Placental Features Research Articles

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.

Timing of distal villous fetal vascular malperfusion in the placenta: The clinical significance and placental features

Timing of distal villous fetal vascular malperfusion in the placenta: The clinical significance and placental features

Effects of per- and polyfluoroalkyl substances on placental features in the New Hampshire Birth Cohort Study

Effects of per- and polyfluoroalkyl substances on placental features in the New Hampshire Birth Cohort Study

The current state of the problem, clinical-pathogenetic approaches to the diagnosis and management tactics of fetal growth restriction

Fetal growth restriction is a common complication of pregnancy with a complex etiology and limited possibilities of diagnosis and treatment. The relevance of this difficult obstetric problem is determined by various published diagnostic criteria, relatively low detection rates, and limited options for prevention and treatment.Fetal growth restriction is defined as the inability of the fetus to reach its genetically determined growth potential, most often due to abnormal placentation. Forms of fetal growth restriction with early or late onset are distinguished based on the gestational age determined during prenatal ultrasound diagnosis. According to most recommendations, the 32nd week of pregnancy is set as the cut-off point for distinguishing between early and late onset fetal growth restriction.The definition underlying this classification is based on differences between these two phenotypes of fetal growth restriction in severity, natural history, Doppler findings, association with hypertensive complications, placental features, and management. It is important to distinguish two separate conditions: fetal growth restriction and small-for-gestational fetus, which differ in short-term and long-term perinatal outcomes.A fetus is defined as small for gestational age if the estimated weight or weight of the fetus at birth is below the 10th percentile. Fetal growth restriction is diagnosed if the estimated fetal weight is below the 3rd percentile or a combination of pathological blood flow in the umbilical arteries and/or uterine arteries in fetuses with an estimated weight below the 10th percentile. It can also occur in fetuses and newborns with a body weight above the 10th percentile.The need to distinguish between fetal growth restriction and small-for-gestational-age fetus is related to the fact that fetal growth restriction is the main cause of stillbirth, neonatal death, higher perinatal morbidity, as well as increased risk of diseases in adulthood.The article analyzes the approaches to differentiating fetal growth restriction from small growth retardation in terms of fetal gestation period and further increasing the accuracy of diagnosis, as well as the modern concept of pathogenesis, with an emphasis on oxidant stress as a key molecular mechanism of adverse outcomes. Appropriate interventions during pregnancy to reduce perinatal complications should include antenatal monitoring and drug therapy.

Evaluation of the effect of SARS-CoV-2 infection on Doppler ultrasound and placental findings of pregnant women: a systematic review and meta-analysis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect the human placenta and has been shown to have an adverse effect on Doppler ultrasound parameters and placental features. However, the specific effects of the SAS-CoV-2 infection on the fetal-placental unit in pregnant women remain unclear. The aim of this systematic review and meta-analysis was to evaluate the impact of SARS-CoV-2 infection on Doppler ultrasound and placental findings in pregnant women. A systematic search was conducted using four electronic databases (PubMed, Embase, Scopus, and Cochrane Library) to select publications published in peer-reviewed journals written in English. Odds ratios (ORs) were calculated, along with their 95% confidence intervals (CIs). Heterogeneity was assessed using Cochrane Q and I2 statistics and the appropriate P-value. The analysis used RevMan 5.3. This meta-analysis included 1,210 pregnant women from 10 case-control studies. SARS-CoV-2-infected pregnant women exhibited higher likelihoods of placental abnormalities (OR, 2.62; 95% CI, 1.66 to 4.13), aberrant Doppler values (OR, 1.95; 95% CI, 1.16 to 3.27), an abnormal cerebroplacental ratio (OR, 2.68; 95% CI, 1.52 to 4.75), altered fetoplacental circulation (OR, 1.56; 95% CI, 1.07 to 2.28), and increased placental thickness and placental venous lakes (OR, 1.85; 95% CI, 1.25 to 2.72). According to this meta-analysis, pregnant women infected with SARS-CoV-2 are more likely to experience altered Doppler ultrasonography parameters and placental abnormalities, including increased placental thickness, placental venous lakes, altered fetoplacental circulation, and cerebroplacental ratio. However, the limited number of case-control studies requires larger sample sizes to validate and enhance the evidence.

