Inflammation and Immune Reactions in the Fetus as a Response to COVID-19 in the Mother.

Background: Contracting COVID-19 during pregnancy can harm both the mother and the unborn child. Pregnant women are highly likely to develop respiratory viral infection complications with critical conditions caused by physiological changes in the immune and cardiopulmonary systems. Asymptomatic COVID-19 in pregnant women may be accompanied by fetal inflammatory response syndrome, which has adverse consequences for the newborn's life and health. Purpose: To conduct an inflammatory response assessment of the fetus due to the effects of COVID-19 on the mother during pregnancy by determining pro-inflammatory cytokines, cell markers, T regulatory cells, T cell response, evaluation of cardiac function, and thymus size. Materials and methods: A prospective study included pregnant women (n = 92). The main group consisted of 62 pregnant women with COVID-19 infection: subgroup 1-SARS-CoV-2 PCR-positive pregnant women 4-6 weeks before delivery (n = 30); subgroup 2-SARS-CoV-2 PCR-positive earlier during pregnancy (n = 32). The control group consisted of 30 healthy pregnant women. In all pregnant women, the levels of circulating cytokines and chemokines (IL-1α, IL-6, IL-8, IL-10, GM-CSF, TNF-α, IFN-γ, MIP-1ß, and CXCL-10) were determined in the peripheral blood and after delivery in the umbilical cord blood, and an analysis was performed of the cell markers on dendritic cells, quantitative and functional characteristics of T regulatory cells, and specific T cell responses. The levels of thyroxine and thyroid-stimulating hormone were determined in the newborns of the studied groups, and ultrasound examinations of the thymus and echocardiography of the heart were also performed. Results: The cord blood dendritic cells of newborns born to mothers who suffered from COVID-19 4-6 weeks before delivery (subgroup 1) showed a significant increase in CD80 and CD86 expression compared to the control group (p = 0.023). In the umbilical cord blood samples of children whose mothers tested positive for COVID-19 4-6 weeks before delivery (subgroup 1), the CD4+CCR7+ T cells increased with a concomitant decrease in the proportion of naive CD4+ T cells compared with the control group (p = 0.016). Significantly higher levels of pro-inflammatory cytokines and chemokines were detected in the newborns of subgroup 1 compared to the control group. In the newborns of subgroup 1, the functional activity of T regulatory cells was suppressed, compared with the newborns of the control group (p < 0.001). In all pregnant women with a severe coronavirus infection, a weak T cell response was detected in them as well as in their newborns. In newborns whose mothers suffered a coronavirus infection, a decrease in thymus size, transient hypothyroxinemia, and changes in functional parameters according to echocardiography were revealed compared with the newborns of the control group. Conclusions: Fetal inflammatory response syndrome can occur in infants whose mothers suffered from a COVID-19 infection during pregnancy and is characterized by the activation of the fetal immune system and increased production of pro-inflammatory cytokines. The disease severity in a pregnant woman does not correlate with SIRS severity in the neonatal period. It can vary from minimal laboratory parameter changes to the development of complications in the organs and systems of the fetus and newborn.

Use of the low-molecular-weight heparin nadroparin during pregnancy. A review.

Antithrombotic therapy is often used during pregnancy for the treatment and prevention of venous thromboembolism, the prevention of systemic embolism in patients with heart valve prostheses and the prevention of foetal loss in patients with antiphospholipid syndrome. Low-molecular-weight heparins (LMWHs), including nadroparin, have largely replaced unfractionated heparin as the anticoagulant of choice. The use of the LMWH nadroparin in pregnant women at an increased risk of thromboembolism or foetal loss is discussed in this review. Deep vein thrombosis can be effectively treated or prevented with nadroparin without any serious adverse events. Nadroparin 0.1 ml/10 kg s.c. once daily prevents thromboembolic complications in pregnant women with heart valve prostheses. Nadroparin is also effective in preventing foetal loss, through contributing to normal placental development and in decreasing the risk of premature delivery in pregnant women with antiphospholipid syndrome or women with herpes and antiphospholipid syndrome. These results demonstrate nadroparin is effective, easy to administer and associated with a low incidence of foetal and maternal complications. The use of nadroparin at a prophylactic dose of 0.3 ml (2850 IU AXa, 95 IU/kg) (for high-risk patients, 0.3-0.6 ml) s.c. once daily, and a therapeutic dose of 0.1 ml/10 kg (95 IU/kg) s.c. twice daily, is in line with the latest international guidelines of the American College of Chest Physicans.