PFAS alters placental arterial vasculature in term human placentae: A prospective pregnancy cohort study.

INTRODUCTION: Perfluoroalkyl substances (PFAS) are synthetic chemicals used in industrial and consumer goods that are widely detected in human populations and are associated with adverse health outcomes, including perinatal health risks and child health. One mechanism of influence may be the impact of PFAS exposure on placental structure and function. OBJECTIVES: The objective of this study is to investigate the relationship between maternal prenatal exposure to PFAS and measures of placental vascularization, and to assess whether changes in vascularization play a role in mediating the impact of PFAS on birth outcomes. METHODS: Using data from a prospective cohort study, we examined associations between second trimester PFAS (individually and as mixtures using Bayesian kernel machine regression) and placental arterial vasculature in term placentae (N = 158); secondarily we evaluated the degree to which alterations in placental arterial vasculature explained associations between PFAS exposure and birth outcomes. Placental arterial vasculature features were collected from arterial tracings of each placental image. RESULTS: In both linear regression and mixture models, natural log-transformed perfluorooctanoic acid concentrations were negatively associated with surface vasculature, indexed by the mean distance from arterial end point to perimeter (ß = -0.23, 95% CI: -0.41, -0.041); additionally, maximum arterial tortuosity was negatively associated with placental weight (ß = -0.19, 95% CI: -0.34, -0.051). There were no reliable differences in effect by fetal sex. DISCUSSION: The findings provide some of the first evidence of PFAS exposure shaping a key measure of placental vascular function, which may underlie the impact of PFAS on perinatal and child health risks.

Comparison of methanol fixation versus cryopreservation of the placenta for metabolomics analysis.

Methods for collection of placental tissue at room temperature for metabolic profiling are described. Specimens were excised from the maternal side of the placenta and immediately flash frozen or fixed and stored for 1, 6, 12, 24, or 48 h in 80% methanol. Untargeted metabolic profiling was performed on both the methanol-fixed tissue and the methanol extract. Data were analyzed using Gaussian generalized estimating equations, two sample t-tests with false discovery rate (FDR) corrections, and principal components analysis. Methanol-fixed tissue samples and methanol extracts had a similar number of metabolites (p = 0.45, p = 0.21 in positive vs. negative ion mode). In positive ion mode, when compared to flash frozen tissue, both the methanol extract and methanol-fixed tissue (6 h) had a higher number of metabolites detected (146 additional metabolites, pFDR = 0.020; 149 additional metabolites, pFDR = 0.017; respectively), but these associations were not found in negative ion mode (all pFDR ≥ 0.05). Principle components analysis demonstrated separation of the metabolite features in the methanol extract, but similarity between methanol-fixed tissue and flash frozen tissue. These results show that placental tissue samples collected in 80% methanol at room temperature can yield similar metabolic data to flash frozen specimens.

Examining associations between prenatal biomarkers of oxidative stress and ASD-related outcomes using quantile regression.

We examined associations between prenatal oxidative stress (OS) and child autism-related outcomes. Women with an autistic child were followed through a subsequent pregnancy and that younger sibling's childhood. Associations between glutathione (GSH), glutathione disulfide (GSSG), 8-oxo-deoxyguanine (8-OHdG), and nitrotyrosine and younger sibling Social Responsiveness Scale (SRS) scores were examined using quantile regression. Increasing GSH:GSSG (suggesting decreasing OS) was associated with minor increases in SRS scores (50th percentile ß: 1.78, 95% CI: 0.67, 3.06); no other associations were observed. Results from this cohort with increased risk for autism do not support a strong relationship between OS in late pregnancy and autism-related outcomes. Results may be specific to those with enriched autism risk; future work should consider other timepoints and biomarkers.

Criteria for placental examination for obstetrical and neonatal providers.

