Massive chronic intervillositis associated with recurrent abortions

Chronic intervillositis of unknown etiology in patients with recurrent pregnancy loss: Impact on reproductive outcomes, treatment efficacy, and recurrence rates

OBJECTIVES

This study aimed to examine the influence of chronic intervillositis of unknown etiology (CIUE) on reproductive outcomes in patients with recurrent pregnancy loss (RPL), determine treatment effectiveness in future pregnancies, and estimate the CIUE recurrence rate.

MATERIALS AND METHODS

This retrospective study examined patients with RPL, categorizing them into CIUE and non-CIUE groups. Impact of CIUE on reproductive outcomes was assessed both cross-sectionally and longitudinally. A log-rank survival analysis was conducted to assess the effectiveness of various treatments on achieving ongoing pregnancies or live births following an initial episode of CIUE. Lastly, CIUE recurrence rate was evaluated.

RESULTS

A total of 394 patients were included in the study: 23 in the CIUE group and 371 in the non-CIUE group. No significant differences were observed between the groups regarding baseline characteristics. Adjusted logistic regression showed that patients with CIUE had higher odds of experiencing preterm birth compared to non-CIUE patients (odds ratio [OR] = 3.15; 95 % confidence interval [CI]: 1.07-9.22). With each additional pregnancy, the non-CIUE group had 75 % increased odds of achieving live birth (OR 1.75; 95 % CI: 1.49-2.06), while the CIUE group's increase was not significant (OR 1.32; 95 % CI: 0.86-2.05). Additionally, the odds of stillbirth associated with additional pregnancies increased by 85 % in the CIUE group (OR 1.85; 95 % CI: 1.03-3.36), yet not significant in the non-CIUE group (OR 1.14; 95 % CI: 0.90-1.45). CIUE-treated patients had higher odds of achieving live birth or ongoing pregnancy after 24 months (P = 0.0491). CIUE recurred in 21.7 % of patients.

CONCLUSION

In the RPL population, CIUE adversely affected the reproductive outcomes. Despite its high recurrence rate, prophylactic treatment showed potential in improving outcomes.

Caracteristics of women presenting with chronic histiocytic intervillositis during pregnancy: A case-control study

INTRODUCTION

Chronic Histiocytic Intervillositis (CHI) appears to be among the most severe placental diseases. Its rarity has limited our knowledge of the women in whom it occurs.

OBJECTIVE

To search for maternal characteristics linked to the existence of CHI, by first studying the current pregnancy included in the study, then their previous pregnancies.

MATERIAL AND METHODS

We conducted a monocentric case-control study between 2000 and 2020. CHI cases were diagnosed by microscopic examination of the placenta. "Low-risk" controls gave birth just before each case, whatever the outcome. "High-risk" controls benefited from placental microscopy immediately after the case examinations.

RESULTS

151 women were included in each group. CHI cases had twice as many previous pregnancies as both controls, but no more living children at home. Regarding obstetric history, fetal losses were significantly higher in CHI cases: compared to "low-risk" controls, there were more early miscarriages (20.0%, OR 2.6 [1.5;4.8]), late miscarriages (4.8%, OR 8.8 [1.1;187]) and in utero deaths (5.4%, OR 5.6 [1.7;19.8]). The risk of fetal loss does not appear to be increased in first pregnancies of CHI cases. However, differences appeared between cases and both "low-risk" and "high-risk" controls with a history of two previous miscarriages (21.7% vs 11.2%, p=0.009 or vs 9.6%, p=0.005) and the outcome of the second pregnancy (number of living children 59.7% vs 78.0%, p=0.033 or vs 63.0%, p=0.71), respectively.

CONCLUSION

Women with CHI have a more frequent history of pregnancy failure than other women. This excess fetal loss seems to occur only after the second pregnancy or after two previous miscarriages.

Placental chronic inflammatory histopathology and fetal growth in a cohort with universal placental examination

INTRODUCTION

Chronic placental inflammation is a routinely diagnosed group of placental lesions that reflect immunologic dysfunction of the mother, fetus, or both.

METHODS

Complete placental pathology examinations were performed for all term births at New York Presbyterian- Brooklyn Methodist Hospital from January 2010-August 2016. Diagnoses were blinded except to gestational age. CPI lesions were marked as chronic choriodeciduitis, decidual plasma cells, chronic inflammation of basal plate with anchoring villitis, and chronic villitis.

RESULTS

In this cohort of term pregnancies, 257 (11.6 %) males and 218 (9.8 %) females had ≥1 CPI lesions. Chronic villitis was the most common (319 or 14 %), with chronic choriodeciduitis, decidual plasma cells, and chronic inflammation of basal plate with anchoring villitis in 94 (4 %), 69 (3 %) and 170 (8 %), respectively. In males, chronic villitis was associated with lower gestational adjusted birthweight and had no association with placental weight. In females, chronic villitis was associated with lower gestational adjusted birthweight, but the effect became nonsignificant after adjustment for placental weight.

DISCUSSION

In summary, CPI lesions' incidence and association with birth weight vary by sex. Chronic villitis is associated with lower birthweight in females; this effect is completely mediated by placental weight. Chronic villitis showed a weak direct association of chronic villitis in males, but no association with lower placental weight in males. We suggest that differences between our results and previous publications reflect effects of sampling bias.

The severity of chronic histiocytic intervillositis is associated with gestational age and fetal weight

INTRODUCTION

Chronic histiocytic intervillositis (CHI) is a rare histopathological lesion in the placenta that is associated with poor reproductive outcomes. The intervillous infiltrate consists mostly of maternal mononuclear cells and fibrin depositions, which are both indicators for the severity of the intervillous infiltrate. The severity of the intervillous infiltrate as well as the clinical outcomes of pregnancy differ between cases. Our objective is to determine the relation between the severity of the intervillous infiltrate and the clinical outcomes of CHI.

METHODS

Cases of CHI were semi-quantitatively graded based on histopathological severity scores. Hereto, CD68 positive mononuclear cells were quantified, fibrin depositions visualized by both a PTAH stain and an immuohistochemical staining, and placental dysfunction was assessed via thrombomodulin staining.

RESULTS

This study included 36 women with CHI. A higher CD68 score was significantly associated with a lower birthweight. Loss of placental thrombomodulin was associated with lower gestational age, lower birthweight, and a lower placenta weight. The combined severity score based on CD68 and PTAH was significantly associated with fetal growth restriction, and the joint score of CD68 and fibrin was associated with birthweight and placental weight.

DISCUSSION

More severe intervillous infiltrates in CHI placentas is associated with a lower birth weight and placental weight. Furthermore, this study proposes thrombomodulin as a possible new severity marker of placental damage. More research is needed to better understand the pathophysiology of CHI.

