Early Pregnancy and Small for Gestational Age in Southern Sweden

Small for gestational age (SGA) is considered an adverse birth outcome. Per- and polyfluoralkyl substances (PFAS) have become increasingly investigated as contributing environmental factors, thus far with inconclusive results. The current study aimed to investigate the hypothesized association between increased maternal PFAS levels in early pregnancy and an increased risk for SGA birth. This population-based study used data from a sample of children born in Scania, Southern Sweden, between 1995 and 2009. Two groups were compared: cases born with SGA (n = 298) and non-SGA controls (n = 580). The cases consisted of two subgroups: one included women whose children's growth in late pregnancy was in the lowest quartile, and another included women from the remaining growth quartiles. Corresponding maternal serum samples were collected from a biobank and analyzed for concentrations of four types of PFAS: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The results were combined with information from birth registers and analyzed using Mann-Whitney U-tests and logistic regression-unadjusted as well as adjusted for potential confounders. In conclusion, elevated maternal concentrations of PFAS were not associated with an increased risk of SGA birth. However, significant ORs were observed in a subgroup analysis restricted to women of Nordic origin (unadjusted OR 3.2 and adjusted OR 2.4) for PFHxS.

Activation of the Renin-Angiotensin-Aldosterone System Is Attenuated in Hypertensive Compared with Normotensive Pregnancy

Hypertension during pregnancy increases the risk of adverse maternal and fetal outcomes, but the mechanisms of pregnancy hypertension are not precisely understood. Elevated plasma renin activity and aldosterone concentrations play an important role in the normal physiologic adaptation to pregnancy. These effectors are reduced in patients with pregnancy hypertension, creating an opportunity to define the features of the renin-angiotensin-aldosterone system (RAAS) that are characteristic of this disorder. In the current study, we used a novel LC-MS/MS-based methodology to develop comprehensive profiles of RAAS peptides and effectors over gestation in a cohort of 74 pregnant women followed prospectively for the development of gestational hypertension and pre-eclampsia (HYP, 27 patients) versus those remaining normotensive (NT, 47 patients). In NT pregnancy, the plasma renin activity surrogate, (PRA-S, calculated from the sum of Angiotensin I + Angiotensin II) and aldosterone concentrations significantly increased from the first to the third trimester, accompanied by a modest increase in the concentrations of angiotensin peptide metabolites. In contrast, in HYP pregnancies, PRA-S and angiotensin peptides were largely unchanged over gestation, and third-trimester aldosterone concentrations were significantly lower compared with those in NT pregnancies. The results indicated that the predominant features of pregnancies that develop HYP are stalled or waning activation of the RAAS in the second half of pregnancy (accompanied by unchanging levels of angiotensin peptides) and the attenuated secretion of aldosterone.

Maternal-fetal toxicity of Strychnos pseudoquina extract treatment during pregnancy

ETHNOPHARMACOLOGICAL RELEVANCE

Plants and herbs have been used by women throughout history for therapeutic purposes. Strychnos pseudoquina, a plant used in the treatment of various diseases, can also function as an abortive herb. There is no scientific confirmation of its effects during pregnancy, and the activity of this plant needs to be substantiated or refuted with experimental evidence.

AIM OF THE STUDY

Evaluating the effect of the S. pseudoquina aqueous extract on maternal reproductive toxicity and fetal development.

MATERIALS AND METHODS

The aqueous extract of S. pseudoquina bark was evaluated in Wistar rats. Pregnant rats were distributed into four experimental groups (n = 12 rats/group): Control = treated with water (vehicle); Treated 75, Treated 150, and Treated 300 = treated with S. pseudoquina at dose 75, 150 and 300 mg/kg, respectively. The rats were treated by an intragastric route (gavage) from day 0 to day 21 of pregnancy. At the end of pregnancy, maternal reproductive outcomes, organs, biochemical and hematological profiles, fetuses, and placentas were analyzed. Maternal toxicity was evaluated through body weight gain, water, and food intake. With knowledge of the harmful dosage of the plant, other rats were used on gestational day 4 for the evaluation of morphological analyses before embryo implantation. P < 0.05 was considered as statistically significant.

RESULTS

The S. pseudoquina treatment showed elevated liver enzymatic activities. The Treated 300 group presented toxicity with reduced maternal body weight, water and food intake, and increased kidney relative weight compared to those of the Control group. At a high dosage, the plant presents an abortifacient activity, confirmed by embryo losses before and after implantation and degenerated blastocysts. In addition, the treatment contributed to an increased percentage of fetal visceral anomalies, decreased ossification sites, and intrauterine growth restriction (300 mg/kg dose).

CONCLUSION

In general, our study showed that an aqueous extract of S. pseudoquina bark caused significant abortifacient activity that testified to its traditional use. Furthermore, the S. pseudoquina extract caused maternal toxicity that contributed to impaired embryofetal development. Therefore, the use of this plant should be completely avoided during pregnancy to prevent unintended abortion and risks to maternal-fetal health.

Maternal low and high hemoglobin concentrations and associations with adverse maternal and infant health outcomes: an updated global systematic review and meta-analysis

BACKGROUND

Growing evidence suggests low and high maternal hemoglobin (Hb) concentrations may have adverse consequences for maternal and child health. There remain questions on specific Hb thresholds to define anemia and high Hb as well as how cutoffs may vary by anemia etiology and timing of assessment.