Pathologic examination of the placenta can provide insight into likely (and unlikely) causes of antepartum and intrapartum events, diagnoses with urgent clinical relevance, prognostic information for mother and infant, support for practice evaluation and improvement, and insight into advancing the sciences of obstetrics and neonatology. Although it is true that not all placentas require pathologic examination (although alternative opinions have been expressed), prioritization of placentas for pathologic examination should be based on vetted indications such as maternal comorbidities or pregnancy complications in which placental pathology is thought to be useful for maternal or infant care, understanding pathophysiology, or practice modifications. Herein we provide placental triage criteria for the obstetrical and neonatal provider based on publications and expert opinion of 16 placental pathologists and a pathologists' assistant, formulated using a modified Delphi approach. These criteria include indications in which placental pathology has clinical relevance, such as pregnancy loss, maternal infection, suspected abruption, fetal growth restriction, preterm birth, nonreassuring fetal heart testing requiring urgent delivery, preeclampsia with severe features, or neonates with early evidence of multiorgan system failure including neurologic compromise. We encourage a focused gross examination by the provider or an attendant at delivery for all placentas and provide guidance for this examination. We recommend that any placenta that is abnormal on gross examination undergo a complete pathology examination. In addition, we suggest practice criteria for placental pathology services, including a list of critical values to be used by the relevant provider. We hope that these sets of triage indications, criteria, and practice suggestions will facilitate appropriate submission of placentas for pathologic examination and improve its relevance to clinical care.

Comparison of trace element concentrations in paired formalin-fixed paraffin-embedded and frozen human placentae.

INTRODUCTION: There is increasing interest in measuring metals concentrations in human placentas to better understand physiology, disease, and toxic and diagnostic exposures. For these purposes, formalin-fixed paraffin embedded (FFPE) tissues obtained at clinical pathology examination represent a valuable potential store of well-characterized tissues for analysis. However, the limited data that exist comparing metal concentrations in FFPE tissue to recently collected frozen tissues paints a confusing picture, and there is no published data directly comparing frozen and FFPE placental villus tissues. METHODS: Paired samples of fresh frozen and FFPE tissue from 22 rapidly processed human singleton placentae were weighed and digested using standard clean laboratory procedures and subsequently analyzed for a suite of 13 metals using a PerkinElmer DRC II ICP-MS. The analytical results were compared using either a paired t-test or a sign test depending on data normality. RESULTS: Concentrations of metals (aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), gadolinium (Gd), mercury (Hg), manganese (Mn), lead (Pb), strontium (Sr), and zinc (Zn)) measured in both types of tissue preparations (frozen and FFPE) displayed a consistent range with other studies and did not display significantly different values from each of the paired specimens for any of the 13 specific metals analyzed. DISCUSSION: Within placentae, metals concentrations of measured trace, toxic and diagnostic elements (Al, As, Ba, Cd, Cr, Cu, Fe, Gd, Hg, Mn, Pb, Sr, and Zn) are consistent between FFPE and fresh placental villus tissue, without indications of systematic element loss or bias. FFPE from archived pathology specimens may offer an important and convenient alternative for measuring trace metals in human frozen placental tissues.

Placental morphology in association with autism-related traits in the EARLI study.

BACKGROUND: In prior work we observed differences in morphology features in placentas from an autism-enriched cohort as compared to those from a general population sample. Here we sought to examine whether these differences associate with ASD-related outcomes in the child. METHODS: Participants (n = 101) were drawn from the Early Autism Risk Longitudinal Investigation (EARLI), a cohort following younger siblings of children with autism spectrum disorder (ASD). ASD-related outcomes, including the Social Responsiveness Scale (SRS), Mullen Scales of Early Learning (MSEL) Early Learning Composite, and ASD diagnosis, were assessed at age 3. Crude and adjusted linear regression was used to examine associations between placental morphological features (parametrized continuously and in quartiles) and SRS and MSEL scores; comparisons by ASD case status were explored as secondary analyses due to the small number of cases (n = 20). RESULTS: In adjusted analyses, we observed a modest positive association between umbilical cord eccentricity, defined as the ratio of the maximum:minimum radius from the cord insertion point, and SRS scores (Beta = 1.68, 95%CI = 0.45, 2.9). Positive associations were also suggested between placental maximum thickness and cord centrality and SRS scores, though these were estimated with little precision. Associations between other placental morphological features and outcomes were not observed. CONCLUSIONS: Our analyses suggested a potential association between umbilical cord features and ASD-related traits, of interest as non-central cord insertion may reflect reduced placenta efficiency. Future studies with larger sample sizes are needed to further examine these and other placental features in association with ASD-related outcomes.