Congenital Herpes Simplex Virus: A Histopathological View of the Placenta

Congenital Herpes simplex virus (HSV) infection is considered a common pregnancy pathology that is not always easy to diagnose. This study aimed to present the spectrum of placental histopathological lesions in pregnancies complicated by HSV infection. MEDLINE and Google Scholar databases were searched using the keywords "HSV" and "placental histopathology" up to June 20, 2022. Study inclusion required presenting placental histopathological anomalies in pregnant women diagnosed with HSV infection antenatally, during labor, or postnatally. Herein, we briefly present placental pathogenesis conditions, which have been correlated with congenital HSV infection, providing clinicians with a short review describing herpetic placental pathology.

Chronic histiocytic intervillositis (CHI): current treatments and perinatal outcomes, a systematic review and a meta-analysis

BACKGROUND

Chronic histiocytic intervillositis (CHI) is a rare placental lesion with a high recurrence rate and poor perinatal outcomes. There are currently limited guidelines regarding the diagnosis of this condition in the index pregnancy and treatment where recurrence is suspected.

OBJECTIVE

The primary objective of this systematic review and meta-analysis was to determine the perinatal outcomes of pregnancies affected by chronic histiocytic intervillositis and to what extent they can be improved with treatment. The secondary objective was to assess the relationship between CHI lesion severity and pregnancy loss.

METHODS

A systematic search of Ovid Embase, Web of Science, Science Direct, PubMed, Ovid Medline, Google Scholar and CINAHL was carried out. Case reports, cohort, case-control and randomised controlled trials (RCT) detailing the perinatal outcomes of CHI pregnancies, both treated and untreated, were included.

RESULTS

No RCTs were identified. However, in a review population of 659 pregnancies, with additional 7 in case reports, CHI treatments included aspirin, prednisone, prednisolone, low molecular weight heparin (LMWH), hydroxychloroquine and adalimumab. A descriptive synthesis of data found mixed results for treatments in relation to live birth, miscarriage and fetal growth restriction outcomes. Furthermore, quantitative synthesis of 38 pregnancies revealed a non-significant improvement in live birth rate with CHI targeted treatment (OR 1.79 [95% CI 0.33-9.61] (p=0.50), while meta-analysis of CHI severity in line with pregnancy loss, in a sample of 231 pregnancies, revealed lower odds of pregnancy loss with less severe lesions (OR: 0.17 [0.03-0.80], p=0.03).

CONCLUSIONS

This systematic review and meta-analysis reinforce notions surrounding the insufficient evidence for CHI treatment. It also strengthens previous hypotheses detailing the positive association between CHI lesion severity and odds of pregnancy loss. Aspirin, LMWH, prednisolone, hydroxychloroquine and adalimumab are candidates with varying levels of weak to moderate evidence supporting their use. Further prospective research is required to obtain robust evidence pertaining to treatment safety and efficacy and optimal drug regimes.

SYSTEMATIC REVIEW REGISTRATION

[website], identifier CRD42021237604.

Trophoblast damage with acute and chronic intervillositis: disruption of the placental barrier by severe acute respiratory syndrome coronavirus 2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was demonstrated in the placenta; however, the data on the prevalence of placental infection and associated histopathology are limited. To identify the frequency and features of SARS-CoV-2 involvement, we performed a clinicopathologic analysis of 75 placental cases from women infected at the time of delivery and 75 uninfected controls. Placental samples were studied with anti-SARS-CoV-2 immunohistochemistry and/or in situ hybridization. Positive results were confirmed by electron microscopy and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). During delivery, only one woman had symptoms of coronavirus disease 2019, six women reported previous symptoms, and 68 women were asymptomatic. All neonates tested negative for SARS-CoV-2 as per nasopharyngeal swab PCR results. Obstetric histories were unremarkable in 29 of 75 SARS-CoV-2-positive and 8 of 75 SARS-CoV-2-negative women. Placental examination was normal in 12 of 75 infected and 3 of 75 uninfected subjects, respectively. In the remaining cases, placental pathology correlated with obstetric comorbidities without significant differences between SARS-CoV-2-positive and SARS-CoV-2-negative women. SARS-CoV-2 was identified in one placenta of an infected, but asymptomatic, parturient. Viral staining was predominantly localized to the syncytiotrophoblast (STB) which demonstrated marked damage accompanied by perivillous fibrin deposition and mixed intervillositis. A significant decrease of viral titers was detected in the attached umbilical cord compared with the villous parenchyma as per qRT-PCR. SARS-CoV-2 is seldom identified in placentas of infected women. Placental involvement by the virus is characterized by STB damage disrupting the placental barrier and can be seen in asymptomatic mothers without evidence of vertical transmission.

Chronic Intervillositis of Unknown Etiology: Development of a Grading and Scoring System That Is Strongly Associated With Poor Perinatal Outcomes

Chronic intervillositis of unknown etiology (CIUE) is a rare placental disease characterized by intervillous infiltration of maternal macrophages and associated with poor pregnancy outcomes and a high risk of recurrence in subsequent pregnancies. Its pathophysiology remains unclear and prognostic factors have not yet been established. In addition, clear relationships between the histologic extent of lesions and the severity of perinatal outcomes have not been demonstrated. Our objectives were to validate a CIUE classification system based on the gradation of macrophagic infiltration of the intervillous space, and to attempt to correlate these results with perinatal outcomes. For this multicenter retrospective study, 3 pathologists reviewed all cases diagnosed with "intervillositis" between 1997 and 2018. Confirmed CIUE cases were semiquantitatively graded based on the percentage of macrophagic infiltrate in the intervillous space: grade 1 (5% to 10%), grade 2 (10% to 50%), and grade 3 (>50%). Multiple pregnancies and pregnancies with medical follow-up completed outside of the study centers were excluded. In total, 122 cases of CIUE in 102 patients were included in the study. Microscopic classification based on one criterion was easy to perform, and interobserver correlation was good. Grade 3 infiltration was strongly associated with poor perinatal outcomes and fetal growth restriction (P<0.0001). After delivery, only 16.1% of newborns from the grade 3 CIUE group were alive, compared with 59% from the grade 2 and 86.5% from the grade 1 group (P=0.0002). Recurrence risk was associated with CIUE gradation of the index case (P=0.004), with 95% of recurrent CIUE cases being from patients with grades 2 and 3 CIUE. In this study, conducted with the largest CIUE cohort to date, a classification based only on the degree of macrophagic infiltration of the intervillous space was validated, and this classification was shown to be strongly associated with poor perinatal outcomes and risk of recurrence.

