MR imaging findings of massive perivillous fibrin deposition of the placenta: A case report

Massive perivillous fibrin deposition (MPFD) of the placenta is characterized by the obliteration of the villous trophoblast with extensive deposition of fibrinoid material in the intervillous space. Here, we describe the MRI findings of a case of MPFD. The placenta demonstrates linear and geographical hypointensity on T2-weighted imaging, which is suggested to mainly reflect fibrin deposition. This finding should be noted, particularly in patients with miscarriage in their past history.

Recurrent massive perivillous fibrin deposition treated with aspirin and enoxaparin: A case report

Massive perivillous fibrin deposition (MPVFD) is a potentially devastating complication of pregnancy that occurs in 0.03-0.5% of deliveries and is associated with severe fetal growth restriction, stillbirth, and neurologic injury due to uteroplacental insufficiency. The management of patients with recurrent pregnancy loss secondary to MPVFD has not been widely studied. We describe the case of a healthy 19-year-old with a history of two prior intrauterine fetal demises at 35w6d and 36w6d secondary to MPVFD of the placenta who subsequently delivered a healthy infant at 33w6d after she had been treated in the prenatal period with aspirin and prophylactic enoxaparin. Antenatal treatment with daily aspirin and prophylactic enoxaparin as well as close antenatal follow-up may be an option for patients with recurrent pregnancy loss due to MPVFD.

Predictive factors for severe placental damage in pregnant women with SARS-CoV-2 infection

INTRODUCTION

SARS-Cov-2 infection during pregnancy can lead to severe placental lesions characterized by massive perivillous fibrin deposition, histiocytic intervillositis and trophoblast necrosis. Diffuse placental damage of this kind is rare, but can sometimes lead to obstetric complications, such as intrauterine fetal death (IUFD). The objectives of this study were to identify possible predictors of severe placental lesions.

METHODS

We retrospectively studied 96 placentas from SARS-Cov-2 positive pregnant women who gave birth between March 2020 and March 2022. Cases with and without severe placental lesions were compared in terms of clinical and laboratory findings.

RESULTS

Twelve of the 96 patients had severe placental lesions. There was no significant association with diabetes, obesity or severe clinical maternal disease. In contrast, presence of severe placental lesions was significantly associated with neonatal intensive care, cesarean section, prematurity, IUFD, intrauterine growth restriction (IUGR), gestational age, maternal hypofibrinogenemia and thrombocytopenia. No cases of severe placental lesions were observed in vaccinated patients or in those with the Omicron variant.

DISCUSSION

In these patients, severe placental lesions due to SARS-Cov-2 were significantly associated with the presence of coagulation abnormalities (hypofibrinogenemia and thrombocytopenia), IUGR and gestational age. These results support laboratory and ultrasound monitoring of these parameters in pregnant women with SARS-Cov-2 infection, especially during the second trimester, to predict potential negative fetal outcomes.

SARS-COV2 placentitis and pregnancy outcome: A multicentre experience during the Alpha and early Delta waves of coronavirus pandemic in England

BACKGROUND

Pregnant women with SARS-CoV-2 infection experience higher rates of stillbirth and preterm birth. A unique pattern of chronic histiocytic intervillositis (CHI) and/or massive perivillous fibrin deposition (MPFD) has emerged, coined as SARS-CoV-2 placentitis.

METHODS

The aim of this study was to describe a cohort of placentas diagnosed with SARS-CoV-2 placentitis during October 2020-March 2021. Cases with a histological diagnosis of SARS-CoV-2 placentitis and confirmatory immunohistochemistry were reported. Maternal demographic data, pregnancy outcomes and placental findings were collected.

FINDINGS

59 mothers delivered 61 infants with SARS-CoV-2 placentitis. The gestational age ranged from 19 to 41 weeks with most cases (78.6%) being third trimester. 30 infants (49.1%) were stillborn or late miscarriages. Obese mothers had higher rates of pregnancy loss when compared with those with a BMI <30 [67% (10/15) versus 41% (14/34)]. 47/59 (79^.7%) mothers had a positive SARS-CoV-2 PCR test either at the time of labour or in the months before, of which 12 (25^.5%) were reported to be asymptomatic. Ten reported only CHI, two cases showed MPFD only and in 48 placentas both CHI and MPFD was described.

INTERPRETATION

SARS-CoV2 placentitis is a distinct entity associated with increased risk of pregnancy loss, particularly in the third trimester. Women can be completely asymptomatic and still experience severe placentitis. Unlike 'classical' MPFD, placentas with SARS-CoV-2 are generally normal in size with adequate fetoplacental weight ratios. Further work should establish the significance of the timing of maternal SARS-CoV-2 infection and placentitis, the significance of SARS-CoV2 variants, and rates of vertical transmission associated with this pattern of placental inflammation.

FUNDING

There was not funding associated with this study.

Clinicopathological characteristics of miscarriages featuring placental massive perivillous fibrin deposition

INTRODUCTION

Massive perivillous fibrin deposition (MPFD) is frequently associated with detrimental pregnancy outcomes, and extensive perivillous fibrin deposition results in severe placental dysfunction and loss of maternofetal interface. Unfortunately, the fundamental pathogenesis of MPFD remains unknown, and systematic analyses of MPFD in miscarriage is lacking. We analyzed the frequency and clinicopathological characteristics of MPFD in first trimester miscarriages.

METHODS

We analyzed a consecutive series of miscarriages (n = 582) gathered between March 2012 and June 2016. MPFD was classified as fibrin-type (f-MPFD) and matrix-type (m-MPFD) by immunostaining for fibrin and collagen type IV. The control group consisted of miscarriage cases (MC, n = 18) that were matched to f-MPFD with normal chromosome (f-MPFD-nc) for number of previous miscarriages and placental chromosomal status.

RESULTS

MPFD was identified in 2.7% of miscarriages. f-MPFD was associated with recurrent abortions. Compared with miscarriages without fibrin deposition, MPFD cases had higher proportion of those with normal placental chromosome (69.2% vs. 27.4%, P < 0.005) and higher frequency of villous syncytiotrophoblast C4d deposition (73.3% vs. 33.9%, P < 0.005). All C4d(+) f-MPFD patients had more than three recurrent miscarriages, whereas C4d(-) f-MPFD patients had no history of recurrent miscarriage (P < 0.05). Patients with f-MPFD-nc had significantly higher HLA PRA immunopositivity rate than did MC patients (P = 0.005).

DISCUSSION

MPFD was more common in miscarriages than in preterm and term pregnancies. Placental massive fibrin-type fibrinoid deposition and villous C4d immunoreactivity were associated with recurrent miscarriage.