Inflammatory placental disease

Inflammatory placental diseases constitute a rare group of lesions associated with sometimes severe obstetric complications: pregnancy losses, fetal growth restriction, prematurity and intrauterine fetal death.

They include in particular chronic histiocytic intervillositis, chronic villitis of unknown aetiology and certain forms of massive perivillous fibrin deposition.

Their study lies at the interface of placental pathology, obstetrics and internal medicine. The work in which Arsène Mekinian takes part seeks in particular to clarify their links with autoimmunity, their factors of recurrence and the strategies capable of improving the prognosis of subsequent pregnancies.

Lesions diagnosed on the placenta

The placenta is the organ that connects the mother to the fetus during pregnancy. Maternal blood circulates there in a space, the intervillous space, around small branched structures called villi, which belong to the fetus and through which oxygen and nutrients pass.

Chronic histiocytic intervillositis is characterised by an infiltrate of maternal macrophages, also called histiocytes, in the intervillous space.

Chronic villitis of unknown aetiology corresponds to an inflammation of the stroma of the placental villi in the absence of an identified infectious cause. The 2021 review defines it by lymphohistiocytic infiltrates predominating in the stroma of the villi and distinguishes the low-grade form, which affects fewer than ten contiguous villi, from the high-grade form, patchy or diffuse, the latter affecting more than 30% of the distal villi ⁷.

Massive perivillous fibrin deposition corresponds to a substantial accumulation of fibrin around the villi, liable to impair maternal-fetal exchange. The 2024 systematic review takes as its definition fibrin deposits in the intervillous space occupying at least 25% of the placental volume ⁸.

These lesions may be isolated or associated. Their diagnosis rests mainly on pathological examination of the placenta. The 2021 review notes that chronic villitis is frequently accompanied by other placental lesions, in particular diffuse perivillous fibrin deposits and a chronic intervillositis ⁷. None of these three lesions is visible on ultrasound: they are diagnosed only under the microscope, on the placenta, after the end of the pregnancy.

Two confusions must be set aside. The word histiocytic here describes the type of cell observed in the placenta, the macrophage. It does not denote a histiocytosis, which is a disease of the blood and tissues with no connection whatever to pregnancy. Moreover, an inflammation of the placenta may also have a known infectious cause, and that is then a different situation: it is precisely the absence of an identified cause that defines villitis of unknown aetiology and chronic intervillositis of unknown aetiology. The vocabulary is unsettled from one language to another and from one team to another: chronic histiocytic intervillositis and chronic intervillositis of unknown aetiology, in English chronic histiocytic intervillositis (CHI) and chronic intervillositis of unknown etiology (CIUE), denote the same lesion; villitis of unknown etiology (VUE) is chronic villitis of unknown aetiology; massive perivillous fibrin deposition is written MPFD or MPVFD depending on the authors, and the old name maternal floor infarction covers the most extensive forms.