Abnormal placental pathological findings and adverse clinical outcomes of oocyte donation

We sought to assess chronic inflammatory responses in patients who achieved pregnancy by oocyte donation and non-oocyte donation-assisted reproductive technology and delivered at The Ottawa Hospital. Data describing maternal health, obstetrical outcomes, neonatal outcomes, and placental pathology were collected and analyzed from electronic medical records. An increased frequency of adverse obstetrical outcomes was observed. In the oocyte donation-assisted reproductive technology group, placental pathology data demonstrated increased frequency of fetal vascular malperfusion (p = 0.02) and placenta accreta (p < 0.001), representing a chronic inflammatory response. Placental pathology reflecting dysregulated immune processes and vasculopathy is associated with oocyte donation.

Chronic Intervillositis of Unknown Etiology (CIUE): Prevalence, patterns and reproductive outcomes at a tertiary referral institution

INTRODUCTION

the objective of this study was to evaluate the incidence of Chronic Intervillositis of Unknown Etiology (CIUE) at our institution and to report on the pregnancy outcomes based on severity of lesions.

METHODS

retrospective cohort study including 29 889 perinatal specimens from 27 968 patients. The pathology database at our institution was queried for the keywords "intervillositis" and "CIUE" between February 2006 and April 2019. Histology was re-examined using a standardized diagnostic criterion to confirm diagnosis. Cases in which diagnosis was confirmed were categorized as low grade (5-49% intervillous space involvement) or high grade (≥50% involvement). Interventions and pregnancy outcomes were recorded.

RESULTS

The overall prevalence of CIUE is 0.17% (47 of 27 968 patients), with significantly higher prevalence in 1st trimester products of conception compared with 2nd and 3rd trimester specimens (0.38% vs 0.09%; p < 0.0001). A total of 97 specimens were initially diagnosed with chronic intervillositis. 56 out of 97 (57.7%) specimens met our diagnostic criteria for CIUE on review. Pregnancies with confirmed CIUE had significantly higher rates of pregnancy loss compared with pregnancies with chronic intervillositis not meeting our study criteria for CIUE (94% vs 71%; p = 0.003). Pregnancy loss between low grade (42.9%; 24 out of 56 cases of CIUE) and high grade (57.1%; 32 out of 56 cases) CIUE were not significantly different.

DISCUSSION

CIUE prevalence is low at 0.17%, but it is associated with pregnancy loss, particularly in the first trimester. High grade disease may be associated with worse pregnancy outcomes than low grade disease.

Adverse perinatal outcomes of chronic intervillositis of unknown etiology: an observational retrospective study of 122 cases

Our study aimed to assess perinatal outcomes and recurrence rate of Chronic Intervillositis of Unknown Etiology (CIUE). We conducted an observational retrospective study in a tertiary care university hospital in France from January 1, 1997 to July 31, 2018. 122 pregnancies (102 women) with CIUE were included. Cases of the Department of Histopathology placenta database were re-analysed independently by three pathologists specializing in fetal pathology. Diagnosis of CIUE was confirmed according to: (1) the presence of cellular infiltrate in the intervillous space, (2) ~ 80% of the mononuclear cells in the intervillous space positive for CD68, (3) infiltration occupying at least 5% of the intervillous space, and (4) no clinical or histopathological sign of infection. Outcomes of pregnancies with CIUE (miscarriages, stillbirths, terminations of pregnancy, live birth with or without prematurity or fetal growth restriction) and proportion of CIUE recurrence were analysed. The lost pregnancies comprised 17 (13.9%) miscarriages, 17 (13.9%) stillbirths, and 18 (14.8%) terminations of pregnancy. Of the 70 (57.4%) pregnancies that led to a live birth, 38 (54.3%) new-borns were premature and 50 (72.5%) exhibited fetal growth restriction. Among the 102 women, 23 subsequently became pregnant, half of whom (n = 11) developed recurrent CIUE. CIUE was associated with high rates of adverse perinatal outcomes, including pregnancy loss, fetal growth restriction, and preterm birth with a risk of recurrence nearly 50%.

Reproducibility of Grading in Chronic Intervillositis of Unknown Etiology

Chronic intervillositis of unknown etiology (CIUE) is a rare placental inflammatory process associated with pregnancy loss and recurrence. We conducted a quality assurance study to assess the diagnostic accuracy and reproducibility of CIUE grading at our institution. Hematoxylin and eosin-stained slides from 20 CIUE cases (31 slides) were reviewed by 7 perinatal pathologists in 2 sequential rounds. Reviewers were instructed to use the diagnostic criteria they were presently following for CIUE and to grade each slide according to the Rota scheme. In the first round, 20 slides were assessed. The diagnostic accuracy was 94%, the average percent agreement of Rota grade was 79%, and the Fleiss' kappa value for interobserver variability was 0.54. The results were reviewed by all pathologists with diagnostic and grading criteria agreed upon prior to the second round. In round 2, the remaining 11 slides were assessed. Diagnostic accuracy was 83%, the average percent agreement on Rota grade was 70%, and the Fleiss' kappa value for interobserver variability was 0.36. Overall, diagnostic accuracy was high and agreement on Rota grade was moderate. Group review did not appear to improve accuracy. Simplifying CIUE grading to a low-grade/high-grade scheme (<50% or ≥50%) might improve grading reproducibility.

Is chronic histiocytic intervillositis a severe placental disease? A case-control study

INTRODUCTION

Chronic histiocytic intervillositis (CHI) is a placental disease that has been associated with unfavorable obstetric outcomes in small, noncomparative series. The objective was to measure the excess risk of adverse obstetric outcomes associated with the discovery of CHI after birth.

METHODS

Retrospective single-center case-control study from 2000 through 2016. The case patients had a CHI diagnosis after a pathology analysis of the placenta. Two types of controls were defined for each case: low-risk control women were those who gave birth in our hospital immediately before each case patient, and the high-risk controls were the next women after each case for whom microscopic examination of the placenta was indicated.

RESULTS

We observed 111 cases of CHI during the study period. Compared with the 111 low-risk controls, the cases had a significantly higher frequency of late miscarriages (5.4 vs 0.0%, p < .03), small for gestational age (SGA) babies <3rd centile (70.4 vs 0.9%, p < .001, OR 140, 95% CI, 19.9-2800), and in utero deaths (35.1 vs 0.9%, p < .001, OR 59.6, 95% CI 8.5-1192), with significantly fewer children surviving to discharge (54.9 vs 99.1%, p < .001, OR 0.01, 95% CI, 0.00-0.08). All of these factors also differed significantly compared with the high-risk women (severe SGA: OR 3.7, 95% CI 1.9-7.0; in utero death: OR 4.1, 95% CI 1.9-8.7; children surviving to discharge: OR 0.27, 95% CI, 0.14-0.52).