METHODS

We conducted an updated systematic review (using PubMed and Cochrane Review) on low (< 110 g/L) and high (≥ 130 g/L) maternal Hb concentrations and associations with a range of maternal and infant health outcomes. We examined associations by timing of Hb assessment (preconception; first, second, and third trimesters, as well as at any time point in pregnancy), varying cutoffs used for defining low and high hemoglobin concentrations and performed stratified analyses by iron-deficiency anemia. We conducted meta-analyses to obtain odds ratios (OR) and 95% confidence intervals.

RESULTS

The updated systematic review included 148 studies. Low maternal Hb at any time point in pregnancy was associated with: low birthweight, LBW (OR (95% CI) 1.28 (1.22-1.35)), very low birthweight, VLBW (2.15 (1.47-3.13)), preterm birth, PTB (1.35 (1.29-1.42)), small-for-gestational age, SGA (1.11 (1.02-1.19)), stillbirth 1.43 (1.24-1.65)), perinatal mortality (1.75 (1.28-2.39)), neonatal mortality (1.25 (1.16-1.34), postpartum hemorrhage (1.69 (1.45-1.97)), transfusion (3.68 (2.58-5.26)), pre-eclampsia (1.57 (1.23-2.01)), and prenatal depression (1.44 (1.24-1.68)). For maternal mortality, the OR was higher for Hb < 90 (4.83 (2.17-10.74)) than for Hb < 100 (2.87 (1.08-7.67)). High maternal Hb was associated with: VLBW (1.35 (1.16-1.57)), PTB (1.12 (1.00-1.25)), SGA (1.17 (1.09-1.25)), stillbirth (1.32 (1.09-1.60)), maternal mortality (2.01 (1.12-3.61)), gestational diabetes (1.71 (1.19-2.46)), and pre-eclampsia (1.34 (1.16-1.56)). Stronger associations were noted earlier in pregnancy for low Hb and adverse birth outcomes while the role of timing of high Hb was inconsistent. Lower Hb cutoffs were associated with greater odds of poor outcomes; for high Hb, data were too limited to identify patterns. Information on anemia etiology was limited; relationships did not vary by iron-deficiency anemia.

CONCLUSION

Both low and high maternal Hb concentrations during pregnancy are strong predictors of adverse maternal and infant health outcomes. Additional research is needed to establish healthy reference ranges and design effective interventions to optimize maternal Hb during pregnancy.

Maternal hemoglobin concentrations across pregnancy and child health and development from birth through 6-7 years

Background

The role of changes in maternal hemoglobin (Hb) across pregnancy on child health and development (CHD) remains unclear.

Objective

We examined the association between maternal Hb trajectories and CHD outcomes: (a) birth outcomes (birth weight, length, gestational age, preterm, and small for gestational age); (b) child Hb at 3, 6, 12, and 24 months; and (c) motor and mental development at 12 and 24 months and cognitive functioning at age 6-7 years.

Methods

We used data from a randomized controlled trial (PRECONCEPT) conducted in Vietnam (N = 1,175 women enrolled during preconception with offspring follow-up through 6-7 years). Maternal Hb trajectories were developed using latent class analysis with Hb data at preconception, early (≤20 weeks), mid (21-29 weeks), and late (≥30 weeks) pregnancy. Multivariable linear and logistic regression models were used to assess the association between maternal Hb trajectories on CHD outcomes, adjusting for confounding variables at the maternal, child and household levels.

Results

Four distinct maternal Hb trajectories were identified. Track 1 (low initial Hb-decline) was associated with lower child Hb at 3 months (β [95% CI] -0.52 [-0.87, -0.16]), 6 months (-0.36 [-0.68, -0.05]), 12 months (-0.46 [-0.79, -0.13]), and 24 months (-0.44 [-0.72, -0.15]) and motor development at 12 months (-3.58 [-6.76, -0.40]) compared to track 4 (high initial Hb-decline). After adjustment for multiple testing, relationships remained robust with the exception of associations with child Hb at 6 months and motor development at 12 months. Track 2 (low initial Hb-improve) was the only Hb trajectory to increase across pregnancy; however, it was insufficiently powered. Track 3 (mid Hb-decline) was associated with lower child Hb at 12 months (-0.27 [-0.44, -0.10]) and 24 months (-0.20 [-0.34, -0.05]) compared to track 4 (high initial Hb-decline). Maternal Hb trajectories were not associated with birth outcomes or child development at 24 months or 6-7 years.

Conclusion

Maternal Hb trajectories during pregnancy are associated with child Hb concentrations across the first 1,000 days, but not with birth outcomes or later cognitive functioning. More work is needed to better understand and interpret changes in Hb levels during pregnancy especially in resource poor settings.