Severe COVID-19 in pregnant women: Analysis of placental features and perinatal outcomes.

Changes in placental features, such as maternal and fetal vascular malperfusion, are associated with SARS-CoV-2 infection. The anatomopathologic study of the placenta is crucial for understanding pregnancy and fetal complications. To that end, this study aimed to describe placental features and analyze the association between placental findings and perinatal outcomes in a cohort of pregnant women with severe COVID-19. This nested study within a prospective cohort study consisted of 121 singleton pregnant women with a diagnosis of severe COVID-19. Placental pathologic findings were described, and the associations between severe COVID-19 and clinical parameters and perinatal outcomes were assessed. The prevalence of maternal vascular malperfusion was 52.1%, followed by fetal vascular malperfusion at 21.5%, ascending intrauterine infections at 11.6%, and inflammatory lesions at 11.6%. Other lesions were observed in 39.7% of the placentas examined. Inflammatory lesions were an independent factor (P = .042) in 5-minute Apgar scores below 7. Ascending infection was associated with fetal death (P = .027). Maternal vascular malperfusion was the most prevalent placental feature in patients with severe COVID-19. Chorangiosis is associated with poor perinatal outcomes.

Step-by-step protocol for isolating the entire repertoire of human first trimester placental cells

Correct placental development and function are essential for adapting the mother to the ongoing pregnancy and the wellbeing of the growing fetus; however, underlying processes are still poorly understood. Only limited structural and cellular placental features are shared among species hence requiring reliable human in-vitro models. Recently established trophoblast stem cell and organoid models significantly improved placental research; however, the human placenta constitutes a multi-cellular organ with tightly orchestrated, cellular and molecular networks between trophoblasts (TBs) and villous core cells (VCCs) vital for correct placentation. The establishment of co-culture models is accordingly the logical consequence to investigate TB and VCC interactions, but first requires efficient purification of ideally donor-matched placental cell types. We herein present a meticulously-tailored protocol based on four sequential digestion steps (d-steps) with varying enzyme compositions and digestion mode and length, gently releasing cells layer-by-layer from human first trimester placentae (8 – 9th week of gestation). Using immunofluorescence and flow cytometry, we analyzed the tissue fragments and digestion solutions after every d-step and collected data on individual digestion progress as well as cell viability, counts, and specifications. D-step 1 revealed a significantly low viability and was mainly composed of syncytial fragments, extravillous trophoblasts EVTs, and maternal leukocytes. D-step 2 and 3, comprising high viability predominantly contained TBs (90 – 99 %) with a significant enrichment of EVTs in d-step 2 and an almost pure villous cytotrophoblast (vCTB) population in d-step 3. D-step 4 finally enabled isolating fetal VCCs consisting of endothelial cells, fibroblasts, and Hofbauer cells. Interestingly, maternal leukocytes were detected in d-step 1 and 2 but completely absent from d-step 3 and 4 revealing pure fetal cell populations. In sum, we present a detailed guideline for stepwise isolating selected placental cell types suitable for further studies and co-culture models investigating TB and VCC interactions involved in early placental development.

Morphological and clinical findings in placentas and newborns with a history of tobacco, alcohol, and other substance abuse during pregnancy.

