Placental Histopathology and Pregnancy Outcomes in "Early" vs. "Late" Placental Abruption

Association of Ambient Air Pollution and Temperature Exposure with Placental Abruption: A Nested Case-Control Study Based on Live Birth Registrations

BACKGROUND

Placental abruption, a rare disorder of unclear etiology, lacks evidence to illustrate its relationship with exposure to air pollution and temperature.

OBJECTIVE

This study aimed to investigate the association between exposure to ambient pollutants and temperatures and placental abruption to identify susceptible time windows and subpopulations.

METHODS

A nested case-control study was based on a live birth registration database in Chongqing, the largest Chinese municipality in China, from 2018 to 2022. The placental abruption cases were each matched with four controls by maternal age at delivery, gestational week, gravidity, parity, and delivery date. Six ambient pollutants [particulate matter (PM) with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ), PM with aerodynamic diameter ≤ 10 μ m (PM 10 ), NO 2 , CO, O 3 , and SO 2 ] and temperature were estimated using machine learning algorithms. A conditional logistic regression model analyzed associations of exposure to air pollution and temperature with placental abruption in five time windows (prepregnancy, the entire pregnancy, and each of the 3 trimesters). Stratification analyses were applied to examine potential modifiers including gravidity, parity, mothers' residential area (urban/rural), pandemic experience, and delivery season.

RESULTS

After data quality control, 798 cases were identified and matched with 3,192 controls. An exposure relationship was identified between NO 2 during the pregnancy period and placental abruption (p < 0.001 ). In comparison with the first quartile level of NO 2 , the odds ratios (ORs) of abruption associated with exposure to the second, third, and fourth quartile levels of NO 2 were 1.42 [95% confidence interval (CI): 1.03, 1.96], 1.90 (95% CI: 1.30, 2.76), and 2.27 (95% CI: 1.39, 3.71), respectively. The association for NO 2 exposure existed in the 3 trimesters but not prepregnancy. Exposure to locally extreme low temperatures (< fifth percentile) in the third trimester was associated with increased risks of abruption (OR = 3.68 ; 95% CI: 1.67, 8.08) in comparison with locally moderate temperatures (25th-75th percentile). Stratified analysis showed no statistical significances within the effect modifiers.

DISCUSSION

Based on a large-scale live birth record, the study suggested that exposure to air pollutants, mainly NO 2 , during pregnancy may be a substantial risk factor for placental abruption. https://doi.org/10.1289/EHP14714.

Obstetric and neonatal outcomes in clinically diagnosed placental abruption with and without placental histopathologic confirmation-A retrospective study

OBJECTIVE

Placental abruption is a major obstetrical complication bearing potentially life-threatening consequences. Though the diagnosis of placental abruption is a clinical one, the nonspecific nature of common presenting symptoms, mainly vaginal bleeding and contractions, pose a challenge, and the contribution of placental pathology has been debated. In this study, we assessed the clinical significance of related placental lesions by comparing obstetric and neonatal outcomes among cases of placental abruption with versus without supporting histopathologic placental lesions.

METHODS

We retrospectively analyzed placental abruption cases diagnosed during an 8-year period at a single tertiary center. Maternal, neonatal, and placental outcomes were compared between cases of placental abruption with versus without histopathologic placental lesions. The primary outcome was a composite of severe neonatal morbidity and included 1 ≤ of the following: seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, periventricular leukomalacia, necrotizing enterocolitis, blood transfusion or neonatal death.

RESULTS

A total of 305 clinical placental abruption cases were included: 95 in the placental abruption with histopathologic lesions group (31.3%) and 210 without such lesions (68.8%). The group with histopathologic lesions was characterized by higher rates of vaginal bleeding at presentation and prematurity (P = 0.012 and P < 0.001, respectively). Additionally, this group had substantially higher rates of composite severe neonatal outcomes (the primary outcome) (P = 0.005) and concurrent maternal vascular malperfusion lesions (P < 0.001).

CONCLUSION

Our findings shed light on the association between placental abruption-related histopathologic lesions and adverse obstetric and neonatal outcomes. Thus, histopathologic examination can be advocated in suspected placental abruption, as patients with related placental lesions may require closer follow-up in subsequent pregnancies.

Placental histopathological abnormalities in adverse obstetric outcomes: a retrospective cross-sectional study at Sultan Qaboos University Hospital

INTRODUCTION

Placenta is a vital organ with highly specialized functions. According to the Perinatal Section of the Pediatric Pathology Society, placental histopathological abnormalities are typically categorized into maternal vascular hypoperfusion, fetal thrombotic vasculopathy, and inflammatory lesions. This study aims to assess the placental histopathological abnormality results in relation to adverse obstetric outcomes and to investigate whether specific placental abnormalities are associated with particular adverse outcomes.