DISCUSSION

Even compared with high-risk pregnancies, CHI is a severe placental disease associated with a substantial excess rate of late miscarriages, severe SGA and in utero death.

CD39 downregulation in chronic intervillositis of unknown etiology

Chronic intervillositis of unknown etiology (CIUE) is a rare placental lesion associated with infiltration of mononuclear inflammatory cells into the intervillous space, poor perinatal outcomes (intrauterine fetal demise or fetal growth restriction), and high rates of recurrence. CD39 is the ectonucleotidase that protects tissues from inflammatory stress and cell injury, which is localized on the surface of villi in normal placentas; however, its expression and role in CIUE are unknown. The aims of this retrospective study were to determine the expression of CD39 in CIUE and its significance in pregnancy outcomes. We compared the number of CD68- and CD3-positive cells, CD39 expression, and complement 4d (C4d) and fibrin deposition in placental tissues from patients with CIUE (n = 22) and gestational age-matched controls (n = 20), and between CIUE pregnancies with poor and good outcomes. The numbers of CD68- or CD3-positive cells were significantly higher (P < 0.0001), whereas CD39 expression on the surface of villi and endothelial cells of the stem villi was significantly lower in the CIUE group than that in controls (45% vs. 95%, P < 0.0001 and 77% vs. 96%, P < 0.001, respectively). C4d and fibrin deposition were also significantly increased in CIUE compared with those of controls. Furthermore, CD39 downregulation and the number of CD68 cells were strongly associated with poor pregnancy outcomes (P < 0.01 and P < 0.05, respectively), but other histological parameters (CD3, C4d, and fibrin) did not show this association. Our study suggests that CD39 downregulation is a useful marker of CIUE and is associated with poor pregnancy outcomes in patients with CIUE.

Placental pathologic lesions with a significant recurrence risk - what not to miss!

Here, we review three important placental pathologies with significant clinical implications and recurrence risks. They are, in order of most to least frequently seen, villitis of unknown etiology, chronic histiocytic intervillositis, and massive perivillous fibrin deposition (also known as maternal floor infarction). These entities occur in both preterm and term gestations and are observed more frequently with maternal and obstetric disorders including prior pregnancy loss, hypertension/preeclampsia, and autoimmune disease. They are associated with, and probably the cause of, significant perinatal morbidity and mortality including intrauterine growth restriction, fetal and neonatal demise, and fetal/neonatal neurocompromise (seizures and cerebral palsy). All three entities have high recurrence risks, with recurrence rates ranging from 34 to 100%. The histologic features of villitis of unknown etiology, chronic histiocytic intervillositis, and massive perivillous fibrin deposition are described herein. We discuss the clinical associations and suggest the subsequent clinical and pathological evaluation. Hypotheses as to the biology of these lesions are reviewed.

Towards standardized criteria for diagnosing chronic intervillositis of unknown etiology: A systematic review

Chronic intervillositis of unknown etiology (CIUE) is a poorly understood, relatively rare condition characterized histologically by the intervillous infiltration of mononuclear cells in the placenta. Clinically, CIUE is associated with poor pregnancy outcome (e.g., impaired fetal growth, preterm birth, fetal death) and high risk of recurrence in subsequent pregnancies. Because CIUE is not defined consistently, it is essential to clearly define this condition. We therefore review the published definitions of CIUE. In addition, we provide an overview of the reviewed histopathological and maternal characteristics, obstetric features, and pregnancy outcomes. Medical publication databases were searched for articles published through February 2017. Eighteen studies were included in our systematic review. The sole inclusion criterion used in all studies was the presence of intervillous infiltrates. Overall, CIUE was characterized by adverse pregnancy outcome. Miscarriage occurred in 24% of cases, with approximately half of these miscarriages defined as late. Impaired growth was commonly observed, 32.4% of pregnancies reached term, and the live birth rate was 54.9%. The high recurrence rate (25.1%) of the intervillous infiltrates in subsequent pregnancies underscores the clinical relevance of CIUE, the need for increased awareness among pathologists and clinicians, and the need for further research. Criteria for the diagnosis of CIUE are proposed and a Delphi study could be used to resolve any controversy regarding these criteria. Future studies should be designed to characterize the full clinical spectrum of CIUE.

Chronic histiocytic intervillositis in three consecutive pregnancies in a single patient: Differing clinical results and pathology according to treatment used

Chronic histiocytic intervillositis (CHI) is an extremely rare pathological condition but is strongly associated with severe obstetric complications and has a high recurrence rate. The management of this condition has not yet been established. We describe herein the occurrence of CHI in the late second-third trimester in each of three consecutive pregnancies in a single patient with four previous consecutive early miscarriages. In this patient, each of the three complicated pregnancies was managed with one of the following, respectively: low-dose aspirin; heparin plus low-dose aspirin; and prednisolone plus low-dose aspirin. CHI was histologically confirmed in all three pregnancies, but the clinical results and pathology (e.g. extent of histiocytic infiltration) in each pregnancy clearly differed with treatment. Both combination treatments eventuated in a live birth. Immunosuppressive therapy seemed to produce better clinical results by restricting the extent of the affected areas. The elevated alkaline phosphatase associated with the CHI was assumed to have no clinical prognostic value.

Successful pregnancy following treatment of recurrent chronic histiocytic intervillositis

Chronic histiocytic intervillositis (CHI) is a rare placental lesion associated with adverse obstetric outcomes and high recurrence rate. We report a case of six consecutive pregnancies in one woman, where CHI was detected following an intrauterine death in the fifth pregnancy, after being missed in four earlier losses. The successful sixth pregnancy was treated with a combination of immunosuppressive and antithrombotic agents. While low-molecular-weight heparin (LMWH) and aspirin had been shown to improve pregnancy outcome in recurrent pregnancy loss, there was limited evidence of improved outcome in CHI. It has been suggested that CHI may result from a maternal immunological process and there have been a few reports of the use of corticosteroids because of this possibility, though without convincing evidence of efficacy. We too tried a corticosteroid, in combination with LMWH and aspirin. Comparative histopathological analysis of the placentae supported post-treatment effectiveness of our intervention strategy.

Stillbirth and intrauterine fetal death: role of routine histopathological placental findings to determine cause of death

OBJECTIVES

Placental abnormalities are a common cause of death in stillbirth, ranking second only to unexplained deaths, though there is wide variation in the proportion attributed to placental disease. In clinical practice, interpretation of the significance of placental findings is difficult, since many placental features in stillbirths overlap with those in live births. Our aim was to examine objectively classified placental findings from a series of > 1000 autopsies following intrauterine death in order to evaluate the role of placental histological examination in determining the cause of death.