Exposure to toxins during pregnancy is the main modifiable behavior that affects the placenta and, consequently, the fetus. In particular, smoking is a recognized risk factor for negative outcomes. Our study pretended to examine gross and microscopic placental features in women who reported exposure to tobacco, alcohol, or other psychoactive substances. In this observational case-control study, we collected 706 placentas to assess precise substance exposure histological-interaction features of in the placenta. We examined gross and microscopic placental features, and then recorded maternal and newborn clinical conditions. We found that 4.8% of mothers admitted to consumption of some type of (harmful) substance. The most common pre-existing maternal condition was obesity (20.3%); predominant complications included amniotic infection (32.3%), urinary tract infection (14.5%) and hypertensive disorders of pregnancy (14.5%). In newborns, we discovered positive associations as respiratory distress syndrome. Macroscopically, exposed mothers had heavier placentas, more true knots, and single umbilical artery; microscopically, they were more likely to exhibit fetal vascular malperfusion (FVM). Until our present study, no research linked umbilical cord defects to toxic substance exposure; our study results do confirm association with adverse outcomes in neonates and alterations in the neuro-cardio-placental circuit through FVM. The results are confirming the importance of this modifiable risk factor and how its presence may potentially affect the course of pregnancy, as well as the health of both mother and child.

448 Deformable Medial Modeling to Generate Novel Shape Features of the Placenta Using Automated versus Manual Segmentations

OBJECTIVES/GOALS: In this study, we implemented deformable medial modeling as a morphometric approach in first trimester placentas to characterize morphometric differences between fully automated and manual segmentations. METHODS/STUDY POPULATION: Twenty placentas from singleton pregnancies between 11-14 weeks’ gestation were manually and automatically segmented from 3D ultrasound volumes. Automated segmentations were produced by a trained convolutional neural network pipeline. Dice overlap scores and volumes were computed between manual and automated segmentations. Deformable medial modeling was applied to both manual and automated segmentations to produce the following metrics: maternal and chorionic surface areas (SA), thickness, circumference, and diameter along the generated medial surface. Placental non-planarity was also determined as the greatest medial surface height difference. A paired t-test and simple linear regression was performed between manual and automated segmentations for each shape metric. RESULTS/ANTICIPATED RESULTS: Mean placental volume measurements between manual and automated segmentations were similar, with a percent difference of 3.28% and a mean Dice overlap score of 0.85 ± 0.07. There were strong, statistically significant (p <0.01) linear correlations with chorionic and maternal SA, SA difference, thickness, circumference, medial surface diameter, and medial surface height difference. No significant differences were noted with chorionic SA, thickness, circumference, maximum medial surface diameter, or medial surface height difference. However, statistically significant differences (p <0.01-0.03) were noted in maternal SA, SA difference, and mean medial surface diameter. Despite these differences, mean percent difference for all morphometric parameters was less than or equal to 10%. DISCUSSION/SIGNIFICANCE: A deformable medial model evaluate unique global and regional shape placental features with highly correlated values between manual versus automated placental segmentations. However, clinical studies are needed to determine if minor differences would impact the clinical utility of these features as potential indicators of placental function.

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation.

This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations. This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians. Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, vs negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion. Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

Insights into Placental Pathology: Analyzing Patterns and Fetal Outcomes in 205 Livebirths at Bugando Medical Centre, Mwanza, Tanzania

Background: The placenta facilitates vital nutrient exchange between fetus and mother, offering insights into fetal and maternal health. Despite its significance, research on placental histopathology in Tanzania is scarce. This study investigates placental features, maternal factors, and their impact on fetal outcomes at Bugando Medical Centre from January to May 2022. Methods: This 5-month cohort study included 205 mothers delivering at BMC. Fetal outcomes were evaluated at birth and after seven days, with maternal characteristics recorded at delivery. Participants were from the twenty-eighth week of gestation, excluding those with intrauterine fetal death or multiple pregnancies. Data on placental histology, maternal factors, and fetal outcomes were collected systematically, while statistical analysis employed STATA version 15, utilizing descriptive statistics. Results: In this study of 205 placentas, participants had a median age of 29 years and a mean gestational age of 38 weeks. Histopathological patterns were present in 61% of placentas, with acute inflammation (22%) and maternal vascular malperfusion (20.8%) being most common. Favorable outcomes were observed in 81% of newborns, while 19% experienced poor outcomes, including 1.9% early neonatal deaths. Most placental lesions were mild (53.6%), with severe pathology in 2.9% of cases. Acute inflammation correlated with various admission reasons, especially neonatal sepsis (60%). Maternal vascular lesions were associated with prematurity (63.6%) and birth asphyxia (40%). Chronic inflammation was more prevalent among low-birth-weight infants (18.8%), while very low birth weight was common in cases of maternal vascular lesions (68.8%). Conclusion: The majority of placentas showed normal or mild pathology, associated with positive fetal outcomes. Further research is needed to understand placental changes and their impact on maternal-fetal health.