METHODS

A retrospective cross-sectional study was conducted between January 2017 and January 2020 including all women who were admitted to Sultan Qaboos University Hospital with an adverse obstetric outcome who met the inclusion criteria, and whose placentas were sent for histopathological examination.

RESULTS

A total of 191 women were included in the study. The most common adverse obstetric outcomes included preterm labor (25.1%), fetal growth restriction (FGR) (19.4%), preeclampsia and related complications (15%), placental abruption (14.1%), and chorioamnionitis (14%). 74% of women had abnormal placental findings. Among women with preterm labor, inflammatory lesions were present in 56.3% of cases (p = 0.006). Fetal thrombotic vasculopathy lesions were present in 13.5% of FGR cases (p = 0.037). In preeclampsia cases, maternal under perfusion lesions were present in 79% of cases (p = 0.013).

CONCLUSION

Placental histopathological examination is an important tool for assessing perinatal outcomes. Correlating placental findings with specific obstetrical conditions and adverse outcomes provides valuable information that can assist obstetricians in developing appropriate management plans for future pregnancies.

Ultrasound based radiomics model for assessment of placental function in pregnancies with preeclampsia

The goal of our research is to elucidate and better assess placental function in rats with preeclampsia through an innovative application of ultrasound-based radiomics. Using a rat model induced with L-NAME, we carefully investigated placental dysfunction via microstructural analysis and immunoprotein level assessment. Employing the Boruta feature selection method on ultrasound images facilitated the identification of crucial features, consequently enabling the development of a robust model for classifying placental dysfunction. Our study included 12 pregnant rats, and thorough placental evaluations were conducted on 160 fetal rats. Distinct alterations in placental microstructure and angiogenic factor expression were evident in rats with preeclampsia. Leveraging high-throughput mining of quantitative image features, we extracted 558 radiomic features, which were subsequently used to construct an impressive evaluation model with an area under the receiver operating curve (AUC) of 0.95. This model also exhibited a remarkable sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 88.7%, 91.5%, 90.2%, 90.4%, and 90.0%, respectively. Our findings highlight the ability of ultrasound-based radiomics to detect abnormal placental features, demonstrating its potential for evaluating both normative and impaired placental function with high precision and reliability.

Accelerated epigenetic clock aging in maternal peripheral blood and preterm birth

BACKGROUND

Epigenetic clocks use CpG DNA methylation to estimate biological age. Acceleration is associated with cancer, heart disease, and shorter life span. Few studies evaluate DNA methylation age and pregnancy outcomes. AgeAccelGrim is a novel epigenetic clock that combines 7 DNA methylation components.

OBJECTIVE

This study aimed to determine whether maternal biological aging (via AgeAccelGrim) is associated with early preterm birth.

STUDY DESIGN

A prospective cohort of patients with singleton pregnancies and at high risk of spontaneous preterm birth delivering at a tertiary university hospital were included in this study. Genome-wide CpG methylation was measured using the Illumina EPIC BeadChip (Illumina, Inc, San Diego, CA) from maternal blood samples obtained at <28 weeks of gestation. AgeAccelGrim and its 7 DNA methylation components were estimated by the Horvath DNA methylation age online tool. Positive values are associated with accelerated biological aging, whereas negative values are associated with slower biological aging relative to each subject's age. The primary outcome was preterm birth at <34 weeks of gestation (any indication). The secondary outcomes were preterm birth at <37 and <28 weeks of gestation. AgeAccelGrim was analyzed as a continuous variable and in quartiles. Exploratory analyses evaluated each of the 7 DNA methylation components included in the composite AgeAccelGrim. Data were analyzed by chi-square test, t test, rank-sum test, logistic regression (controlling a priori for maternal age, cell counts, low socioeconomic status, and gestational age at the time of sample collection), and Kaplan-Meier survival analyses. The log-rank test was used to test the equality of the survival functions.