METHODS

As part of a larger study evaluating several aspects of autopsy findings in intrauterine death, a dedicated database was used to collate antenatal and postmortem examination details for all cases examined between 2005 and 2013 at two tertiary specialist centers in London, UK. Histological findings for placentas were evaluated in relation to the final cause of death.

RESULTS

Among 1064 intrauterine deaths, 946 (89%) cases had the placenta submitted for examination as part of the autopsy. Of these, 307 (32%) cases had the cause of death assigned to abnormalities of the placenta, cord or membranes. Around one third of stillbirths (≥ 24 weeks) had some isolated placental histological abnormality identified, many of uncertain significance, a significantly greater proportion than in cases of second-trimester intrauterine fetal demise (P < 0.0001). The cause of death was ascending infection in 176/946 (19%) cases, peaking at 22 weeks' gestation, with significantly more black mothers having ascending infection compared with other ethnicities (P < 0.0001). Maternal vascular malperfusion was the largest category of placental abnormalities in stillbirth, with peak prevalence in the early third trimester. There were 18 (2%) cases with specific histological abnormalities, including chronic histiocytic intervillositis and massive perivillous fibrin deposition.

CONCLUSIONS

Placental pathologies represent the largest category of cause of intrauterine death. Placental histological examination is the single most useful component of the autopsy process in this clinical setting. A minority of cases are associated with specific placental pathologies, often with high recurrence rates, that can be diagnosed only on microscopic examination of the placenta. Many deaths remain unexplained, although placental histological lesions may be present which are of uncertain significance. A rigorous, systematic approach to placental pathology research and classification may yield better understanding of the significance of placental findings and reduce the rate of unexplained intrauterine deaths. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Maternal Floor Infarction and Massive Perivillous Fibrin Deposition

Maternal floor infarction (MFI) and massive perivillous fibrin deposition (MPVFD) are pathologically overlapping placental disorders with characteristic gross and shared light microscopic features of excessive perivillous deposition of fibrinoid material. Although rare, they are associated with high rates of fetal growth restriction, perinatal morbidity and mortality, and risks of recurrence with fetal death. The cause of the extensive fibrinoid deposition is unknown, but evidence supports involvement of maternal alloimmune or autoimmune mechanisms. This article presents an updated discussion of features, placental histopathologic differential diagnosis, possible causes, clinical correlates, and adverse outcomes of the MFI/MPVFD spectrum.

Significance of C4d Immunostaining in Placental Chronic Intervillositis

Deposition of the complement split product C4d is a phenomenon studied extensively as a marker for complement activation in antibody-mediated transplant rejection. C4d also is observed in placental disease processes including spontaneous abortion, infarct, and villitis of unknown origins. Massive chronic intervillositis is a rare placental abnormality associated with increased risk of growth restriction, fetal death, and recurrent fetal loss. In this study, we evaluated C4d immunostaining in placentas with accumulation of intervillous monocytes with and without villitis. Archived placentas from Kosair Children's Hospital (Louisville, KY) and Seattle Children's Hospital (Seattle, WA) were selected and divided into 4 groups, 16 cases of intervillositis with complicated pregnancy, 15 cases of uncomplicated intervillositis, 20 cases of complicated villitis, and 13 cases of uncomplicated villitis, all with varying degrees of monocytic cells in the intervillous space. Representative specimen blocks were immunohistochemically stained for C4d. The percentage of positive staining of the microvillous surface of the syncytiotrophoblast was scored by five pathologists, and the following consensus score was determined: 0  =  0% to 5%; 1  =  5% to 25%; 2  =  25% to 75%; and 3 ≥ 75%. C4d immunostain localized to the microvillous border of syncytiotrophoblast in many of the placentas. C4d staining was more strongly associated with intervillositis than with villitis (odds ratio: 6.3; confidence interval: 2.1-18.7; P  =  0.001).

Chronic villitis of unknown etiology and massive chronic intervillositis have similar immune cell composition

INTRODUCTION

Chronic villitis of unknown etiology (CVUE) and massive chronic intervillositis (MCI) are placental lesions associated with infiltration of mononuclear cells in the chorionic villi and the intervillous spaces, respectively. It is not well known whether immune cells in CVUE and MCI have similar phenotypic characteristics.

METHODS

A cross-sectional study of third trimester placentas was conducted to identify immune cell subpopulations in CVUE and MCI (n = 17/group). CVUE was diagnosed with H&E staining and antibody to CD3 in serial sections; and MCI, by the presence of massive infiltration of mononuclear cells in the intervillous spaces. Immune cells, ICAM-1 expression and nuclear factor κB (NF-κB) activation were determined immunohistochemically.

RESULTS

CVUE and MCI showed similar infiltrates, mainly CD68+ and CD3+ cells. Most cells (>80%) were CD45RB+, and one third were CD45RO+ in both lesions. There were slightly more CD8+ than CD4+ cells in both CVUE and MCI. More than 90% of cells in CVUE and MCI were ICAM-1+ with NFκB nuclear localization. Syncytiotrophoblast ICAM-1 expression was significantly (p < 0.001) higher in MCI (mean of 81.0; range of 71.6-86.0) than in CVUE (52.4; 36.4-59.4) or normal placentas (0.2; 0.0-0.6). Both, failure of physiologic transformation of spiral arteries and placental atherosclerosis-like lesions of atherosis were significantly more frequent in MCI than in CVUE or normal placentas (p = 0.044 and p = 0.007, respectively).

DISCUSSION

These finding suggest that MCI and CVUE have very similar infiltration of immune cells although MCI has more severe placental lesions.

Chronic histiocytic intervillositis: outcome, associated diseases and treatment in a multicenter prospective study

Introduction: In this prospective multicenter study, we aimed to describe (1) the outcome of pregnancy in the case of previous chronic histiocytic intervillositis (CHI), (2) the immunological findings and associated diseases, (3) the treatments, and (4) the factors associated with pregnancy loss.

METHODS

We prospectively included all patients with a prior CHI with ongoing pregnancy between 2011 and 2013.

RESULTS

Twenty-four women (age 34±5 years) were included in this study. An autoimmune disease was present in seven (29%) cases. Twenty-one prospective pregnancies were treated. The number of live births was more frequent comparatively to the previous obstetrical issues (16/24 versus 24/76; p=0.003). Most of the pregnancies were treated (88%), whereas only 13% of previous pregnancies were treated (p<0.05). No difference was found with respect to the pregnancy outcome in the different treatment regimens. In univariate analyses, a prior history of intrauterine death and intrauterine growth restriction and the presence of CHI in prospective placentas were associated with failure to have a live birth.