Placental analysis is therefore an essential step after certain severe or recurrent obstetric complications, because identifying a lesion may alter the assessment and the monitoring of a subsequent pregnancy. That is the conclusion of a prospective observational study published in 2024 in AJOG Global Reports, conducted by the departments of internal medicine and of obstetrics and gynaecology of Jean-Verdier Hospital, of which Arsène Mekinian is last author of nine named authors. Of 4,398 pregnancies delivered in the department, 208 placental analyses, that is 4.7%, were performed and included. The indications were a vascular obstetric complication in 106 cases (51%), an unexplained abnormal fetal heart rate in 59 cases (28.3%), a suspicion of intra-amniotic infection in 12 cases (5.7%), a spontaneous preterm delivery in 19 cases (9.1%), an Apgar score below 7 or an umbilical arterial pH less than or equal to 7 in a term newborn in 7 cases (3.5%) and an intrahepatic cholestasis of pregnancy in 5 cases (2.4%). Histological analysis showed vascular abnormalities in 159 cases (76%), inflammatory lesions in 16 placentas (8%), both vascular and inflammatory lesions in 10 cases (4%), a chorioamnionitis in 38 cases (18%) and no abnormality in 43 cases (21%). The detail of the inflammatory lesions, published in table 2 of the article, gives 8 villitides (4%), 1 isolated chronic intervillositis (0.5%) and 7 associations of villitis and intervillositis (3.3%); perivillous fibrin deposits were noted in 86 placentas (42%) under vascular lesions. A clustering analysis identified three placental profiles, normal, inflammatory (villitis and or chronic intervillositis) and vascular (thrombosis, perivillous fibrin deposits, infarction and villi in chronic hypoxia), the numbers being 43 normal placentas, 6 of inflammatory profile, 149 of vascular profile and 10 combining the two. Women with an inflammatory profile significantly more often had smoking (50% against 9%, p = 0.03), an abnormal uterine Doppler (50% against 5%, p = 0.001), growth restriction (100% against 14%, p = 0.0001) and oligohydramnios (67% against 5%, p = 0.0001) than women with a normal placenta. Oligohydramnios was the only factor associated with the inflammatory profile on univariate analysis, with an odds ratio of 10.3 (confidence interval 2.6 to 41.6, p = 0.004). The authors' conclusion is that histological analysis of the placenta is essential and that its results must be stratified in order better to organise the following pregnancy ¹⁰.

Why study immunity?

The origin of these lesions remains imperfectly understood.

The presence of maternal immune cells in contact with fetal placental structures, their described association with certain autoimmune diseases and their tendency to recur have led to inflammatory, autoimmune or alloimmune mechanisms being proposed.

The starting point of Arsène Mekinian's work on this subject is a case published in 2012 in Rheumatology (Oxford), in the form of a letter: a fetal death occurring in a patient with primary Sjögren's syndrome, with a chronic intervillositis on the placenta. He is its first author, of six named authors, with the obstetrics and pathology team of Jean-Verdier Hospital in Bondy ¹. This case raises the question that governs what follows: in the presence of a chronic intervillositis, should a maternal autoimmune disease be sought systematically?

A first element of an answer came from a retrospective study published in 2015 in Archives of Gynecology and Obstetrics, covering all patients who had had at least one adverse obstetric event associated with a chronic intervillositis of unknown aetiology diagnosed on histological analysis of the placenta between 2004 and 2011 in the same university hospital. Twelve patients and thirty-eight pregnancies were included, the median age being 30 years. An autoimmune disease or autoimmune antibodies were found in 7 of the 12 patients: four primary antiphospholipid syndromes, one Sjögren's syndrome, one pernicious anaemia and one coeliac disease. Comparing the pregnancies of the patients with and without an autoimmune disease, the authors found no difference in the type of obstetric event or in the number of live-born children, despite appropriate treatment. They conclude that the association of an autoimmune disease or of an obstetric antiphospholipid syndrome with an intervillositis could mark a particularly severe form, since conventional treatment did not improve the obstetric outcome, and that the benefit of immunosuppressants in this subgroup needs to be assessed. Arsène Mekinian is second author of nine named authors, behind Aurélie Revaux ².

These hypotheses are biologically plausible, but they are not demonstrated uniformly for all patients: the 2018 review writes that an autoimmune or alloimmune origin is possible, not that it is demonstrated ⁴.

One of the aims is therefore to understand why certain women develop recurrent placental inflammation and to identify the mechanisms that might constitute biomarkers or therapeutic targets.

Lines of research

The work carried out in this field is organised around several questions.

Characterisation of placental lesions. Better defining the histological phenotypes and their associations with obstetric complications. The 2018 review notes that determination of the extent and intensity of the intervillositis is not standardised ⁴, and the 2024 review on massive fibrin deposition notes that all the studies reporting this lesion are retrospective, seventeen studies identified and twelve retained for the final analysis ⁸.

Autoimmunity and inflammation. Investigating the links between placental disease, autoantibodies, antiphospholipid syndrome and maternal autoimmune diseases. An autoimmune disease or autoantibodies were found in 7 of the 12 patients of the 2015 retrospective series ², and an autoimmune disease was present in seven cases out of twenty-four, that is 29%, in the 2015 prospective multicentre study ³.