RESULTS

Overall, 163 patients met the inclusion criteria. Of the patients, 48%, 39%, and 21% delivered at <37, <34, and <28 weeks of gestation, respectively. The median AgeAccelGrim was -0.35 years (interquartile range, -2.24 to 1.31) for those delivering at term. Those delivering preterm had higher AgeAccelGrim values that were inversely proportional to delivery gestational age (preterm birth at <37 weeks of gestation: +0.40 years [interquartile range: -1.21 to +2.28]; preterm birth at <34 weeks of gestation: +0.51 years [interquartile range: -1.05 to +2.67]; preterm birth at <28 weeks of gestation: +1.05 years [interquartile range: -0.72 to +2.72]). Estimated DNA methylation of the 7 epigenetic clock component values was increased among those with preterm birth at <34 weeks of gestation, although the differences were only significant for DNA methylation of plasminogen activation inhibitor 1. In regression models, AgeAcccelGrim was associated with an elevated risk of preterm birth with increasing magnitude for increasing severity of preterm birth. For each 1-year increase in the AgeAccelGrim value (ie, each 1-year increase in biological age compared with chronologic age), the adjusted odds of preterm birth were 11% (adjusted odds ratio, 1.11; 95% confidence interval, 1.00-1.24), 13% (adjusted odds ratio, 1.13; 95% confidence interval, 1.01-1.26), and 18% (adjusted odds ratio, 1.18; 95% confidence interval, 1.04-1.35) higher for preterm birth at <37, <34, and <28 weeks of gestation, respectively. Similarly, individuals with accelerated biological aging (≥75th percentile AgeAccelGrim) had more than double the odds of preterm birth at <34 weeks of gestation (adjusted odds ratio, 2.36; 95% confidence interval, 1.10-5.08) and more than triple the odds of preterm birth at <28 weeks of gestation (adjusted odds ratio, 3.89; 95% confidence interval, 1.61-9.38). The adjusted odds ratio for preterm birth at <37 weeks of gestation was 1.73 but spanned the null (adjusted odds ratio, 1.73; 95% confidence interval, 0.81-3.69). In Kaplan-Meier survival analyses, those in the highest AgeAccelGrim quartile delivered the earliest (log-rank P value of <.001).

CONCLUSION

Accelerated biological aging was associated with preterm birth among high-risk patients. Future research confirming these findings and elucidating factors that slow biological aging may improve birth outcomes.

The Placenta and Neonatal Encephalopathy with a Focus on Hypoxic-Ischemic Encephalopathy

Background: Placental examination is important for its diagnostic immediacy to correlate with maternal and/or fetal complications and parturitional difficulties. In a broader context, clinicopathologic studies of the placenta have addressed a range of pathogenetic questions that have led to conclusive and inconclusive results and interpretations. Methods: Recent standardized morphologic criteria and terminology of placental lesions have facilitated the ability to compare findings from studies that have focused on complications and outcomes of pregnancy. This review is an evaluation of recent studies on placental lesions associated with hypoxic-ischemic encephalopathy (HIE). Conclusion: No apparent consensus exists on whether it is fetal inflammation with the release of cytokines or chronic maternal and/or fetal vascular malperfusion is responsible for HIE with a lowering of the threshold for hypoxic ischemia. The counter argument is that HIE occurs solely as an intrapartum event. Additional investigation is necessary.

Placental abruption at near-term and term gestations: pathophysiology, epidemiology, diagnosis, and management

Placental abruption is the premature separation of the placenta from its uterine attachment before the delivery of a fetus. The clinical manifestations of abruption typically include vaginal bleeding and abdominal pain with a wide variety of abnormal fetal heart rate patterns. Clinical challenges arise when pregnant people with this condition present with profound vaginal bleeding, necessitating urgent delivery, especially when there is a concern for maternal and fetal compromise and coagulopathy. Abruption occurs in 0.6% to 1.2% of all pregnancies, with nearly half of abruption occurring at term gestations. An exposition of abruption at near-term (defined as the late preterm period from 34 0/7 to 36 6/7 weeks of gestation) and term (defined as ≥37 weeks of gestation) provides unique insights into its direct effects, as risks associated with preterm birth do not impact outcomes. Here, we explore the pathophysiology, epidemiology, and diagnosis of abruption. We discuss the interaction of chronic processes (decidual and uteroplacental vasculopathy) and acute processes (shearing forces applied to the abdomen) that underlie the pathophysiology. Risk factors for abruption and strengths of association are summarized. Sonographic findings of abruption and fetal heart rate tracings are presented. In addition, we propose a management algorithm for acute abruption that incorporates blood loss, vital signs, and urine output, among other factors. Lastly, we discuss blood component therapy, viscoelastic point-of-care testing, disseminated intravascular coagulopathy, and management of abruption complicated by fetal death. The review seeks to provide comprehensive, clinically focused guidance during a gestational age range when neonatal outcomes can often be favorable if rapid and evidence-based care is optimized.