DISCUSSION

In this multicenter study, we show the frequency of the associated autoimmune diseases in CHI, as well as the presence of autoantibodies without characterized autoimmune disease. The number of live births increased from 32% to 67% in the treated pregnancies. Despite the treatment intervention, the risk of preterm delivery remained at 30%. Last, we show that the recurrence rate of an adverse pregnancy outcome persisted at 30% despite treatment intervention.

CONCLUSION

CHI is associated with high recurrence rate and the combined regimen seems to be necessary, in particular, in the presence of previous intrauterine death.

An immunological basis for chronic histiocytic intervillositis in recurrent fetal loss

PROBLEM

Chronic histiocytic intervillositis (CHIV) is a rare type of placental pathology that is associated with reproductive loss at all gestational ages. The aim of the study was to investigate the relationship between the severity of CHIV and the outcome of pregnancy and to compare the immune response between CHIV patients and controls to explore an immunological origin of CHIV.

METHOD OF STUDY

Microscopic slides were reviewed and scored according to a previously published grading system in 30 pregnancies of 22 CHIV patients. Partner-specific mixed lymphocyte reactions, cytotoxic T-lymphocyte precursor frequencies (CTLpf), and anti-HLA antibodies were determined in four patients and seven controls.

RESULTS

Higher CHIV scores are associated with worse pregnancy outcome. CHIV patients demonstrated a higher CTLpf against their partner compared to non-complicated pregnancies (P = 0.03). The CTLpf was extremely high in 75% of the patients. Antipaternal HLA antibodies were only present in 75% of the CHIV patients compared to none of the controls (P = 0.02).

CONCLUSION

CHIV scores seem to be associated with the severity of adverse pregnancy outcome. High antipaternal cellular (T-cell) and humoral (B-cell) response to partner-specific CTLpf and the presence of anti-HLA antibodies directed to the partner suggest an immunologic origin of CHIV.

Villitis of Unknown Etiology and Massive Chronic Intervillositis

Villitis of unknown etiology (VUE) is a common lesion affecting from 6.6% to 33.8% of third-trimester placentas. VUE needs to be distinguished from villitis of infectious etiology, most commonly cytomegalovirus and syphilis. Clinically, this lesion is associated with intrauterine growth retardation, intrauterine fetal demise, fetal neural impairment, maternal alloimmune and autoimmune disease, and maternal hypertension. It has a tendency to recur in subsequent pregnancies. Massive chronic intervillositis (MCI), also known as chronic histiocytic intervillositis, is a rare lesion that has an unclear relationship with VUE. MCI is associated with recurrent abortions.

Neonatal alloimmune thrombocytopenia associated with massive chronic intervillositis: a case report and review of the literature

Neonatal alloimmune thrombocytopenia (NAIT) presents as isolated thrombocytopenia in a normal neonate as a result of destruction of fetal platelets by maternal antibodies against paternally derived human platelet antigens. Neonatal alloimmune thrombocytopenia affects 0.1% of births, with maternal antibodies crossing the placenta as early as 14 weeks' gestation. Few reports describe placental histopathological changes occurring in NAIT cases. We present a case of NAIT associated with massive chronic intervillositis, a rare entity occurring in 0.06% to 0.8% of reviewed 2nd- and 3rd-trimester placentas; to our knowledge, this is the 1st report of such an association.

Specific infiltration pattern of FOXP3+ regulatory T cells in chronic histiocytic intervillositis of unknown etiology

INTRODUCTION

Chronic histiocytic intervillositis of unknown etiology (CIUE) is a rare placental lesion characterized by an intervillous mononuclear inflammatory infiltrate of maternal origin. Although the mechanism and origin of these lesions are currently not understood, they appear to be related to an immune conflict between mother and fetus cells.

AIM

To clarify the inflammatory cell profile and evaluate the T regulatory lymphocyte (Treg) status in CIUE.

MATERIALS AND METHODS

All cases of CIUE that occurred over an 8-year period were analyzed using immunohistochemistry.

RESULTS

The inflammatory profile of CIUE was characterized by a clearly predominant component of histiocytic cells (80% ± 6.9) associated with some T cells (24% ± 5.7). The ratio of CD4+ versus CD8+ T cells was close to 1. This profile differs from infectious disease and chronic histiocytic villitis, the main differential diagnoses of CIUE. As for normal pregnancies most regulatory T cells were localized in the decidua basalis. Nevertheless, their appearance was also noted in the intervillous space. In both the intervillous space and the deciduas the number of Tregs gradually increased from grade 1 to 3.

CONCLUSION

We found that CIUE is associated with an increase in Treg lymphocytes in the decidua basalis and the intervillous space. Contrary to previously published data on human miscarriage, this result appears to be specific to CIUE and would support the hypothesis of an immunopathological disorder for CIUE.

Chronic histiocytic intervillositis with cytomegalovirus placentitis in a case of hydrops fetalis

Chronic histiocytic intervillositis (CHI) is an infrequent inflammatory placental disorder associated with unfavorable pregnancy outcomes and a high rate of recurrence. This disorder is thought to reflect a maternal delayed hypersensitivity response to fetal antigen(s) in placental tissue. We report a case of a 20-week-gestation hydropic fetus in which the placenta showed chronic histiocytic intervillositis with cytomegalovirus placentitis. Immunophenotyping studies supported a delayed hypersensitivity response. This is the first report of these two diseases co-occurring, raising the possibility of a relationship between chronic histiocytic intervillositis and infection. Chronic histiocytic intervillositis may represent an idiosyncratic immune response, in this case to cytomegalovirus.

CD68 Immunostaining in the Evaluation of Chronic Histiocytic Intervillositis

Context.—Chronic histiocytic intervillositis is an uncommon and poorly recognized lesion associated with poor perinatal outcomes, including intrauterine growth retardation and stillbirth. It has a high recurrence rate.

Objective.—To evaluate utility of CD68 immunostaining in the evaluation of chronic histiocytic intervillositis.

Design.—Institutional review board–approved retrospective review was performed. Cases were selected from the departmental archives of University Hospital, Newark, New Jersey, between 2002 and 2009. Controls were from second-trimester pregnancies with chromosomal abnormalities or multiple severe anomalies.

Results.—There were 9 cases and 11 controls. The mean CD68+ count per high-power field for the cases was 88 ± 23 (range, 51–180) and for the controls, 8 ± 5 (range, 0–24), P &lt; .001.

Conclusions.—This study establishes a range for histiocyte counts in chronic histiocytic intervillositis and pregnancies without chronic histiocytic intervillositis, and suggests that CD68 staining may have utility in the diagnosis, particularly for nonperinatal pathologists, who may be less familiar with this lesion.