Placental pathology associated with maternal age and maternal obesity in singleton pregnancy.

OBJECTIVE: Maternal age, maternal obesity and neonatal sex dimorphism are known to affect pregnancy and neonatal outcome. However, the effects of these factors on specific placental pathology are less well-documented. STUDY DESIGN: Clinical information, placental pathology and neonatal data from singleton delivery were collected at our hospital in March 2020 to October 2021 and correlation studies were performed. RESULTS: A total 3,119 singleton placentas were examined between March 2020 and October 2021 in conjunction with clinical information and neonatal birth data. Advanced maternal age (>35) was significantly associated with a variety of pregnancy complications and placental pathology including preeclampsia/pregnancy induced hypertension (Pre/PIH), gestational diabetes mellitus (GDM2), intrauterine growth restriction (IUGR), and increased maternal body mass index (BMI) at delivery. Maternal obesity (BMI >30 at the time of delivery) was significantly associated with a variety of clinical features and placental pathology including PRE/PIH, GDM2 and decidual vasculopathy (mural arterial hypertrophy). No specific placental pathology was associated with neonatal sex except for more maternal inflammatory response (MIR, chronic deciduitis) in neonates of male sex. CONCLUSION: Maternal age and maternal obesity were associated with not only clinical complications of pregnancy and neonatal birth weight but also specific placental pathology. Understanding the effects of maternal and environmental factors will help improve pregnancy outcome.

Ultrasonographic study of umbilical cord twist direction during second trimester.

OBJECTIVE: To explore/study/evaluate the relationships among umbilical twist direction, the degree of umbilical twist and differences of umbilical arterial diameters (UAD). METHODS: All obstetric patients presenting for prenatal care of singleton fetuses between 18 and 25 weeks gestation to a single provider (MN) from 2015 to 2018 had detailed umbilical cord Doppler measurements. Data including the cord twist direction, degree of twist and number of twists per cord segment length, and the diameters of each UA (UAD) and the umbilical vein (UVD) were extracted from the records. UAs were described as right or left depending on their position at the fetal cord insertion. Three groups were identified: Group A: right UAD > left UAD and Group B: left UAD > right UAD Group C: equal UAD. The coiling index was calculated as the inverse of the length of cord required for one complete 360 degrees wrap of the UA around the cord. According to the difference of UADs, the variables of right and left UADs, the coiling index, and frequencies of umbilical twist direction were analyzed using non-parametric methods. RESULTS: 485 singleton fetuses and umbilical cords were examined. The value of the antenatal coiling index in cases with left UAD greater than right was 0.43 ± 0.16, which was significantly higher than 0.38 ± 0.16 with right UAD greater than left (p = .001). There were significant differences between the two groups in the values of right and left UAD, value of right minus left UAD, absolute value between right and left UAD, antenatal coiling index, antenatal coiling index due to umbilical twist direction and frequencies of cord twist direction. CONCLUSION: The direction of umbilical twist may be in part dependent on differences in diameters of the umbilical arteries, in addition to other fetal characteristics such as fetal movement, or handedness of fetus or mother, fetal hemodynamic forces and structure of muscles of umbilical vessels.

Differences in clinical and laboratory biomarkers for short and long-term respiratory outcomes in preterm neonates.

