An Update on COVID-19-Associated Placental Pathologies

Area of Science:

• Obstetrics and Gynecology
• Infectious Diseases
• Pathology

Background:

• Pregnancy with COVID-19 is linked to higher rates of preterm birth and stillbirth.
• The existence of a specific COVID-19-related placental pathology pattern remains debated.
• Previous studies suggested potential placental changes in COVID-19 pregnancies.

Purpose of the Study:

• To update and analyze the existing literature on placental histopathological changes in pregnancies affected by COVID-19.
• To determine if COVID-19 infection is associated with a unique pattern of placental pathology.
• To assess the frequency of specific placental pathologies in COVID-19 versus non-COVID-19 pregnancies.

Main Methods:

• Systematic literature review and meta-analysis of published reports.
• Evaluation of histopathological findings in placentas from 3677 pregnancies (38 reports).
• Comparison of placental pathology frequencies between COVID-19 and non-COVID-19 pregnancies.

Main Results:

• Frequent pathologies included maternal vascular malperfusion (32%), fetal vascular malperfusion (19%), and inflammation (20-22%).
• Similar histologic patterns and frequencies of manifestation were observed in non-COVID-19 pregnancies.
• COVID-19 placentitis was found in only 1-2% of cases, indicating rarity.

Conclusions:

• COVID-19 infection during pregnancy does not appear to increase the rate of specific placental pathologies.
• The observed placental findings in COVID-19 pregnancies are largely non-specific and similar to those in non-COVID-19 cases.
• COVID-19 placentitis is an infrequent condition, suggesting limited direct placental impact.