Chronic intervillositis of the placenta: a systematic review

OBJECTIVE

Chronic intervillositis of the placenta is known to be associated with poor reproductive outcome and a high risk of recurrence. The aims of the present study were to quantify the risk of recurrence of chronic intervillositis in subsequent pregnancies, to explore if there are possible interventions and to assess the success of interventions.

METHODS

Systematic review of published literature using published guidelines.

RESULTS

No randomised controlled trials were identified. Sixty-one papers, published between 1977 and 2009 were identified after abstract screening but only 6 studies could be included in the systematic review. From the 6 selected studies, 69 pregnancies at gestational age of 14 weeks or over, with a histopathologic diagnosis of chronic intervillositis were available for analysis. The rate of intrauterine growth restriction in the study population was 66.7%, the overall rate of livebirth was 53.6%. In 16/20 (80.0%) cases recurrence of CI was confirmed at histopathology. The livebirth rate reported with treatment was 30.8% against 58.9% without treatment (RR=0.47, 95% CI=0.2-1.1). This difference was not statistically significant.

CONCLUSIONS

Chronic intervillositis has a high (80.0%) recurrence risk. In pregnancies reaching 14 weeks, the chance of a livebirth is 53.6%. The livebirth rate reported with treatment was 30.8% against 58.9% without treatment (RR=0.47, 95% CI=0.2-1.1). This difference was not statistically significant. Intervention with drug therapy is of no demonstrable benefit, and may even be harmful.

Placental pathology in egg donor pregnancies

OBJECTIVE

To determine placental pathology and immune response at the maternal-fetal interface in pregnancies conceived by IVF via egg donation compared with nondonor IVF pregnancies.

DESIGN

Retrospective case-control study.

SETTING

Academic medical center.

PATIENT(S)

The study population included 20 egg donor and 33 nondonor IVF pregnancies of >24 weeks' gestation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Perinatal complications (gestational hypertension, abruption, preterm delivery, cesarean section), microscopic features indicating an immune response and trophoblast damage, and characterization of inflammatory cells using immunohistochemistry.

RESULT(S)

There was an increase in gestational hypertension and preterm delivery in egg donor pregnancies. Dense fibrinoid deposition in the basal plate with severe chronic deciduitis containing significantly increased numbers of T helper and natural killer cells were demonstrated in egg donor placentas. Trophoblast damage was also increased in the preterm egg donor group.

CONCLUSION(S)

There are significant histological and immunohistochemical differences between the placentas of egg donor and nondonor IVF pregnancies. The increased immune activity and fibrinoid deposition at the maternal-fetal interface of egg donor pregnancies could represent a host versus graft rejection-like phenomenon.

Chronic intervillositis of unknown etiology (CIUE): relation between placental lesions and perinatal outcome

OBJECTIVES

To evaluate perinatal outcome of pregnancies complicated by chronic intervillositis of unknown etiology (CIUE) and to study the relation between extent of such placental histological lesions and clinical expression.

STUDY DESIGN

Descriptive and retrospective study including all cases of CIUE diagnosed between 2000 and 2006 in the university hospital of Toulouse (France). Perinatal outcome was evaluated according to the extent of placental lesions assessed by semi-quantitative graduation.

RESULTS

Twenty pregnancies complicated by CIUE were included (14 patients). Three pregnancies were prematurely interrupted spontaneously during the first trimester. Perinatal outcome of the remaining 17 pregnancies beyond 22 WG was: 4 intrauterine fetal deaths, 3 terminations of pregnancy for early and severe intrauterine growth restriction (IUGR), and 10 live births (58.8%). All fetal deaths, 82.3% of pregnancies beyond 22 WG and 70% of live births were growth restricted. Severe intervillositis with massive fibrinoid deposition was associated with a severe perinatal prognosis whereas focal forms had a best evolution. The rate of recurrence was 100% in the reported cases.

CONCLUSION

CIUE have a poor perinatal outcome and a high rate of recurrence. There is a relation between clinical expression and histological lesions.

Placental pathology, a survival guide

Placental pathology continues to be an underutilized, undertaught, and inadequately handled surgical subspecialty. The requests for placental pathology are soaring, due partly to demands from obstetricians and to the litigious environment in which they practice, and to improved obstetrical care leading to pregnancies in medically challenging situations. Evaluation of the placenta requires a good understanding of the questions and issues concerning both the fetus/infant and the mother. Information from placental pathology can be critical in early neonatal care and in reproductive planning for the family, and it can provide risk assessment for neurologic outcome of the infant. A comfortable interaction among the obstetric staff, mothers, and pathologists often obviates need for legal intervention in unexpected pregnancy outcomes. Some critical pathologic features that involve maternal and fetal management are illustrated herein. A template for gross examination and a few critical histopathologic diagnostic features with clincopathologic correlation are included.

How valuable is measurement of peripheral blood natural killer cells at the time of abortion?

PROBLEM

Increased peripheral blood natural killer (NK) cells are associated to immune-mediated abortion, but their diagnostic value when measured at the time of miscarriage is unknown.

METHOD OF STUDY

In women with therapeutic (A = 79) or elective (C = 34) pregnancy termination, the NK-cell percentage was measured before and 5 days after curettage. Additionally, immune-mediated lesions (scored 0-3) and CD56(+) and CD16(+) decidual NKs (scored 1-3) were detected on the abortion material.

RESULTS

Aborters differed from controls in histological scores (P = 0.000) and in NK percentage (>12%) only in the measurement 5 days after the operation (P = 0.038). In comparison to histological lesions, NK measurement was found to have sensitivity 70%, specificity 73.68%, positive prognostic value 89.39% and negative prognostic value 43.75%.

CONCLUSION

An Increased NK-cell percentage 5 days after the pregnancy termination could be a marker of immune aetiology of miscarriage, as the probability of an aborter with NK >12% to have an immune-mediated abortion is almost 90%.

Clinical significance of placental examination in perinatal medicine

Complete pathologic evaluation of the placenta provides valuable information for perinatal care for the obstetrician, neonatologist, pediatrician, and family. The histopathology of the placenta can answer specific questions about in utero insults, give insight into management of subsequent pregnancies, and provide an assessment of the newborn risk. Placental pathology has been a key litigious informant in inferring timing of insults. Despite these well known advantages of placental pathologic examination, it remains an under-utilized part of perinatal medicine. This stems from a historically under-taught part of surgical and autopsy pathology resulting in inadequate reporting. This review will focus on the utility of the placental examination for fetal and maternal well-being. This review will be restricted to singleton births.