CT angiography for characterization of advanced placenta accreta spectrum: indications, risks, and benefits.

Placenta accreta spectrum disorder (PASD) encompasses various types of abnormal placentation in which chorionic villi directly adhere to or invade the myometrium. The incidence of PASD has dramatically risen in the US over the past 3 decades owing to the increased rates of patients undergoing cesarean sections. While PASD remains a significant cause of maternal morbidity and mortality, accurate prenatal identification and characterization of PASD is associated with improved outcomes. Although ultrasound is the first-line imaging modality in the evaluation of PASD, with MRI serving as an adjunct, computed tomography angiography (CTA) may also offer unique diagnostic advantages in cases of advanced PASD by providing superior visualization of placental and abdominopelvic vasculature and enabling the creation of comprehensive vascular maps to roadmap complex surgical interventions. This paper represents the first evaluation of CTA as a diagnostic tool and operative planning aid in this context. Appropriate indications and diagnostic advantages of CTA in this setting are reviewed, and key multimodal imaging features of normal and abnormal placentation are highlighted.

Automated detection of microscopic placental features indicative of maternal vascular malperfusion using machine learning

IntroductionHypertensive disorders of pregnancy (HDP) and fetal growth restriction (FGR) are common obstetrical complications, often with pathological features of maternal vascular malperfusion (MVM) in the placenta. Currently, clinical placental pathology methods involve a manual visual examination of histology sections, a practice that can be resource-intensive and demonstrates moderate-to-poor inter-pathologist agreement on diagnostic outcomes, dependant on the degree of pathologist sub-specialty training. MethodsThis study aims to apply machine learning (ML) feature extraction methods to classify digital images of placental histopathology specimens, collected from cases of HDP [pregnancy induced hypertension (PIH), preeclampsia (PE), PE + FGR], normotensive FGR, and healthy pregnancies, according to the presence or absence of MVM lesions. 159 digital images were captured from histological placental specimens, manually scored for MVM lesions (MVM- or MVM+) and used to develop a support vector machine (SVM) classifier model, using features extracted from pre-trained ResNet18. The model was trained with data augmentation and shuffling, with the performance assessed for patch-level and image-level classification through measurements of accuracy, precision, and recall using confusion matrices. ResultsThe SVM model demonstrated accuracies of 70 % and 79 % for patch-level and image-level MVM classification, respectively, with poorest performance observed on images with borderline MVM presence, as determined through post hoc observation. DiscussionThe results are promising for the integration of ML methods into the placental histopathological examination process. Using this study as a proof-of-concept will lead our group and others to carry ML models further in placental histopathology.

Influence of maternal psychological distress during COVID-19 pandemic on placental morphometry and texture

