Differences in Placental Pathologic Features by Trimester of Infection with SARS-CoV-2.

Area of Science:

• Obstetrics and Gynecology
• Infectious Diseases
• Pathology

Background:

• SARS-CoV-2 infection during pregnancy presents unique challenges.
• Understanding placental pathology associated with COVID-19 is crucial for maternal and fetal health.
• Differences in placental findings based on the trimester of SARS-CoV-2 infection require investigation.

Purpose of the Study:

• To describe placental findings in pregnancies with SARS-CoV-2 infection.
• To investigate differences in placental pathology based on the trimester of infection.

Main Methods:

• Analysis of placental pathology in 314 pregnant patients with SARS-CoV-2 infection.
• Categorization of placental pathology: acute inflammation (AI), chronic inflammation (CI), maternal vascular malperfusion (MVM), and fetal vascular malperfusion (FVM).
• RT-PCR for SARS-CoV-2 performed on placental tissue in 75% of cases.

Main Results:

• Prevalence of AI, CI, FVM, and MVM did not differ by trimester.
• High-grade inflammatory and/or vascular pathology were more prevalent with earlier infection (1st trimester: 67.5%, 2nd: 55.2%, 3rd: 39.6%).
• Third-trimester infection close to delivery was associated with higher FVM prevalence.

Conclusions:

• Earlier SARS-CoV-2 infection in pregnancy is associated with increased high-grade placental inflammatory and vascular pathology.
• The timing of infection influences the type and severity of placental lesions.
• Further research is needed to understand the long-term implications of these findings.