Pronostic périnatal des grossesses compliquées d’intervillites chroniques placentaires

SUBJECT. Massive Chronic Intervillositis is an infrequent inflammation lesion of the placenta, characterized by lymphohistiocytic intervillous infiltration, associated with fibrinoid deposition. The purpose of this study was to evaluate the perinatal outcome of pregnancies complicated by such lesions.

MATERIAL AND METHODS

We conducted a descriptive retrospective multicentric analysis of a series of pregnancies for which placenta or products of abortion were analyzed between January 1995 and September 2005, at the University Hospital of Bordeaux. After re-examining the histology slides, we performed a semi-quantitative graduation of the cell infiltration and fibrinoid deposition.

RESULTS

Twenty-five women were included (one twin-pregnancy and two histologic recurrences). We found three spontaneous abortions before 22 weeks, four intrauterine fetal deaths and three neonatals deaths. Seven of eight elective inductions pregnancies, were performed for intrauterine growth restriction less than 2.5 percentile. The rate of pregnancy loss was 55% and the perinatal mortality was 29%. 77% of fetuses are small for gestational age. Three mothers were pre-eclamptic. 21% of the fetuses had a congenital malformation. Only 32% of the fetuses were alive one week after birth. Histologically, 25% were associated with lesions of Villitis of Unknown Etiology. 77% of the cell infiltration was grade 3 and seemed to be correlated with severe growth restriction. We describe 3 cases of antenatal diagnosis of Chronic Intervillositis, realised after immunofixation on chorionic villous sampling.

CONCLUSION

Massive Chronic Intervillositis is a recurrent lesion with a poor prognosis complicated by spontaneous abortion, intrauterine growth restriction and perinatal fetal death. Currently, there is no treatment. Chorionic villous sampling in severe growth restriction might be useful in order to obtain at the same time the fetal karyotype and an histological probe of the placenta.

Association des corticoïdes à l’aspirine pour la prévention des récidives de villite ou d’intervillite chroniques d’étiologie indéterminée

We report the cases of two patients who had a favorable outcome with aspirin and corticosteroid therapy during pregnancy for chronic villitis of unknown etiology complicated by labor asphyxia and further intrauterine fetal demise in one gravida 3 patient and for chronic intervillositis of unknown etiology diagnosed after three perinatal deaths in another patient (gravida 4). Chronic villitis of unknown etiology (CVUE) is detected in 7 to 33% of placentas, mainly after intrauterine growth retardation (IUGR), unexplained prematurity, preeclampsia, perinatal asphyxia and intrauterine fetal death (IUFD). The less frequent chronic intervillositis of unknown etiology (CIUE) (0.6 to 0.9/1.000) has been implicated in recurrent severe pregnancy complications, such as spontaneous abortions, IUGR and IUFD. Histopathology and immunohistology are in favor of an immune response against the foreign fetal allograft. The favorable results obtained with corticosteroids and aspirin remain to be confirmed by larger series.

Co-occurrence of massive perivillous fibrin deposition and chronic intervillositis: case report

Chronic intervillositis (CI) and massive perivillous fibrin deposition (MFD), together with its related entity, maternal floor infarction (MFI), are rare and poorly understood placental lesions. Both MFD/MFI and CI are associated with poor fetal outcome and high risk of recurrence. We report a patient who was found to have both MFD and CI in the same placenta, resulting in severe intrauterine fetal growth restriction and intrauterine fetal death at 37 weeks of gestation. Characteristic histological findings included both very extensive perivillous deposition of fibrinoid material and a heavy infiltrate of CD68-positive macrophages/monocytes in the maternal intervillous space. To our knowledge, this is the first time the co-occurrence of MFD and CI is reported in the literature.

Placental pathology and pregnancy outcomes in donor and non-donor oocyte in vitro fertilization pregnancies

OBJECTIVE

Intrinsically poor maternal adaptation to pregnancy and dysregulated processes have been postulated to occur as a consequence of an immune response to the feto-placental unit as "foreign" material. The aim of our study was to compare placental pathology and pregnancy outcomes of in vitro fertilization (IVF) pregnancies conceived by donor oocytes with those conceived by non-donor oocytes.

STUDY DESIGN

We conducted a retrospective, case-control study on 91 placentas from IVF pregnancies (36 from donor oocytes and 55 from non-donor cycles). All placentas were examined by a single pathologist for signs indicative of an immune response, including chronic villitis, chronic deciduitis, increased perivillous fibrin, ischemic change/infarction, decidual vasculopathy, increased syncytial knots, intervillous thrombi, and retroplacental hematomas.

RESULTS

Placentas from donor cycles were significantly more likely to demonstrate certain pathologic findings: chronic villitis (P<0.001), chronic deciduitis (P=0.034), increased perivillous fibrin (P=0.001), ischemic change/ infarction (P=0.001), and intervillous thrombi (P =0.008). There was no statistical significance with respect to decidual vasculopathy, increased syncytial knots, or retroplacental hematomas.

CONCLUSION

Pathologic evidence of an immune-mediated process is much more pronounced in donor oocyte IVF pregnancies compared to non-donor cycles. Clinical implications of these findings have yet to be determined.

Pathophysiology of histological changes in early pregnancy loss

An early pregnancy loss (EPL) or first-trimester miscarriage is the most common complication of human reproduction, with an incidence ranging between 50 and 70% of all conceptions. Two-thirds of EPL cases present with a thinner and fragmented trophoblastic shell, and reduced cytotrophoblast invasion of the tips of the spiral arteries. This leads to incomplete plugging during early pregnancy, and premature onset of the maternal circulation throughout the placenta. The excessive entry of maternal blood into the intervillous space has a direct mechanical effect on the villous tissue, and an indirect oxidative stress effect that contributes to cellular dysfunction and/or damage. Correlation of in vivo and in vitro data suggests that overwhelming oxidative stress of the placental tissues represents a common pathophysiological mechanism for the different etiologies of EPL. Autosomal trisomies are the most frequent karyotypic abnormalities found in EPL, but the comparison of data from different cytogenetic studies is difficult because of the lack of clinical information in many cases on maternal age, gestational age, time of fetal demise and the cytogenetic methodology employed. The majority of authors did find a weak association between villous morphologic features and chromosomal abnormalities, with the exception of partial mole triploidy. The comparison of ultrasound findings and placental histological data indicates that villous changes following fetal demise in utero could explain the overall low predictive value of placental histology alone in identifying an aneuploidy or another non-chromosomal etiology. By contrast, the histological features of complete and partial hydatidiform molar EPL are so distinctive that most cases of molar EPL are correctly diagnosed by histological examination alone. Overall, histopathology when correlated with in vivo ultrasound/Doppler has provided novel clues to the pathophysiology of EPL. Prospective studies are needed to evaluate the impact of these findings on routine histopathologic examination in first-trimester miscarriages.