Progesterone Enhances the Invasion of Trophoblast Cells by Activating PI3K/AKT Signaling Pathway to Prevent Preeclampsia

We aimed to explore whether the effect of progesterone on preeclampsia via the PI3K/AKT signaling pathway. First, we studied the role of progesterone in preeclampsia patients and HTR-8/Svneo cells by adding progesterone. Then PI3K inhibitor LY294002 was added. The effects of progesterone on preeclampsia were also studied in animals by constructing a preeclampsia rat model. CCK-8 and Transwell assay were applied to measure cell viability and invasion ability. ELISA was performed to measure progesterone, MMP-2, MMP-9, pro-inflammatory factors TNF-α, IL-1β, and anti-inflammatory factors IL-4, IL-10, and IL-13 levels. HE staining was used to detect the pathological changes in uterine spiral artery. Western blot was performed to detect Cyclin D1, PCNA, MMP-2, MMP-9, inflammatory factors TNF-α, IL-1β, IL-4, IL-10, IL-13, and PI3K/AKT signaling pathway related proteins AKT, p-AKT, PI3K, and p-PI3K expressions. Progesterone could reduce blood pressure and urine protein in pregnant women with preeclampsia. TNF-α and IL-1β levels were decreased, but IL-4, IL-10, IL-13, cyclin D1, and PCNA levels were increased in pregnant women with preeclampsia after using progesterone. After the use of progesterone, the symptoms of the PE model group were improved. Among them, the lumen of the placental uterine spiral artery was enlarged, and the fibrinoid necrosis of the uterine wall and acute atherosclerotic lesions were relieved. In addition, progesterone promoted HTR-8/Svneo cells proliferation and invasion. However, high expression of MMP-2, MMP-9, p-AKT, and p-PI3K in Normal and preeclampsia groups caused by progesterone was weakened after adding LY294002, indicating that progesterone could activate PI3K/AKT signaling pathway to regulate HTR-8/Svneo cells. Progesterone decreased urine protein and blood pressure of preeclampsia rats in a concentration-dependent manner. Moreover, progesterone activated the PI3K/AKT signaling pathway and inhibited the inflammatory response in preeclampsia rats.

Serum estradiol to testosterone ratio as a novel predictor of severe preeclampsia in the first trimester

Preeclampsia (PE) is the most common medical complication during pregnancy and the second leading cause of maternal death worldwide. However, a better predictive model of PE remains to be explored. A total of 15 severe preeclampsia (sPE) and 75 healthy control patients were included in this study. Patient data was obtained from September 2019 to September 2021. Nuchal translucency (NT) and crown-rump length (CRL) of the fetus were acquired by ultrasound. Maternal blood samples were collected at 11⁺⁰ to 13⁺⁶  weeks of gestation. Chemiluminescent immunoassays were used to detect serum testosterone (T) and estradiol (E2) levels. Time-resolved fluorescence analysis was used to examine the levels of serum pregnancy-associated plasma protein A (PAPPA) and β-human chorionic gonadotrophin (β-HCG) protein. The sPE group exhibited increased T levels, and decreased E2 levels and E2/T ratios from 11 to 14 weeks of gestation, compared with the control group. E2 and the E2/T ratio showed positive linear correlation with CRL in pregnant women. Body-mass-index (BMI), T, and E2 were determined to be the main factors that affected the occurrence of sPE at the 12-week gestation period time point. The receiver operating characteristic (ROC) curve revealed that the AUC of the E2/T ratio was .717. The imbalanced T and E2 levels in the patients had a specific intrinsic relevance with sPE, which suggests them as novel predictors of the sPE.

Prenatal Perfluorooctanoic Acid (PFOA) Exposure Is Associated With Lower Infant Birthweight Within the MADRES Pregnancy Cohort

Introduction

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are persistent synthetic chemicals found in household products that can cross the placenta during pregnancy. We investigated whether PFAS exposure during pregnancy was associated with infant birth outcomes in a predominantly urban Hispanic population.

Methods

Serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured in 342 prenatal biospecimens (mean gestational age: 21 ± 9 weeks) from participants in the ongoing Maternal And Developmental Risks from Environmental and Social Stressors (MADRES) cohort. PFAS compounds were modeled continuously or categorically, depending on the percentage of samples detected. The birth outcomes assessed were birthweight, gestational age at birth, and birthweight for gestational age (BW-for-GA) z-scores that accounted for parity or infant sex. Single pollutant and multipollutant linear regression models were performed to evaluate associations between PFAS exposures and birth outcomes, adjusting for sociodemographic, perinatal, and study design covariates.

Results

Maternal participants (n = 342) were on average 29 ± 6 years old at study entry and were predominantly Hispanic (76%). Infants were born at a mean of 39 ± 2 weeks of gestation and weighed on average 3,278 ± 522 g. PFOS and PFHxS were detected in 100% of the samples while PFNA, PFOA, and PFDA were detected in 70%, 65%, and 57% of the samples, respectively. PFAS levels were generally lower in this cohort than in comparable cohorts. Women with detected levels of PFOA during pregnancy had infants weighing on average 119.7 g less (95% CI -216.7, -22.7) than women with undetected levels of PFOA in adjusted single pollutant models. PFOA results were also statistically significant in BW-for-GA z-score models that were specific for sex or parity. In models that were mutually adjusted for five detected PFAS compounds, PFOA results remained comparable; however, the association was only significant in BW-for-GA z-scores that were specific for parity (β = -0.3; 95% CI -0.6, -0.01). We found no significant adjusted associations with the remaining PFAS concentrations and the birth outcomes assessed.

Conclusion

Prenatal exposure to PFOA was associated with lower birthweight in infants, suggesting that exposure to these chemicals during critical periods of development might have important implications for children's health.

Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction

This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.