The Association of Placental Abruption and Pediatric Neurological Outcome: A Systematic Review and Meta-Analysis

Placental histopathology provides insights, or "snapshots", into relevant antenatal factors that could elevate the risk of perinatal brain injury. We present a systematic review and meta-analysis comparing frequencies of adverse neurological outcomes in infants born to women with placental abruption versus without abruption. Records were sourced from MEDLINE, Embase, and the CENTRAL Trials Registry from 1946 to December 2019. Studies followed the PRISMA guidelines and compared frequencies of neurodevelopmental morbidities in infants born to pregnant women with placental abruption (exposure) versus women without placental abruption (comparator). The primary endpoint was cerebral palsy. Periventricular and intraventricular (both severe and any grades of IVH) and any histopathological neuronal damage were the secondary endpoints. Study methodologic quality was assessed by the Ottawa-Newcastle scale. Estimated odds ratios (OR) and hazards ratio (HR) were derived according to study design. Data were meta-analyzed using a random effects model expressed as pooled effect sizes and 95% confidence intervals. We included eight observational studies in the review, including 1245 infants born to women with placental abruption. Results of the random effects meta-analysis show that the odds of infants born to pregnant women with placental abruption who experience cerebral palsy is higher than in infants born to pregnant women without placental abruption (OR 5.71 95% CI (1.17, 27.91); I2 = 84.0%). There is no statistical difference in the odds of infants born to pregnant women with placental abruption who experience severe IVH (grade 3+) (OR 1.20 95% CI (0.46, 3.11); I2 = 35.8%) and any grade of IVH (OR 1.20 95% CI (0.62, 2.32); I2 = 32.3%) vs. women without placental abruption. There is no statistically significant difference in the odds of infants born to pregnant women with placental abruption who experience PVL vs. pregnant women without placental abruption (OR 6.51 95% CI (0.94, 45.16); I2 = 0.0%). Despite our meta-analysis suggesting increased odds of cerebral palsy in infants born to pregnant women with placental abruption versus without abruption, this finding should be interpreted cautiously, given high heterogeneity and overall poor quality of the included studies.

Obstetric outcomes following ovarian hyperstimulation syndrome in IVF - a comparison with uncomplicated fresh and frozen transfer cycles

Background

We aimed to assess the correlation between ovarian hyperstimulation syndrome (OHSS) in the early course of in vitro fertilization (IVF) pregnancies and obstetric outcomes.

Methods

We identified records of patients admitted due to OHSS following IVF treatment at our institution between 2008 and 2020. Cases were included if pregnancy resulted in a live singleton delivery (OHSS group). OHSS cases were matched at a 1:5:5 ratio with live singleton deliveries following IVF with fresh embryo transfer (fresh transfer group) and frozen embryo transfer (FET group), according to maternal age and parity. Computerized files were reviewed, and maternal, obstetric and neonatal outcomes compared.

Results

Overall, 44 OHSS cases were matched with 220 fresh transfer and 220 FET pregnancies. Patient demographics were similar between the groups, including body mass index, smoking and comorbidities. Gestational age at delivery, the rate of preterm births, preeclampsia and cesarean delivery were similar between the groups. Placental abruption occurred in 6.8% of OHSS pregnancies, 1.4% of fresh transfer pregnancies and 0.9% of FET pregnancies (p=0.02). On post-hoc analysis, the rate of placental abruption was significantly higher in OHSS pregnancies, compared with the two other groups, and this maintained significance after adjustment for confounders. Birthweights were 3017 ± 483, 3057 ± 545 and 3213 ± 542 grams in the OHSS, fresh transfer and FET groups, respectively (p=0.004), although the rate of small for gestational age neonates was similar between the groups.

Conclusions

OHSS in the early course of IVF pregnancies is associated with an increased risk of placental abruption.

Life After Amsterdam: Placental Pathology Consensus Recommendations and Beyond

The Amsterdam Placental Workshop Group Consensus Statement on Sampling and Definitions of Placental Lesions has become widely accepted and is increasingly used as the universal language to describe the most common pathologic lesions found in the placenta. This review summarizes the most salient aspects of this seminal publication and the subsequent emerging literature based on Amsterdam definitions and criteria, with emphasis on publications relating to diagnosis, grading, and staging of placental pathologic conditions. We also provide an overview of the recent expert recommendations on the pathologic grading of placenta accreta spectrum, with insights on their clinical context. Finally, we discuss the emerging entity of SARS-CoV2 placentitis.