Influence of COVID-19 infection on placental function

Pregnant women are more susceptible to infectious diseases because of their natural immunosuppression. SARS-CoV-2 seems to be a potential risk for the condition of women and the fetus. Unfortunately, knowledge of the influence of coronavirus disease 19 (COVID-19) on pregnant women and their children is still very limited, and further investigation and analysis are needed. The aim of the study was to conduct a meta-analysis of research about the impact of COVID-19 on the placenta.

Articles published between 2020 and 2021 and contained in the PubMed and Elsevier databases were analyzed.

The SARS-CoV-2 infection also led to pregnancy complications in the patients. The most common pregnancy complications include caesarean delivery (80%), preterm delivery (26%), fetal distress (8%), premature rupture of the membranes (9%) and stillbirth (2%). Among the observed patients, neonatal complications occurred, such as premature delivery (25%), respiratory distress syndrome (8%), pneumonia (8%) and deaths of 4 newborns SARS-CoV-2 was found mainly in syncytiotrophoblast cells at the maternal-fetal border of the placenta. Histological examination of the placenta revealed dense macrophage infiltration. Abnormal perfusion of fetal blood vessels or fetal vascular thrombosis was observed. Elevated levels of SARS-CoV-2 IgG or IgM antibodies in the umbilical cord blood were observed in nine newborns, reported as evidence of vertical infection.

The features of placental damage in women with COVID-19 are clearly different from the control group. Further research is needed to better understand how SARS-CoV-2 infection affects the placenta.