Materno-fetal iron transfer and the emerging role of ferroptosis pathways

A successful pregnancy and the birth of a healthy baby depend to a great extent on the controlled supply of essential nutrients via the placenta. Iron is essential for mitochondrial energy supply and oxygen distribution via the blood. However, its high reactivity requires tightly regulated transport processes. Disturbances of maternal-fetal iron transfer during pregnancy can aggravate or lead to severe pathological consequences for the mother and the fetus with lifelong effects. Furthermore, high intracellular iron levels due to disturbed gestational iron homeostasis have recently been associated with the non-apoptotic cell death pathway called ferroptosis. Therefore, the investigation of transplacental iron transport mechanisms, their physiological regulation and potential risks are of high clinical importance. The present review summarizes the current knowledge on principles and regulatory mechanisms underlying materno-fetal iron transport and gives insight into common pregnancy conditions in which iron homeostasis is disturbed. Moreover, the significance of the newly emerging ferroptosis pathway and its impact on the regulation of placental iron homeostasis, oxidative stress and gestational diseases will be discussed.

Association Between Exposure to Per- and Polyfluoroalkyl Substances and Birth Outcomes: A Systematic Review and Meta-Analysis

Background

A large body of emerging evidence suggests that per- and polyfluoroalkyl substances (PFAS) affect birth outcomes in various pathways, but the evidence is inconsistent. Therefore, this study aimed to systematically review the epidemiological evidence on PFAS exposure and birth outcomes.

Methods

Three electronic databases were searched for epidemiological studies through February 13, 2021. We used random-effects meta-analysis for eight birth outcome indicators to calculate summary effect estimates for various exposure types. The risk of bias and the overall quality and level of evidence for each exposure-outcome pair were assessed.

Results

The initial search identified 58 potentially eligible studies, of which 46 were ultimately included. Many PFAS were found to have previously unrecognized statistically significant associations with birth outcomes. Specifically, birth weight (BW) was associated with PFAS, with effect sizes ranging from −181.209 g (95% confidence interval (CI) = −360.620 to −1.798) per 1 ng/ml increase in perfluoroheptanesulfonate (PFHpS) to −24.252 g (95% CI = −38.574 to −9.930) per 1 ln (ng/ml) increase in perfluorodecaoic acid (PFDA). Similar patterns were observed between other PFAS and birth outcomes: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) with birth length (BL) and ponderal index (PI), PFOS and perfluorododecanoic acid (PFDoDA) with head circumference (HC), PFHpS with gestational age (GA), and perfluorononanoic acid (PFNA) and PFHpS with preterm birth (PTB). Additionally, PFDA showed a statistically significant association with small for gestational age (SGA). The level of the combined evidence for each exposure-outcome pair was considered to be “moderate”.

Conclusion

This study showed that PFAS exposure was significantly associated with increased risks of various adverse birth outcomes and that different birth outcome indicators had different degrees of sensitivity to PFAS. Further studies are needed to confirm our results by expanding the sample size, clarifying the effects of different types or doses of PFAS and the time of blood collection on birth outcomes, and fully considering the possible confounders.

Sustained Elevated Circulating Activin A Impairs Global Longitudinal Strain in Pregnant Rats: A Potential Mechanism for Preeclampsia-Related Cardiac Dysfunction

Mediators of cardiac injury in preeclampsia are not well understood. Preeclamptic women have decreased cardiac global longitudinal strain (GLS), a sensitive measure of systolic function that indicates fibrosis and tissue injury. GLS is worse in preeclampsia compared to gestational hypertension, despite comparable blood pressure, suggesting that placental factors may be involved. We previously showed that Activin A, a pro-fibrotic factor produced in excess by the placenta in preeclampsia, predicts impaired GLS postpartum. Here, we hypothesized that chronic excess levels of Activin A during pregnancy induces cardiac dysfunction. Rats were assigned to sham or activin A infusion (1.25–6 µg/day) on a gestational day (GD) 14 (n = 6–10/group). All animals underwent blood pressure measurement and comprehensive echocardiography followed by euthanasia and the collection of tissue samples on GD 19. Increased circulating activin A (sham: 0.59 ± 0.05 ng/mL, 6 µg/day: 2.8 ± 0.41 ng/mL, p < 0.01) was associated with impaired GLS (Sham: −22.1 ± 0.8%, 6 µg/day: −14.7 ± 1.14%, p < 0.01). Activin A infusion (6 µg/day) increased beta-myosin heavy chain expression in heart tissue, indicating cardiac injury. In summary, our findings indicate that increasing levels of activin A during pregnancy induces cardiac dysfunction and supports the concept that activin A may serve as a possible mediator of PE-induced cardiac dysfunction.

Hemodynamic pathways of gestational hypertension and preeclampsia

Gestational hypertension and preeclampsia are the 2 main types of hypertensive disorders in pregnancy. Noninvasive maternal cardiovascular function assessment, which helps obtain information from all the components of circulation, has shown that venous hemodynamic dysfunction is a feature of preeclampsia but not of gestational hypertension. Venous congestion is a known cause of organ dysfunction, but its potential role in the pathophysiology of preeclampsia is currently poorly investigated. Body water volume expansion occurs in both gestational hypertension and preeclampsia, and this is associated with the common feature of new-onset hypertension after 20 weeks of gestation. Blood pressure, by definition, is the product of intravascular volume load and vascular resistance (Ohm's law). Fundamentally, hypertension may present as a spectrum of cardiovascular states varying between 2 extremes: one with a predominance of raised cardiac output and the other with a predominance of increased total peripheral resistance. In clinical practice, however, this bipolar nature of hypertension is rarely considered, despite the important implications for screening, prevention, management, and monitoring of disease. This review summarizes the evidence of type-specific hemodynamic profiles in the latent and clinical stages of hypertensive disorders in pregnancy. Gestational volume expansion superimposed on an early gestational closed circulatory circuit in a pressure- or volume-overloaded condition predisposes a patient to the gradual deterioration of overall circulatory function, finally presenting as gestational hypertension or preeclampsia-the latter when venous dysfunction is involved. The eventual phenotype of hypertensive disorder is already predictable from early gestation onward, on the condition of including information from all the major components of circulation into the maternal cardiovascular assessment: the heart, central and peripheral arteries, conductive and capacitance veins, and body water content. The relevance of this approach, outlined in this review, openly invites for more in-depth research into the fundamental hemodynamics of gestational hypertensive disorders, not only from the perspective of the physiologist or the scientist, but also in assistance of clinicians toward understanding and managing effectively these severe complications of pregnancy.

