Yasemin Üstündağ1*, Elif Güler Kazancı1, Emine Sevgican3, Canan Erdem4, Kagan Huysal5
Background: In the COVID-19 pandemic, the prevention and control of COVID-19 infection are extremely important. Therefore, laboratory indicators are needed that can detect pregnant patients with mild symptoms or no symptoms at the time of admission to the hospital and ensure that these patients are separated from the healthy population. This study aimed to review hematologic parameters in pregnant women with COVID-19 and evidence for their prognostic and diagnostic value. Methods: We searched PubMed/Medline, Scopus, and Google Scholar for the term “pregnancy” in combination with “COVID-19,” “coronavirus 2019” and “SARS-CoV-2” in studies published in the English literature between March 2020 and January 2021 and identified a number of studies. Studies that reported complete blood cell counts in pregnant patients with COVID-19 infection were selected. Both retrospective and prospective studies were included in this review, whereas case reports, cohort studies with less than 10 participants, and duplicate reports were excluded. A power analysis was not performed in any of the included studies. Results: Fourteen studies were found that evaluated hematologic parameters in pregnant women with COVID-19. A review of these studies revealed conflicting findings in terms of the potential diagnostic and prognostic value of following hematologic parameters in healthy pregnant women versus pregnant COVID-19 patients on admission to the hospital: the White Blood Cell (WBC) count, neutrophil, platelet, eosinophil and lymphocyte counts, and Neutrophil-to-Lymphocyte Ratio (NLR). WBC count in pregnant women with COVID-19 infection was significantly higher than that in non-pregnant women with COVID-19 infection. There was no difference in the lymphocyte counts of the pregnant and non-pregnant population with COVID-19, suggesting that lymphopenia may be a prognostic factor independent of pregnancy. Conclusion: In terms of their diagnostic value, the hematologic parameters evaluated did not distinguish healthy pregnant women from those with COVID-19 infection.