BACKGROUND: Pulmonary outcome of premature neonates has focused more on short-term than long-term respiratory morbidities. OBJECTIVE: Describe risk factors/biomarkers associated with short-term (bronchopulmonary dysplasia [BPD]) (supplemental oxygen use at 36 weeks postmenstrual age [PMA]) and longer-term (chronic respiratory morbidity [CRM]) (respiratory related symptoms, medications, medical/emergency visits, hospitalizations at 6-12 months corrected gestational age [CGA]) respiratory outcomes in a longitudinal cohort. DESIGN/METHODS: Neonates born at 24-29-week gestation were prospectively followed to 6-12-month CGA. Associations between clinical and laboratory risk factors/biomarkers of BPD and CRM were explored. RESULTS: Of 86 subjects, 94% survived. Outcomes were available for 89% at 36-week PMA (BPD present in 42% of infants) and 72% at 6-12-month CGA (CRM present in 47% of infants). For the 54 infants with known outcomes for both BPD and CRM, diagnoses were discordant in 41%. BPD was associated with lower birthweight and birthweight Z-score for GA, lower Apgar scores, more surfactant doses, higher SNAPPE-II scores, highest Day 1 inspired oxygen concentration, Day 7 oxygen use, prolonged ventilatory support, bacteremia, necrotizing enterocolitis, and treated patent ductus arteriosus. CRM was associated with lower Apgar scores, Day 7 oxygen use and higher urine vascular endothelial growth factor. Patterns of plasma and urine lipid oxidation products differed in the two outcomes. CONCLUSION: In this hypothesis generating and exploratory study, BPD and CRM were associated with different risk factors/biomarker patterns. Concordance between these two outcomes was weak. Strategies for reducing CRM should be studied in cohorts identified by appropriate early risk factors/biomarkers.

Cohort profile: Understanding Pregnancy Signals and Infant Development (UPSIDE): a pregnancy cohort study on prenatal exposure mechanisms for child health.

PURPOSE: Extensive research suggests that maternal prenatal distress is reliably related to perinatal and child health outcomes-which may persist into adulthood. However, basic questions remain regarding mechanisms involved. To better understand these mechanisms, we developed the Understanding Pregnancy Signals and Infant Development (UPSIDE) cohort study, which has several distinguishing features, including repeated assessments across trimesters, analysis of multiple biological pathways of interest, and incorporation of placental structure and function as mediators of child health outcomes. PARTICIPANTS: Women with normal risk pregnancies were recruited at <14 weeks gestation. Study visits occurred in each trimester and included extensive psychological, sociodemographic, health behaviour and biospecimen collection. Placenta and cord blood were collected at birth. Child visits (ongoing) occur at birth and 1, 6, 12, 24, 36 and 48 months of age and use standard anthropometric, clinical, behavioural, biological and neuroimaging methods to assess child physical and neurodevelopment. FINDINGS TO DATE: We recruited 326 pregnancies; 294 (90%) were retained through birth. Success rates for prenatal biospecimen collection were high across all trimesters (96%-99% for blood, 94%-97% for urine, 96%-99% for saliva, 96% of placentas, 88% for cord blood and 93% for buccal swab). Ninety-four per cent of eligible babies (n=277) participated in a birth examination; postnatal visits are ongoing. FUTURE PLANS: The current phase of the study follows children through age 4 to examine child neurodevelopment and physical development. In addition, the cohort participates in the National Institutes of Health's Environmental influences on Child Health Outcomes programme, a national study of 50 000 families examining early environmental influences on perinatal outcomes, neurodevelopment, obesity and airway disease. Future research will leverage the rich repository of biological samples and clinical data to expand research on the mechanisms of child health outcomes in relation to environmental chemical exposures, genetics and the microbiome.

Histopathology of the fetal inflammatory response to intra-amniotic pathogens.