Adaptive Changes in single-nephron GFR, Tubular Morphology, and Transport in a Pregnant Rat Nephron: Modeling and Analysis

Normal pregnancy is characterized by massive increases in plasma volume and electrolyte retention. Given that the kidneys regulate homeostasis of electrolytes and volume, the organ undergoes major adaptations in morphology, hemodynamics, and transport to achieve the volume and electrolyte retention required in pregnancy. These adaptations are complex, sometimes counterintuitive, and not fully understood. In addition, the demands of the developing fetus and placenta change throughout the pregnancy. For example, during late pregnancy, K⁺ retention and thus enhanced renal K⁺ reabsorption is required despite many kaliuretic factors. The goal of this study is to unravel how known adaptive changes along the nephrons contribute to the ability of the kidney to meet volume and electrolyte requirements in mid- and late pregnancy. We developed computational models of solute and water transport in the superficial nephron of the kidney of a rat in mid- and late pregnancy. The mid-pregnant and late-pregnant rat superficial nephron models predict that morphological adaptations and increased activity of the sodium hydrogen exchanger 3 (NHE3) and epithelial sodium channel (ENaC) are essential for enhanced Na⁺ reabsorption observed during pregnancy. Model simulations showed that for sufficient K⁺ reabsorption, increased H ⁺-K ⁺-ATPase activity and decreased K⁺ secretion along the distal segments is required in both mid- and late-pregnancy. Furthermore, certain known sex differences in renal transporter pattern (e.g., the higher NHE3 protein abundance but lower activity in the proximal tubules of virgin female rats compared to male) may serve to better prepare the female for the increased transport demand in pregnancy.

Vascular Dysfunction in Preeclampsia

Preeclampsia is a life-threatening pregnancy-associated cardiovascular disorder characterized by hypertension and proteinuria at 20 weeks of gestation. Though its exact underlying cause is not precisely defined and likely heterogenous, a plethora of research indicates that in some women with preeclampsia, both maternal and placental vascular dysfunction plays a role in the pathogenesis and can persist into the postpartum period. Potential abnormalities include impaired placentation, incomplete spiral artery remodeling, and endothelial damage, which are further propagated by immune factors, mitochondrial stress, and an imbalance of pro- and antiangiogenic substances. While the field has progressed, current gaps in knowledge include detailed initial molecular mechanisms and effective treatment options. Newfound evidence indicates that vasopressin is an early mediator and biomarker of the disorder, and promising future therapeutic avenues include mitigating mitochondrial dysfunction, excess oxidative stress, and the resulting inflammatory state. In this review, we provide a detailed overview of vascular defects present during preeclampsia and connect well-established notions to newer discoveries at the molecular, cellular, and whole-organism levels.

The roles of free iron, heme, haemoglobin, and the scavenger proteins haemopexin and alpha-1-microglobulin in preeclampsia and fetal growth restriction

BACKGROUND

Preeclampsia (PE) is a complex pregnancy syndrome characterised by maternal hypertension and organ damage after 20 weeks of gestation and is associated with an increased risk of cardiovascular disease later in life. Extracellular haemoglobin (Hb) and its metabolites heme and iron are highly toxic molecules and several defence mechanisms have evolved to protect the tissue.

OBJECTIVES

We will discuss the roles of free iron, heme, Hb, and the scavenger proteins haemopexin and alpha-1-microglobulin in pregnancies complicated by PE and fetal growth restriction (FGR).

CONCLUSION

In PE, oxidative stress causes syncytiotrophoblast (STB) stress and increased shedding of placental STB-derived extracellular vesicles (STBEV). The level in maternal circulation correlates with the severity of hypertension and supports the involvement of STBEVs in causing maternal symptoms in PE. In PE and FGR, iron homeostasis is changed, and iron levels significantly correlate with the severity of the disease. The normal increase in plasma volume taking place during pregnancy is less for PE and FGR and therefore have a different impact on, for example, iron concentration, compared to normal pregnancy. Excess iron promotes ferroptosis is suggested to play a role in trophoblast stress and lipotoxicity. Non-erythroid α-globin regulates vasodilation through the endothelial nitric oxide synthase pathway, and hypoxia-induced α-globin expression in STBs in PE placentas is suggested to contribute to hypertension in PE. Underlying placental pathology in PE with and without FGR might be amplified by iron and heme overload causing oxidative stress and ferroptosis. As the placenta becomes stressed, the release of STBEVs increases and affects the maternal vasculature.

Fetal Cardiac Lipid Sensing Triggers an Early and Sex-related Metabolic Energy Switch in Intrauterine Growth Restriction

CONTEXT

Intrauterine growth restriction (IUGR) is an immediate outcome of an adverse womb environment, exposing newborns to developing cardiometabolic disorders later in life.

