An exploratory evaluation of the clinical characteristics and treatment outcomes of patients diagnosed with chronic histiocytic intervillositis.

INTRODUCTION Chronic histiocytic intervillositis (CHI) is a rare placental lesion associated with an aberrant, noninfectious activation of the maternal immune response. Macrophages then accumulate within the intervillous space of the placenta, with associated adverse outcomes. This study aimed to describe clinical characteristics and treatment outcomes in subsequent pregnancies of patients diagnosed with CHI.

Methods

This retrospective exploratory analysis utilized data abstracted from electronic medical records at a single institution. Patients with at least one pregnancy diagnosed with CHI confirmed by placental histopathology reports were included. Patients with intervillositis of infectious origin were excluded.

Results

Nineteen patients were included, with the majority being white (89.5%, n = 17), with a median age of 27 years at the time of delivery. Ten (52.6%) patients had autoimmune disease, and 11 (57.9%) had hypertension. Among the 19 patients, there were 61 pregnancies. Nineteen (31.1%) were pregnancies in which CHI was initially diagnosed (index pregnancy), and 47.5% (29/61) of pregnancies occurred after the index pregnancy. Of these post-index pregnancies, 70% (7/10) were diagnosed with CHI based on available placental pathology. Twenty (38.2%) pregnancies reported complications. Pregnancy loss occurred in 55% (11/20) of index pregnancies, and 40% (10/25) of post-index pregnancies. Nineteen (70%) post-index pregnancies received immunomodulatory treatment. Of pregnancies where treatment was not initiated, 61.1% (22/36) resulted in loss, while in pregnancies that received treatment, 21.1% (4/19) resulted in loss (p = 0.004).

Discussion

Patients who initiated immunomodulatory treatment in post-index pregnancies had an associated decrease in placental fibrin deposition and were associated with a higher rate of living children.