Risk of recurrence. Identifying the clinical or histological features liable to predict a new complication in a subsequent pregnancy. On univariate analysis of the 2015 prospective study, a history of intrauterine fetal death, a history of intrauterine growth restriction and the presence of an intervillositis on the placenta of the prospective pregnancy were associated with the absence of a live birth ³; the 2018 review writes that there is no reliable predictive marker of recurrence ⁴.

Treatment strategies. Assessing the anti-inflammatory, immunomodulatory and antithrombotic treatments proposed in recurrent and severe forms. The data published by his team are two cases on a TNF alpha antagonist ⁵, four patients on intravenous immunoglobulin ⁶ and one isolated case in 2026 ⁹.

Organisation of the following pregnancy. Determining how analysis of the placenta of a previous pregnancy can contribute to risk stratification and to subsequent obstetric monitoring, the explicit conclusion of the 2024 prevalence study ¹⁰.

Chronic histiocytic intervillositis

Arsène Mekinian's first work on chronic intervillositis concerned its association with autoimmune diseases and the outcome of subsequent pregnancies.

The substantive work is the prospective multicentre study published in 2015 in Autoimmunity, of which he is 1st of 18 named authors and corresponding author, published with the support of the Société nationale française de médecine interne and of the European Forum of APS. All patients with a history of chronic histiocytic intervillositis and an ongoing pregnancy were included prospectively between 2011 and 2013. Twenty-four women, of mean age 34 plus or minus 5 years, were analysed. An autoimmune disease was present in seven cases, that is 29%. Twenty-one of the prospective pregnancies were treated, that is 88%, against 13% of the same women's previous pregnancies. The number of live births was higher than in the previous pregnancies, 16 out of 24 against 24 out of 76 (p = 0.003), which the authors express as a shift from 32% to 67% live births in the treated pregnancies. No difference was observed between the different treatment regimens. On univariate analysis, a history of intrauterine fetal death, a history of intrauterine growth restriction and the presence of an intervillositis on the placenta of the prospective pregnancy were associated with failure, that is with the absence of a live birth. Two figures are given by the authors as the limits of this result: the risk of preterm delivery remained at 30%, and the rate of recurrence of an adverse obstetric event remained at 30% despite the treatment intervention ³.

This study therefore showed the severe and recurrent character of this disease and suggested an improvement in the obstetric outcome in the pregnancies that were managed. The three percentages it publishes, 32%, 67% and 30%, relate to twenty-four women and to a comparison between the pregnancies followed and the same patients' previous pregnancies, with no concurrent control group. The absence of a control group and the small numbers did not make it possible to identify the specific efficacy of a treatment or to compare the different treatment strategies.

In 2018, he signed in La Revue de médecine interne the French review on the subject, published in French under the title Intervillites chroniques histiocytaires : bilan et prise en charge and indexed in MEDLINE in English as Chronic histiocytic intervillositis: Diagnosis and management, 1st of 11 named authors and corresponding author, with co-authors in internal medicine, obstetrics and fetal pathology from Paris, Nantes and Pessac ⁴. The text sets out four findings. Chronic intervillositis is a rare disease, associated with a severe obstetric prognosis and a high rate of recurrence. The adverse obstetric events observed are intrauterine growth restriction, recurrent early miscarriage, intrauterine deaths and prematurity from placental insufficiency. Determination of the extent and intensity of the intervillositis is not standardised, and there is no reliable predictive marker of recurrence. No treatment is validated, but recourse to an immunomodulatory treatment may be justified by a possibly autoimmune or alloimmune origin, in particular in patients with repeated and severe obstetric events and massive histological lesions. This review is the only bibliographic reference cited by the record of the FAI²R network devoted to chronic intervillositis of unknown aetiology.

This work led to further assessment of the relations between placental inflammation, autoimmunity and immunomodulation.

Chronic villitis and massive fibrin deposition

The work was then extended to the other inflammatory or immunological lesions of the placenta.