The Coronavirus Disease 2019 (COVID-19) pandemic has been accompanied by increased prenatal maternal distress (PMD). PMD is associated with adverse pregnancy outcomes which may be mediated by the placenta. However, the potential impact of the pandemic on in vivo placental development remains unknown. To examine the impact of the pandemic and PMD on in vivo structural placental development using advanced magnetic resonance imaging (MRI), acquired anatomic images of the placenta from 63 pregnant women without known COVID-19 exposure during the pandemic and 165 pre-pandemic controls. Measures of placental morphometry and texture were extracted. PMD was determined from validated questionnaires. Generalized estimating equations were utilized to compare differences in PMD placental features between COVID-era and pre-pandemic cohorts. Maternal stress and depression scores were significantly higher in the pandemic cohort. Placental volume, thickness, gray level kurtosis, skewness and run length non-uniformity were increased in the pandemic cohort, while placental elongation, mean gray level and long run emphasis were decreased. PMD was a mediator of the association between pandemic status and placental features. Altered in vivo placental structure during the pandemic suggests an underappreciated link between disturbances in maternal environment and perturbed placental development. The long-term impact on offspring is currently under investigation.

Identifying a dynamic transcriptomic landscape of the cynomolgus macaque placenta during pregnancy at single-cell resolution.

Supporting healthy pregnancy outcomes requires a comprehensive understanding of the cellular hierarchy and underlying molecular mechanisms in the primate placenta during gestation. Here, we present a single-cell transcriptome-wide view of the cynomolgus macaque placenta throughout gestation. Bioinformatics analyses and multiple validation experiments suggested that placental trophoblast cells exhibited stage-specific differences across gestation. Interactions between trophoblast cells and decidual cells also showed gestational stage-dependent differences. The trajectories of the villous core cells indicated that placental mesenchymal cells were derived from extraembryonic mesoderm (ExE.Meso) 1, whereas placental Hofbauer cells, erythrocytes, and endothelial cells were derived from ExE.Meso2. Comparative analyses of human and macaque placentas uncovered conserved features of placentation across species, and the discrepancies of extravillous trophoblast cells (EVTs) between human and macaque correlated to their differences in invasion patterns and maternal-fetal interactions. Our study provides a groundwork for elucidating the cellular basis of primate placentation.

Analysis of placental pathology after COVID-19 by timing and severity of infection

COVID-19 during pregnancy can have serious effects on pregnancy outcomes. The placenta acts as an infection barrier to the fetus and may mediate adverse outcomes. Increased frequency of maternal vascular malperfusion has been detected in the placentas of patients with COVID-19 compared with controls, but little is known about how the timing and severity of infection affect placental pathology. This study aimed to examine the effects of SARS-CoV-2 infection on placental pathology, specifically whether the timing and severity of COVID-19 affect pathologic findings and associations with perinatal outcomes. This was a descriptive retrospective cohort study of pregnant people diagnosed with COVID-19 who delivered between April 2020 and September 2021 at 3 university hospitals. Demographic, placental, delivery, and neonatal outcomes were collected through medical record review. The timing of SARS-CoV-2 infection was noted, and the severity of COVID-19 was categorized on the basis of the National Institutes of Health guidelines. The placentas of all patients with positive nasopharyngeal reverse transcription-polymerase chain reaction COVID-19 testing were sent for gross and microscopic histopathologic examinations at the time of delivery. Nonblinded pathologists categorized histopathologic lesions according to the Amsterdam criteria. Univariate linear regression and chi-square analyses were used to assess how the timing and severity of SARS-CoV-2 infection affected placental pathologic findings. This study included 131 pregnant patients and 138 placentas, with most patients delivered at the University of California, Los Angeles (n=65), followed by the University of California, San Francisco (n=38) and Zuckerberg San Francisco General Hospital (n=28). Most patients were diagnosed with COVID-19 in the third trimester of pregnancy (69%), and most infections were mild (60%). There was no specific placental pathologic feature based on the timing or severity of COVID-19. There was a higher frequency of placental features associated with response to infection in the placentas from infections before 20 weeks of gestation than that from infections after 20 weeks of gestation (P=.001). There was no difference in maternal vascular malperfusion by the timing of infection; however, features of severe maternal vascular malperfusion were only found in the placentas of patients with SARS-CoV-2 infection in the second and third trimesters of pregnancy, not in the placentas of patients with COVID-19 in the first trimester of pregnancy. Placentas from patients with COVID-19 showed no specific pathologic feature, regardless of the timing or severity of the disease. There was a higher proportion of placentas from patients with COVID-19-positive tests in earlier gestations with evidence of placental infection-associated features. Future studies should focus on understanding how these placental features in SARS-CoV-2 infections go on to affect pregnancy outcomes.