Obstetric endorsement of the utility of placental histologic examination remains infrequent, especially from obstetricians who do not have a placental pathologist as part of their own local clinical care team. Placental pathologic examinations are viewed as useless if they do not provide answers to urgent clinical questions. Increasingly, however, it is appreciated that while placental analysis should be considered with regard to its longer term value; results can assess lifelong risks of a wide range of diseases that have been tied to prenatal exposures (e.g., [1]), including distinguishing sex-specific differences in those risks. (e.g., [2]) This review will focus solely on acute fetal (?) inflammation, more specifically, the fetal neutrophil responses in umbilical cord, chorionic plate vessels and to some degree, the fetal system as a whole. This histologic fetal inflammatory response is often the most readily accessible aspect of "FIR" piece of FIRS (the fetal inflammatory response syndrome). Some researchers have defined FIRS by a combination of both cytokine (especially IL-6) levels and the histopathologic FIR (Musilova et al., 2018) [3]. As we and others have noted, many histology based FIR cases, even those associated with neurodevelopmental outcomes such as cerebral palsy, are clinically silent.(e.g., [4]) Current clinical diagnostic criteria may have high specificity as they are very good at identifying non-FIR cases. However, that high specificity is coupled with very low specificity, identifying only 10% of FIR (Doty et al., 2018 Jul) [5]. Our aim is to provide a conceptual framework for the readers of the journal to better understand how to answer the following questions: What is a neutrophil and how is it important in FIR? What is the differential diagnosis for histologic FIR? How long has there been FIR? What secondary processes may have been recruited (and when) to contribute to the final pathology and pathophysiology of the given pregnancy?

SARS-CoV-2 can infect the placenta and is not associated with specific placental histopathology: a series of 19 placentas from COVID-19-positive mothers.

Congenital infection of SARS-CoV-2 appears to be exceptionally rare despite many cases of COVID-19 during pregnancy. Robust proof of placental infection requires demonstration of viral localization within placental tissue. Only two of the few cases of possible vertical transmission have demonstrated placental infection. None have shown placental expression of the ACE2 or TMPRSS2 protein, both required for viral infection. We examined 19 COVID-19 exposed placentas for histopathologic findings, and for expression of ACE2, and TMPRSS2 by immunohistochemistry. Direct placental SARS-CoV-2 expression was studied by two methods-nucleocapsid protein expression by immunohistochemistry, and RNA expression by in situ hybridization. ACE2 membranous expression in the syncytiotrophoblast (ST) of the chorionic villi is predominantly in a polarized pattern with expression highest on the stromal side of the ST. In addition, cytotrophoblast and extravillous trophoblast express ACE2. No ACE2 expression was detected in villous stroma, Hofbauer cells, or endothelial cells. TMPRSS2 expression was only present weakly in the villous endothelium and rarely in the ST. In 2 of 19 cases, SARS-CoV-2 RNA was present in the placenta focally in the ST and cytotrophoblast. There was no characteristic histopathology present in our cases including the two placental infections. We found that the placenta is capable of being infected but that this event is rare. We propose one explanation could be the polarized expression of ACE2 away from the maternal blood and pronounced paucity of TMPRSS2 expression in trophoblast.

Placental infarcts in the collaborative perinatal project: Variable associations infer variable constructs.

PURPOSE: Reproducible diagnoses of placental infarcts may permit more accurate assessment of their clinical significance. Using data across the 12 study sites of the National Collaborative Perinatal Project, we investigated the consistency of associations between infarct features with birthweight, placental weight and measures of placental "efficiency." METHODS: All delivered infants, live or stillborn, single or multiple, regardless of gestational age, were included. Pathologists scored infarcts by color (tan-white or "old" or pink-red "more recent"), size (cm), location (marginal or central), and total number. RESULTS: Incidence of any infarcts and distributions of specific features such as size, color (indicating age), locations and total numbers of infarcts were highly variable across sites, as were their associations with birthweight and placental efficiency. The most stable associations (consistent results across sites) of placental infarct scores were with placental size and/or other placental shape variables and with birthweight, but the number of significant associations ranged from 13 to 1. CONCLUSION: Given the extremes of infarct incidence within each site plus the variable correlations of infarct features with other placental and birth outcome measures, CPP infarct scores cannot be used as indicative of an underlying shared pathophysiologic construct. However, given the accumulating evidence that intrauterine stressors have the potential for lifelong impact on health, we propose that the infarct features and distinctions proposed are neither complex nor should they be jettisoned. Rather these measures should be clarified and refined. Only then can we understand the reported associations of placental infarcts with child and adult health outcomes.