Chronic villitis of unknown aetiology, particularly in its extensive forms, is associated with an increased risk of obstetric complications and may recur in subsequent pregnancies. On this subject, Arsène Mekinian is first author and corresponding author, of ten named authors, of a review published in 2021 in the Journal of Reproductive Immunology, with co-authors in obstetrics, pathology and internal medicine from Paris and Barcelona. The review describes as characteristic a fetal growth restriction of late onset, after 32 weeks of gestation, earlier detection having first to suggest an infectious origin. High-grade villitis is associated there with growth restriction, prematurity, fetal deaths, recurrent pregnancy loss and lesions of the central nervous system, with a risk of recurrence that the review describes as relatively high and places at between 25 and 50%. The authors conclude that the data on management are extremely scarce and that no recommendation can be formulated from the literature ⁷.

Massive perivillous fibrin deposition likewise constitutes a rare placental disease associated with pregnancy losses, growth restriction, prematurity and fetal death. He is last author of seven named authors and corresponding author of a systematic review published in 2024 in the European Journal of Obstetrics and Gynecology and Reproductive Biology, of which Meryam Cheloufi is first author. Seventeen studies were identified, of which twelve were retained for the final analysis, and all the studies reporting this lesion are retrospective. The reported prevalence is 1.1% in pregnancies delivered after 22 weeks of gestation, and rises to 2.7% in cases of recurrent early miscarriage. The reported risk of fetal death ranges mainly from 15 to 80% depending on the study. Preterm delivery is spontaneous in 50 to 70% of cases and induced by severe growth restriction in 30 to 50% of cases depending on the study. The authors write that no diagnostic biomarker is available and that the mechanisms remain little studied ⁸.

An isolated case was added in 2026, in the Journal of Reproductive Immunology, of which he is last author of six named authors and corresponding author: a woman of 41 years, with systemic autoimmune diseases and a history of ten pregnancy losses, with perivillous fibrin deposits confirmed histologically on the two available placentas and without chronic histiocytic intervillositis on the material reviewed, carried a pregnancy to term and delivered by caesarean section a live child in good health, on an immunomodulatory protocol combining intravenous immunoglobulin, corticosteroids, hydroxychloroquine and antithrombotic treatment. The authors write themselves, in the abstract, that no causal attribution to one or other of these drugs can be established, given the single nature of the case, the incomplete histological documentation of the previous losses and the simultaneous use of several treatments ⁹.

The reviews conducted in these fields underline above all the heterogeneity of definitions, the scarcity of prospective studies and the absence of a biomarker currently allowing individual prediction of recurrence.

What place for immunomodulatory treatments?

Several strategies have been reported in recurrent forms: corticosteroids, hydroxychloroquine, intravenous immunoglobulin, TNF antagonists, aspirin and heparins, alone or in combination.

The available data come mainly from observational cohorts, small series and case reports. They constitute therapeutic signals and research hypotheses, but do not currently make it possible to define a standardised treatment strategy.

Arsène Mekinian signs two short series, both presented by their authors as observations and not as proof. In 2019, in the European Journal of Obstetrics and Gynecology and Reproductive Biology, he reports two cases illustrating the use of a TNF alpha antagonist, adalimumab, in situations of refractory recurrent chronic intervillositis and unexplained miscarriage, having recalled that he had previously described the benefit of the combination of hydroxychloroquine and prednisone in forms with repeated obstetric events and intrauterine deaths. He is 1st of 8 named authors and corresponding author ⁵. In 2024, in the American Journal of Reproductive Immunology, the team reports four patients with recurrent chronic histiocytic intervillositis after failure of corticosteroids and hydroxychloroquine. All had at least four pregnancy losses, with histological confirmation of the intervillositis for at least one of them, and a negative aetiological and immunological work-up. In three patients, intravenous immunoglobulin was started as soon as beta-hCG became positive, at a dose of 1 g/kg every two weeks until delivery; in the fourth, already on combined treatment since the beginning of the pregnancy, it was introduced at 20 weeks of amenorrhoea because of severe growth restriction. Two patients delivered a live child at 36 weeks and one at 39 weeks; the fourth, who had first-trimester hypertension and severe placental lesions, lost her pregnancy at 15 weeks. The authors themselves describe this result as a potential benefit and write that larger studies are needed to confirm it. Arsène Mekinian is the 10th and last named author of this article; the MEDLINE record carries no correspondence address ⁶.

