Effect of COVID-19 infection in the third trimester of pregnancy on innate immunity parameters, association with obstetric and perinatal outcomes

Abstract

Aim. To analyze and compare parameters of innate immunity with obstetric and perinatal outcomes in patients with COVID-19 in the third trimester of pregnancy. Materials and methods. The study included 2 groups: the main group encompassed patients with mild (subgroup 1, n = 31) and moderate (subgroup 2, n = 40) COVID-19 during the third trimester of pregnancy; the control group included women who did not have COVID-19 during pregnancy (n = 22). By the enzyme-linked immunosorbent assay (ELISA), we determined the level of anti-SARS-CoV-2 immunoglobulin (Ig)M and IgG, tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6), and interferon gamma (IFNγ) in the blood plasma. Complete blood count was performed on the automated hematology analyzer. Expression of CD-14 and HLA-DR antigens in monocytes was analyzed on the flow cytometer. SARS-CoV-2 RNA in placenta samples was detected by the reverse transcription polymerase chain reaction (RT-PCR). Results. A moderate course of COVID-19 in the third trimester of pregnancy was associated with lower levels of anti-SARS-CoV-2 IgG and IFNγ in the maternal blood and umbilical cord blood, as well as by lower expression of CD-14 and HLA-DR by monocytes compared to mild COVID-19. A mild course of the disease was characterized by an increase in the number of monocytes in the maternal blood. No differences in leukocyte and lymphocyte counts were noted. There were also no differences in birth weight and one-minute Apgar score. At 5 minutes, the Apgar scores for moderate COVID-19 were lower than those for mild infection. The moderate course of COVID-19 increased the risk of preterm birth, neonatal cerebral ischemia, intraventricular hemorrhage, and respiratory distress syndrome. No risk of intrauterine SARS-CoV-2 infection was detected. Conclusion. The severity of COVID-19 in the third trimester of pregnancy is associated with dysregulation of the innate immunity, which determines the nature of obstetric and perinatal complications.