OBJECTIVE

This study investigates the cardiac metabolic consequences and underlying mechanism of energy expenditure in developing fetuses under conditions of IUGR.

METHODS

Using an animal model of IUGR characterized by uteroplacental vascular insufficiency, mitochondrial function, gene profiling, lipidomic analysis, and transcriptional assay were determined in fetal cardiac tissue and cardiomyocytes.

RESULTS

IUGR fetuses exhibited an upregulation of key genes associated with fatty acid breakdown and β-oxidation (Acadvl, Acadl, Acaa2), and mitochondrial carnitine shuttle (Cpt1a, Cpt2), instigating a metabolic gene reprogramming in the heart. Induction of Ech1, Acox1, Acox3, Acsl1, and Pex11a indicated a coordinated interplay with peroxisomal β-oxidation and biogenesis mainly observed in females, suggesting sexual dimorphism in peroxisomal activation. Concurring with the sex-related changes, mitochondrial respiration rates were stronger in IUGR female fetal cardiomyocytes, accounting for enhanced adenosine 5'-triphosphate production. Mitochondrial biogenesis was induced in fetal hearts with elevated expression of Ppargc1a transcript specifically in IUGR females. Lipidomic analysis identified the accumulation of arachidonic, eicosapentaenoic, and docosapentaenoic polyunsaturated long-chain fatty acids (LCFAs) in IUGR fetal hearts, which leads to nuclear receptor peroxisome proliferator-activated receptor α (PPARα) transcriptional activation in cardiomyocytes. Also, the enrichment of H3K27ac chromatin marks to PPARα-responsive metabolic genes in IUGR fetal hearts outlines an epigenetic control in the early metabolic energy switch.

CONCLUSION

This study describes a premature and sex-related remodeling of cardiac metabolism in response to an unfavorable intrauterine environment, with specific LCFAs that may serve as predictive effectors leading to IUGR.

Secretory products of the corpus luteum and preeclampsia

BACKGROUND

Despite significant advances in our understanding of the pathophysiology of preeclampsia (PE), there are still many unknowns and controversies in the field. Women undergoing frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium have been found to have an unexpected increased risk of PE compared to women who receive embryos in a natural FET cycle. The differences in risk have been hypothesized to be related to the absence or presence of a functioning corpus luteum (CL).

OBJECTIVE AND RATIONALE

To evaluate the literature on secretory products of the CL that could be essential for a healthy pregnancy and could reduce the risk of PE in the setting of FET.

SEARCH METHODS

For this review, pertinent studies were searched in PubMed/Medline (updated June 2020) using common keywords applied in the field of assisted reproductive technologies, CL physiology and preeclampsia. We also screened the complete list of references in recent publications in English (both animal and human studies) on the topics investigated. Given the design of this work as a narrative review, no formal criteria for study selection or appraisal were utilized.

OUTCOMES

The CL is a major source of multiple factors regulating reproduction. Progesterone, estradiol, relaxin and vasoactive and angiogenic substances produced by the CL have important roles in regulating its functional lifespan and are also secreted into the circulation to act remotely during early stages of pregnancy. Beyond the known actions of progesterone and estradiol on the uterus in early pregnancy, their metabolites have angiogenic properties that may optimize implantation and placentation. Serum levels of relaxin are almost undetectable in pregnant women without a CL, which precludes some maternal cardiovascular and renal adaptations to early pregnancy. We suggest that an imbalance in steroid hormones and their metabolites and polypeptides influencing early physiologic processes such as decidualization, implantation, angiogenesis and maternal haemodynamics could contribute to the increased PE risk among women undergoing programmed FET cycles.

WIDER IMPLICATIONS

A better understanding of the critical roles of the secretory products of the CL during early pregnancy holds the promise of improving the efficacy and safety of ART based on programmed FET cycles.

Prorenin periconceptionally and in pregnancy: Does it have a physiological role?

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications.

Proteinase-activated receptor-2 (PAR2) on blood pressure and electrolyte handling in the late pregnant rat

NEW FINDINGS

What is the central question of this study? Pregnancy requires marked renal sodium and potassium retention and cumulative plasma volume expansion, in the setting of reduced blood pressure. Research in male rodents has shown that activation of PAR2 can produce peripheral vasodilatation, stimulate renal sodium chloride reabsorption and inhibit renal potassium secretion. Here, we investigate PAR2 activation in virgin and normal pregnant rats. What is the main finding and its importance? PAR2 expression and sensitivity to activation are increased in pregnancy. This implicates a possible role for PAR2 in supporting the renal/vascular adaptations of pregnancy required for normal maternal plasma volume expansion.

ABSTRACT

A healthy pregnancy involves renal and systemic haemodynamic adaptations, which allow renal sodium and potassium retention and cumulative plasma volume expansion, accompanied by a decline in blood pressure attributable to a reduction in the total peripheral vascular resistance. When these adaptations do not occur, pregnancy is compromised. The mechanisms permitting these opposing adaptations are largely unknown. Research in male rodents has shown that activation of PAR2 can produce peripheral vasodilatation, stimulate renal sodium chloride reabsorption and inhibit renal potassium secretion. Here, we investigate PAR2 activation in female virgin and normal late pregnant (LP) rats. We measured the mRNA expression of PAR2 in the renal cortex, outer medulla and inner medulla of virgin and LP rats using quantitative real-time PCR. We also measured in vivo blood pressure, natriuretic and kaliuretic responses to PAR2-activating peptide (SLIGRL-NH₂ ) in anaesthetized virgin and LP rats. We found that PAR2 mRNA was increased in the inner medulla of LP rats. We also found that LP rats had larger decreases in blood pressure and increases in net sodium retention compared with virgin rats. These findings suggest that pregnancy enhances sensitivity to the blood pressure-lowering and sodium-retaining effects of PAR2.

Prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances and birth outcomes: A longitudinal cohort with repeated measurements

BACKGROUND

Previous studies on perfluoroalkyl and polyfluoroalkyl substances (PFAS) showed inconsistent results when biological samples were collected in different time of pregnancy.

OBJECTIVES

To describe the change of PFAS concentration during pregnancy and to identify a sensitive window for adverse effects of PFAS on the fetus.

METHODS

A total of 255 pregnant women were selected from the Shanghai Birth Cohort (SBC). We quantified 10 PFAS with high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) in maternal plasma at three trimesters and cord blood at delivery. Multiple linear regression analyses were used to analyze the association between PFAS and birth outcomes, including birth weight, birth length, and head circumference.

RESULTS

The concentrations of most PFAS declined substantially during pregnancy. PFOS, PFNA, PFDA, PFUA and PFDoA were negatively related to birth length only in the first trimester. The coefficients and 95% confidence intervals (CI) of birth length change with a log-unit increase in PFOS, PFNA, PFDA, PFUS and PFDoA concentrations were -0.27 cm (-0.51, -0.02), -0.34 cm (-0.65, -0.03), -0.27 cm (-0.53, -0.01), -0.29 cm (-0.58, -0.01), and -0.54 cm (-1.00, -0.08), respectively. The effects were only observed for female fetuses. No association between PFAS and birth weight or head circumference was observed.

CONCLUSION

The concentrations of most PFAS in the maternal circulation declined during pregnancy. There were negative associations between several PFAS and birth length. The sensitive window of exposure appeared to be the first trimester. The association was stronger for female fetuses.

Development of a Gestational and Lactational Physiologically Based Pharmacokinetic (PBPK) Model for Perfluorooctane Sulfonate (PFOS) in Rats and Humans and Its Implications in the Derivation of Health-Based Toxicity Values

BACKGROUND

There is a great concern on potential adverse effects of exposure to perfluorooctane sulfonate (PFOS) in sensitive subpopulations, such as pregnant women, fetuses, and neonates, due to its reported transplacental and lactational transfer and reproductive and developmental toxicities in animals and humans.

OBJECTIVES

This study aimed to develop a gestational and lactational physiologically based pharmacokinetic (PBPK) model in rats and humans for PFOS to aid risk assessment in sensitive human subpopulations.

METHODS

Based upon existing PBPK models for PFOS, the present model addressed a data gap of including a physiologically based description of basolateral and apical membrane transporter-mediated renal reabsorption and excretion in kidneys during gestation and lactation. The model was calibrated with published rat toxicokinetic and human biomonitoring data and was independently evaluated with separate data. Monte Carlo simulation was used to address the interindividual variability.

RESULTS

Model simulations were generally within 2-fold of observed PFOS concentrations in maternal/fetal/neonatal plasma and liver in rats and humans. Estimated fifth percentile human equivalent doses (HEDs) based on selected critical toxicity studies in rats following U.S. Environmental Protection Agency (EPA) guidelines ranged from 0.08 to 0.91 μ g / kg  per day . These values are lower than the HEDs estimated in U.S. EPA guidance (0.51 - 1.6 μ g / kg  per day ) using an empirical toxicokinetic model in adults.

CONCLUSIONS

The results support the importance of renal reabsorption/excretion during pregnancy and lactation in PFOS dosimetry and suggest that the derivation of health-based toxicity values based on developmental toxicity studies should consider gestational/lactational dosimetry estimated from a life stage-appropriate PBPK model. This study provides a quantitative tool to aid risk reevaluation of PFOS, especially in sensitive human subpopulations, and it provides a basis for extrapolating to other per- and polyfluoroalkyl substances (PFAS). All model codes and detailed tutorials are provided in the Supplemental Materials to allow readers to reproduce our results and to use this model. https://doi.org/10.1289/EHP7671.

Prorenin periconceptionally and in pregnancy: Does it have a physiological role?

Pregnancy demands major cardiovascular, renal and endocrine changes to provide an adequate blood supply for the growing fetus. The renin-angiotensin-aldosterone system plays a key role in this adaptation process. One of its components, prorenin, is released in significant amounts from the ovary and uteroplacental unit. This review describes the sources of prorenin in the periconception period and in pregnancy, including its modulation by in-vitro fertilization protocols, and discusses its potential effects, among others focusing on preeclampsia. It ends with discussing the long-term consequences, even in later life, of inappropriate renin-angiotensin-aldosterone system activity in pregnancy and offers directions for future research. Ultimately, a full understanding of the role of prorenin periconceptionally and during pregnancy will help to develop tools to diagnose and/or prevent reproductive complications.

