Assessment of the effectiveness of COVID-19 preventive measures in pregnant women
Authors:   Chita State Medical Academy, Chita, Russian Federation, Belokrinitskaya T.E. , Frolova N.I. ,   Chita State Medical Academy, Chita, Russian Federation, Kolmakova K.A. ,   Chita State Medical Academy, Chita, Russian Federation, Shametova E.A. ,   City Clinical Hospital No 1, Chita, Russian Federation, Veselkova I.Yu. ,   Central District Hospital, Chita, Russian Federation, Osmonova Sh.R. ,   Chita State Medical Academy, Chita, Russian Federation
Published: December 2022

Objective. To assess the effectiveness of different preventive measures for novel coronavirus infection in pregnant women. Patients and Methods. This study included 125 pregnant women hospitalized with moderate to severe laboratory-confirmed SARS-CoV-2 infection between September and November 2021 (the fourth pandemic wave), and 175 pregnant women who were not infected with COVID-19 during the same period. All women in these two groups were comparable for gestational age (II–III trimesters, 24–39 weeks), age (20–40 years), social status, parity, body mass index, and had no known COVID-19 risk factors. Results. Our findings revealed that vaccination 3-5 months before pregnancy (OR = 4.12; 95% CI 1.28–13.27; χ2 = 0.022), inconsistent use and/or non-timely replacement of face masks (OR = 5.71; 95% CI 2.83–11.51) were associated with the increased risk of COVID-19 in the second and third trimesters of gestation. It was showed that systematic (once in the morning at 24–48-hour intervals) intranasal administration of recombinant interferon alpha-2b (IFN-α; Grippferon) as compared with a single application after exposure to COVID-19 reduced the disease incidence rate and there was no evident risk of illness (OR = 0.08; 95% CI 0.05–0.14; 19.2% vs 74,3%, p < 0.001). This can be explained by the fact that women were mostly infected in unpredictable conditions (e.g., 29.2% of pregnant women were infected from family members, 23.9% had unknown source of exposure). The use of umifenovir, not currently authorised for the medication-assisted prevention of COVID-19 in pregnant women, and rectal administration of IFN-α suppositories did not reduce the disease incidence rate. Rectal use of IFN-α suppositories by pregnant women off-label increased the incidence (32.0 vs 15.4%, p = 0.001) and risk of developing novel coronavirus infection (OR = 2.58; 95% CI 1.48–4.50). Conclusion. There is a need to improve awareness among pregnant women about the mandatory and timely vaccination against COVID-19 during pregnancy and the importance of strict adherence to wearing face masks. Increased efforts should be made to monitor and inform pregnant women about the use of only authorised medication-assisted preventive measures of SARS-CoV-2 infection, such as intranasal administration of recombinant IFN α-2b (Grippferon). During the epidemic rise in COVID-19 cases, the systematic intranasal administration of recombinant interferon-based medication Grippferon (once in the morning at 24–48-hour intervals) is recommended for pregnant women. Key words: pregnancy, COVID-19, incidence rate, vaccination, recombinant interferon alpha-2b, Grippferon, prevention