SARS-CoV-2 variant-related abnormalities detected by prenatal MRI: a prospective case-control study

Area of Science:

• Obstetrics and Gynecology
• Radiology
• Infectious Diseases

Background:

• Complications for fetuses following SARS-CoV-2 infection during pregnancy are known.
• Previous studies primarily focused on placental histopathology.
• Research on SARS-CoV-2 variants' effects on pregnancy is limited.

Purpose of the Study:

• To investigate the effects of SARS-CoV-2 variants on placental and fetal structures.
• To utilize prenatal MRI for assessing these effects.
• To compare the impact of pre-Omicron and Omicron variants.

Main Methods:

• Prospective case-control study involving 38 pregnant women with SARS-CoV-2 infection and 38 matched controls.
• Prenatal MRI was used to examine placental morphology (shape, thickness, lobulation, vascular lesions) and fetal development.
• Placental pathology and vaccination status were analyzed where available.

Main Results:

• Both pre-Omicron and Omicron variants caused globular placentas.
• Placentas from the pre-Omicron group showed significant thickening, lobulation, and hemorrhages.
• Fetal growth restriction was observed in 25% of cases infected with pre-Omicron variants.

Conclusions:

• SARS-CoV-2 infection can cause placental lesions visualized by prenatal MRI.
• Pre-Omicron variants appear to induce more severe placental damage compared to Omicron sub-lineages.
• Prenatal MRI is a valuable tool for assessing SARS-CoV-2 related pregnancy complications.