Placental lesions associated with stillbirth by gestational age, according to feature importance: Results from the stillbirth collaborative research network

IntroductionPrevious studies have identified lesions commonly found in placentas associated with stillbirth but have not distinguished across a range of gestational ages (GAs). The objective of this study was to identify lesions associated with stillbirths at different GAs by adapting methods from the chemical machine learning field to assign lesion importance based on correlation with GA. MethodsPlacentas from the Stillbirth Collaborative Research Network were examined according to standard protocols. GAs at stillbirth were categorized as: <28 weeks (extreme preterm stillbirth [PTSB]), 28–33′6 weeks (early PTSB), 34–36′6 weeks (late PTSB), ≥37 weeks (term stillbirth). We identified and ranked the most discriminating placental features, as well as those that were similar across GA ranges, using Kernel Principal Covariates Regression (KPCovR). ResultsThese analyses included 210 (47.2%) extreme PTSB, 85 (19.1%) early PTSB, 62 (13.9%) late PTSB, and 88 (19.8%) term stillbirths. When we compute the KPCovR, the first principal covariate indicates that there are four lesions (acute funisitis & nucleated fetal red blood cells found in extreme PTSB; multifocal reactive amniocytes & multifocal meconium found in term stillbirth) that distinguish GA ranges among all stillbirths. DiscussionThere are distinct placental lesions present across GA ranges in stillbirths; these lesions are identifiable using sophisticated feature selection. Further investigation may identify histologic changes across gestations that relate to fetal mortality.

Topography-based feature extraction of the human placenta from prenatal MR images.

Magnetic resonance imaging (MRI) has gained popularity in the field of prenatal imaging due to the ability to provide high quality images of soft tissue. In this paper, we presented a novel method for extracting different textural and morphological features of the placenta from MRI volumes using topographical mapping. We proposed polar and planar topographical mapping methods to produce common placental features from a unique point of observation. The features extracted from the images included the entire placenta surface, as well as the thickness, intensity, and entropy maps displayed in a convenient two-dimensional format. The topography-based images may be useful for clinical placental assessments as well as computer-assisted diagnosis, and prediction of potential pregnancy complications.

Rigour and reproducibility in perinatal and paediatric epidemiologic research using big data.

Rigour and reproducibility in perinatal and paediatric epidemiologic research using big data.

Effect of Parity on Placental Histopathology Features in Singleton Live Births Following IVF.

The aim of this study was to evaluate the effect of parity (primipara vs multipara) on the histopathology of the placenta in singleton live births following in vitro fertilization. We conducted a retrospective cohort study evaluating data of all IVF resulted live births from one university affiliated hospital during 2009-2017. All patients had the placenta sent for pathological evaluation. Exclusion criteria were history of miscarriage or elective termination of pregnancy, abnormal uterine cavity findings, previous uterine surgery, in vitro maturation cycles, gestational carrier cycles, oocyte recipient cycles, preimplantation genetic diagnosis cycles, and multiple pregnancies. The outcomes measured included anatomical, inflammation, vascular malperfusion, and villous maturation placental features. A multivariate analysis was conducted to adjust the results for factors potentially associated with placental pathology features. A total of 395 live births were included in the final analysis and were allocated to the study groups according to parity: primipara (n = 273) and multipara (n = 122). After adjustment for potential confounding factors, multiparity was found to be significantly associated with delayed villous maturation (OR 4.9; 95% CI 1.2-19.8) and primiparity was significantly associated with maternal vascular malperfusion (OR 0.6; 95% CI 0.3-0.8). We showed that parity has an impact on placental histopathological changes which in turn may affect perinatal outcome.