Environmental cadmium exposure induces fetal growth restriction via triggering PERK-regulated mitophagy in placental trophoblasts

Cadmium (Cd), an environmental toxicant, is positively associated with fetal growth restriction (FGR). However, the mechanism by which gestational exposure to Cd induces FGR remains unclear. This study designed in vitro and in vivo experiments to explore the role of placental mitophagy in Cd-impaired fetal growth. Based on our case-control study, we also investigated the association of placental mitophagy with reduced progesterone (P4) level and all-cause FGR. We firstly found environmental Cd exposure lowered the P4 content in maternal sera, placentae and amnioticfluids of mice. The level of three mitochondrial P4 synthases, including StAR, CYP11A1 and 3β-HSD, was also reduced in Cd-treated placentae. Furthermore, Cd triggered mitophagy, as determined by the degradation of two mitochondrial proteins HSP60 and COX IV, and the accumulation of co-localizations of TOM20 with LC3B or Parkin in placental trophoblasts. Correspondingly, Cd elevated mitochondrial Parkin level in placental trophoblasts. Mdivi-1, a mitophagy inhibitor, obviously attenuated Cd-induced reduction of placental P4 and FGR in mice. Moreover, mdivi-1 and Parkin siRNA (siR) markedly reversed Cd-caused P4 synthesis inhibition in human placental trophoblasts. Interestedly, the PERK/ATF4 signaling was activated in Cd-stimulated placental trophoblasts. PERK siR inhibited mitochondrial proteins degradation in Cd-stimulated placental trophoblasts. In particularly, mitophagy activation and P4 synthesis suppression occurred in small-for-gestational-age placentae based on our case-control study. Environmental Cd exposure induced FGR via activating PERK-regulated mitophagy and inhibiting P4 synthesis in placentaltrophoblasts. Furthermore, placental mitophagy was related to the reduced progesterone level and all-cause fetal growth restriction based on our case-control study. As above, placental mitophagy maybe the common mechanism of environmental toxicants-impaired fetal growth.

Environmental exposure to cadmium impairs fetal growth and placental angiogenesis via GCN-2-mediated mitochondrial stress

Cadmium (Cd), a well-known environmental pollutant, can lead to placental insufficiency and fetal growth restriction. However, the underlying mechanism is unknown. The purpose of our study is to explore the effect of Cd on placental angiogenesis and its mechanism using in vitro and in vivo models. Results found that gestational Cd exposure obviously decreased placental weight and impaired placental vascular development in mice. Correspondingly, Cd exposure evidently downregulated the expression of VEGF-A protein (a key indicator of angiogenesis) and progesterone receptor (PR) in placental trophoblasts. Further experiment showed that lentivirus PR overexpression reversed Cd-caused the reduction of VEGF-A level in human placental trophoblasts. In addition, Cd significantly reduced progesterone level, down-regulated the expression of key progesterone synthase (StAR, CYP11A1), and activated mitochondrial stress response and GCN-2/p-eIF2α signaling in placental trophoblasts. Additional experiment showed that GCN-2 siRNA pretreatment markedly alleviated Cd-activated mitochondrial stress response, restored Cd-downregulated the expression of CYP11A1, reversed Cd-reduced the level of progesterone and VEGF-A in human placental trophoblasts. Finally, our case-control study confirmed that impaired placental angiogenesis and reduced progesterone level occurred in all-cause small for gestational age placenta. Taken together, environmental exposure to Cd impairs fetal growth and placental angiogenesis via GCN-2-mediated mitochondrial stress.

Insulin-regulated aminopeptidase deficiency impairs cardiovascular adaptations and placental development during pregnancy

Insulin-regulated aminopeptidase (IRAP), an enzyme that cleaves vasoactive peptides including oxytocin and vasopressin, is suggested to play a role in pregnancy and the onset of preeclampsia. Our aim was to examine the contribution of IRAP to arterial pressure regulation and placental development during pregnancy in mice. Mean arterial pressure and heart rate were measured via radiotelemetry in 12-week-old female wild-type and IRAP knockout mice. Females were time-mated with males of the same genotype. Placentae were collected at embryonic day 18.5 for histological analysis. Basal heart rate was ∼40 bpm lower in IRAP knockout females compared with wild-type females. The increase in heart rate across gestation was greater in IRAP knockout females than wild-type females. Neither basal nor gestational mean arterial pressure was different between wildtype and IRAP knockout females. Urine output and water intake of IRAP knockout mice were ∼45% less than wild-type mice at late gestation. IRAP deficiency had no effect on fetal weight. Morphological assessment of placentae revealed that IRAP deficiency was associated with reduced labyrinth surface area and accumulation of glycogen in the junctional zone. Our data demonstrate that IRAP deficiency alters maternal fluid handling and impairs placental labyrinth expansion at late gestation, indicating that IRAP contributes to the normal adaptions to pregnancy.

Regulation of Uterine Spiral Artery Remodeling: a Review

Extravillous trophoblast remodeling of the uterine spiral arteries is essential for promoting blood flow to the placenta and fetal development, but little is known about the regulation of this process. A defect in spiral artery remodeling underpins adverse conditions of human pregnancy, notably early-onset preeclampsia and fetal growth restriction, which result in maternal and fetal morbidity and mortality. Many in vitro studies have been conducted to determine the ability of growth and other factors to stimulate trophoblast cells to migrate across a synthetic membrane. Clinical studies have investigated whether the maternal levels of various factors are altered during abnormal human pregnancy. Animal models have been established to assess the ability of various factors to recapitulate the pathophysiological symptoms of preeclampsia. This review analyzes the results of the in vitro, clinical, and animal studies and describes a nonhuman primate experimental paradigm of defective uterine artery remodeling to study the regulation of vessel remodeling.