A review of maternal prenatal exposures to environmental chemicals and psychosocial stressors-implications for research on perinatal outcomes in the ECHO program.

Exposures to environmental chemicals and psychosocial stressors during pregnancy have been individually associated with adverse perinatal outcomes related to birthweight and gestational age, but are not often considered in combination. We review types of psychosocial stressors and instruments used to assess them and classes of environmental chemical exposures that are known to adversely impact perinatal outcomes, and identify studies relevant studies. We discuss the National Institutes of Health's Environmental influences on Child Health Outcomes (ECHO) program that has combined existing longitudinal cohorts that include more than 50,000 children across the U.S. We describe future opportunities for investigators to use this important new resource for addressing relevant and critical research questions to maternal health. Of the 84 cohorts in ECHO, 38 collected data on environmental chemicals and psychosocial stressors and perinatal outcomes. The diverse ECHO pregnancy cohorts provide capacity to compare regions with distinct place-based environmental and social stressors.

Antibiotic therapy in acute gastroenteritis: a single-center retrospective cohort study.

BACKGROUND: Acute gastroenteritis (AGE) is a common reason for emergency department visits and hospitalizations. The role of antibiotics in AGE is unclear, as the current literature shows only a minor impact on the duration of symptoms and the overall clinical course. Our goal was to assess whether antibiotic therapy in patients with AGE affects the length of hospital stay (LOS). METHODS: In a retrospective study, we evaluated 479 patients admitted to the hospital with a diagnosis of AGE. The study compared the 219 patients (46%) treated with antibiotics to the remainder treated with supportive therapy. The diagnosis of AGE was made either clinically or based on imaging findings. The primary outcome of this study was to compare the LOS in days between both groups. RESULTS: Patients treated with antibiotics had a similar LOS to those treated with supportive therapy (2.62 vs. 2.66 days, P=0.77). Patients with presumed sepsis had a higher likelihood of receiving antibiotics compared to those without presumed sepsis (risk ratio 1.49, 62.5% vs. 41.95%; P<0.001). In this subgroup, patients who received antibiotics had a slightly shorter LOS than those who received only supportive therapy, but the difference was not statistically significant (2.09 vs. 2.54 days, P=0.69). CONCLUSION: We found no difference in the LOS for hospitalized patients with AGE treated with antibiotics when compared to supportive therapy. This calls into question the role of antibiotics in the management of AGE.

Gestational growth trajectories derived from a dynamic fetal-placental scaling law.

Fetal trajectories characterizing growth rates in utero have relied primarily on goodness of fit rather than mechanistic properties exhibited in utero. Here, we use a validated fetal-placental allometric scaling law and a first principles differential equations model of placental volume growth to generate biologically meaningful fetal-placental growth curves. The growth curves form the foundation for understanding healthy versus at-risk fetal growth and for identifying the timing of key events in utero.

Placental Studies for Child Development.

Research on children's psychological and behavioral development readily incorporates changing biological models and techniques. In this article, we suggest that, in response to increasing evidence of robust influences of prenatal exposures on children's neurodevelopment and mental and physical health, developmental science also needs to consider the placenta's role in development. We argue why placental mechanisms are plausible targets in developmental science, and suggest initial and practical steps toward integrating placenta markers and mechanisms into research on child development.