He is also last author, of five named authors, of a review in French published in 2025 in La Revue de médecine interne, of which Amandine Dernoncourt is first author and corresponding author, devoted to hydroxychloroquine in recurrent immune-mediated obstetric disease outside systemic lupus. This review places chronic intervillositis of unknown aetiology among the empirical indications for hydroxychloroquine, justified by the hypothesis of alloimmune or autoimmune mechanisms, and writes that a few clinical studies of low level of evidence suggest a benefit of hydroxychloroquine in this indication, but that further data are needed. The same text writes that current data do not support the use of hydroxychloroquine in unexplained recurrent miscarriage ¹¹.

No randomised controlled trial has, to date, established the efficacy of a specific immunomodulation in these lesions. The systematic review and meta-analysis by Moar et al., published in 2022 in Frontiers in Endocrinology (PMID 35937841, DOI 10.3389/fendo.2022.945543), writes explicitly that no randomised trial was identified: in a population of 659 pregnancies, the treatments used were aspirin, prednisone, prednisolone, low molecular weight heparin, hydroxychloroquine and adalimumab, and the quantitative synthesis of 38 pregnancies gives a non-significant improvement in live births on targeted treatment, odds ratio 1.79, 95% confidence interval 0.33 to 9.61, p = 0.50. This reference is not his and is cited here only to situate his work ¹².

Multidisciplinary care

Care rests on the combination of several forms of expertise, and none is sufficient on its own.

The pathologist identifies and characterises the placental lesion and describes its extent.

The obstetrician assesses the risk of recurrence, organises maternal and fetal monitoring, decides on the term and adapts the management of the pregnancy.

The internist looks for an associated autoimmune or autoinflammatory disease, in particular an antiphospholipid syndrome, and takes part in the discussion of treatment strategies in complex forms.

This work brings together in particular the department of internal medicine and clinical immunology of Saint-Antoine Hospital, the obstetrics and pathology teams of Armand-Trousseau Hospital and the obstetrics and gynaecology and reproductive medicine teams of Tenon Hospital, within AP-HP and Sorbonne Université.

The affiliations that appear on the publications cited above outline this organisation: department of internal medicine of Saint-Antoine Hospital, AP-HP, Sorbonne Université, attached to the medical and university department devoted to inflammation, immunopathology and biotherapies, designated DHU i2B until about 2019, then DMU 3iD and DMU i3 in the affiliations of his publications; department of pathological anatomy and cytology and department of obstetrics of Armand-Trousseau Hospital; department of obstetrics and gynaecology and reproductive medicine of Tenon Hospital. The oldest work, that of 2012 and 2015, is signed from the department of internal medicine and the department of obstetrics of Jean-Verdier Hospital in Bondy, and the 2024 prevalence study also comes from that site. The affiliation carried on the 2025 review mentions the reference centre for autoinflammatory diseases and inflammatory amyloidosis of Saint-Antoine.

In France, these lesions come under the FAI²R rare disease health network, the network for rare autoimmune and autoinflammatory diseases, whose record devoted to chronic intervillositis of unknown aetiology cites the 2018 review as its only bibliographic reference. Complex situations may be discussed in a multidisciplinary team meeting, in particular within the national Infertility meeting of the FAI²R network, of which Arsène Mekinian states that he provides the coordination; this discussion takes the form of a multidisciplinary team meeting, and treatments given intravenously, in particular immunoglobulin, come under the day hospital. Pathological examination of the placenta after a pregnancy loss or a severe obstetric complication is the act on which everything that follows depends: without it, these diagnoses are not made, and the conclusion of the 2024 prevalence study is precisely that this examination must be carried out and its results stratified in order to organise the following pregnancy ¹⁰.

What remains to be demonstrated

Three main questions remain open.

The first concerns mechanisms: the respective contributions of autoimmunity, alloimmunity, inflammation and placental vascular mechanisms remain to be clarified. The 2018 review writes that an autoimmune or alloimmune origin is possible, not that it is demonstrated ⁴; the 2024 review on massive fibrin deposition writes that the mechanisms are little studied and that no diagnostic biomarker exists ⁸; the 2021 review on chronic villitis writes that the data on management are extremely scarce and that no recommendation can be drawn from the literature ⁷. The diagnosis remains retrospective, made on the placenta after the end of the pregnancy, and no examination today makes it possible to announce the lesion during the pregnancy in progress.

The second concerns the prediction of recurrence: no clinical, biological or histological biomarker currently makes it possible to determine with precision the individual risk in a subsequent pregnancy. The recurrence figures do not in fact agree from one source to another, and this discrepancy must be stated rather than averaged. His 2015 prospective study measures a rate of recurrence of an adverse obstetric event of 30% despite treatment, in twenty-four women followed between 2011 and 2013 ³. His 2021 review cites for high-grade villitis a risk of recurrence of 25 to 50%, which is a range taken from the literature and not a measurement made by its authors ⁷. The discussion of his 2024 prevalence study puts forward, for intervillositis and villitis, a range of 30 to 60% ¹⁰. These three values relate neither to the same lesions, nor to the same numbers, nor to the same definitions of recurrence, histological or clinical. None of them makes it possible to tell a given patient what her personal risk is, and his own 2018 review writes that there is no reliable predictive marker of recurrence ⁴.

The third is therapeutic: the available data do not make it possible to determine which immunomodulation to use, in which patients, in which combination or for how long. His own work has limits that its authors state. The 2015 prospective study includes no control group treated in parallel: the improvement from 32% to 67% live births compares the pregnancies followed with the same women's previous pregnancies, a comparison in which regression to the mean, the selection of the patients included and the general improvement in care cannot be separated from the effect of treatment, and the study itself finds no difference between the treatment regimens used ³. The 2015 study on associated autoimmune diseases is retrospective and concerns twelve patients ². The intravenous immunoglobulin series concerns four patients, without a control group, with one failure out of four ⁶; the TNF alpha antagonist series concerns two cases ⁵; the 2026 case on fibrin deposition concerns a single patient and its authors write that causal attribution is impossible ⁹. The 2024 prevalence study is single-centre, includes no normal pregnancies as a comparison group, which its authors flag as its main limitation, and the six placentas of inflammatory profile in its clustering analysis are a number on which no percentage should be commented upon without caution ¹⁰. That same publication moreover carries two different inclusion periods depending on the passage, from December 2015 to October 2017 in the abstract and from December 2015 to May 2016 in the methods and results, this second period being the only one compatible with the six-month protocol announced.

No randomised controlled trial has assessed a treatment of these lesions, and the 2022 meta-analysis by Moar et al. says so explicitly ¹². The consensus of the Amsterdam Placental Workshop Group on placental pathology, Khong et al., Archives of Pathology and Laboratory Medicine 2016 (PMID 27223167, DOI 10.5858/arpa.2015-0225-CC), which sets the terminology and the criteria for sampling and describing placental lesions, including villitis of unknown etiology, is likewise not his ¹³. These two references are cited here to situate his work, and he is a signatory of neither.

Finally, what this work does not say must also be said. No registered interventional study specifically concerning chronic intervillositis, chronic villitis or massive fibrin deposition has been identified. None of the published series makes it possible to choose between the available immunomodulatory treatments, or to say which should be combined, or for how long. None makes it possible to say which patients derive a benefit from these treatments and which derive none. The total number of patients documented across all his publications on these lesions is counted in tens, which is the dominant fact of this file and the reason why each result cited above must be read as an observation and not as proof.

The research priorities are therefore to standardise the pathological characterisation, better define the clinical and immunological phenotypes, develop predictive biomarkers and assess treatment strategies in prospective controlled studies.

References

Published work he has taken part in, on this subject.

• Fetal death in primary SS associated with chronic intervillositis — Rheumatology (Oxford), 2012 1st of 6 named authors. Letter, no abstract; paywalled at the publisher.
• Antiphospholipid syndrome and other autoimmune diseases associated with chronic intervillositis — Archives of Gynecology and Obstetrics, 2015 2nd of 9 named authors. Retrospective study, 12 patients; paywalled at the publisher.cited 21 times
• Chronic histiocytic intervillositis: outcome, associated diseases and treatment in a multicenter prospective study — Autoimmunity, 2015 1st of 18 named authors, corresponding author; the consortium "SNFMI and the European Forum of APS" appears as a collective signature and is not counted in the position. Prospective multicentre study, 24 women; paywalled at the publisher.cited 60 times
• Intervillites chroniques histiocytaires : bilan et prise en charge (article published in French; MEDLINE title in English: Chronic histiocytic intervillositis: Diagnosis and management) — La Revue de médecine interne, 2018 1st of 11 named authors, corresponding author. The French review of reference on the subject, and the only bibliographic reference cited by the FAI²R record; paywalled at the publisher.
• Antagonists of TNFα for recurrent miscarriages: 2 Illustrative cases — European Journal of Obstetrics & Gynecology and Reproductive Biology, 2019 1st of 8 named authors, corresponding author. Two cases; paywalled at the publisher.
• Intravenous Immunoglobulins for Recurrent Chronic Histiocytic Intervillositis: A Series of Case Studies — American Journal of Reproductive Immunology, 2024 10th of 10 named authors, last author; no correspondence address in the MEDLINE record. Four patients; paywalled at the publisher.
• Chronic Villitis of unknown etiology (VUE): Obstetrical features, outcome and treatment — Journal of Reproductive Immunology, 2021 1st of 10 named authors, corresponding author. Review of the literature; paywalled at the publisher.cited 25 times
• Massive perivillous fibrin deposition: Diagnosis, obstetrical features, and treatment — European Journal of Obstetrics & Gynecology and Reproductive Biology, 2024 7th of 7 named authors, last author and corresponding author. Systematic review, 17 studies identified and 12 retained; paywalled at the publisher.
• Successful live birth following immunomodulatory therapy in a patient with multiple recurrent pregnancy loss and massive perivillous fibrinoid deposition — Journal of Reproductive Immunology, 2026 6th of 6 named authors, last author and corresponding author. Single case; paywalled at the publisher.
• Prevalence and association of placental lesions with obstetrical features and outcome: data from French prospective study — AJOG Global Reports, 2024 9th of 9 named authors, last author; the MEDLINE record carries no correspondence address, the PMC page designates him as corresponding author. Open access free full text
• Utilisation de l'hydroxychloroquine dans les pathologies obstétricales récurrentes à médiation immune (en dehors du lupus systémique) : fondements et preuves scientifiques (article published in French) — La Revue de médecine interne, 2025 5th of 5 named authors, last author; corresponding author Amandine Dernoncourt. Paywalled at the publisher.
• Chronic histiocytic intervillositis (CHI): current treatments and perinatal outcomes, a systematic review and a meta-analysis — Frontiers in Endocrinology (Lausanne), 2022 Moar L, Simela C, Nanda S, Marnerides A, Al-Adnani M, Nelson-Piercy C, Nicolaides KH, Shangaris P, 8 named authors, Arsène Mekinian is not a signatory. Open access free full text
• Sampling and Definitions of Placental Lesions: Amsterdam Placental Workshop Group Consensus Statement — Archives of Pathology & Laboratory Medicine, 2016 Khong TY et al., 29 named authors, Arsène Mekinian is not a signatory. Sets the terminology and the sampling and description criteria for placental lesions, including villitis of unknown etiology free full text at the publisher

General information only. This page does not replace individual medical advice. Updated: 10 September 2026.