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Regarding: COVID-19 vaccination during pregnancy: coverage and safety

Published:October 23, 2021DOI:https://doi.org/10.1016/j.ajog.2021.10.027
      To the Editors:
      We read with great interest the article titled “COVID-19 vaccination during pregnancy: coverage and safety” by Blakeway et al
      • Blakeway H.
      • Prasad S.
      • Kalafat E.
      • et al.
      COVID-19 vaccination during pregnancy: coverage and safety.
      , and we appreciate the authors for conducting this study at a particularly crucial point of time to make vaccine safety data available for clinicians. We, however, would like to make some observations to help comprehend the study better.
      The study reveals that among the vaccinated antenatal population, 3 women eventually developed SARS-CoV-2 infection. It would be highly informative if you could further elaborate on the duration between the administration of the vaccine and the development of infection, the type of vaccine given, and the severity of disease in these women. It is also mentioned that the vaccine was administered to 1 woman with underlying cardiac disease. We would like to know the particulars of the lesion and whether any thromboprophylaxis was given postvaccination. Table 3 indicates that among the unvaccinated population, 1 woman had a stillbirth. It would be highly appreciated if we are given information about the cause of the same, in particular whether it was related to SARS-Cov-2 infection or febrile illness.
      We also seek come clarifications regarding a few statistical figures. Table 3 shows the perinatal outcomes among the women who received the vaccine antenatally vs those who did not. Among the 133 women who received at least 1 dosage during pregnancy, 3 developed SARS-CoV-2 infections; when they are excluded, it makes a cohort of 130. However, in Table S1, the strength of this cohort is 131.
      Assuming that Table S1 is a subset of Table 3, it is confusing to us that the number of women who had fetal abnormalities (12 vs 11), cesarean deliveries (133 vs 122), and neonatal intensive care unit admissions (23 vs 21) among the unvaccinated women in Table S1 exceeds that of Table 3. We would be grateful to you if you could shed some light on the same.
      Moreover, under the results section, it is stated that there was a statistically significant trend of a reduced vaccine uptake among women of the African-Caribbean and Asian ethnicity than those of Caucasian background (page 14, line 25). However, the P value for the Asian ethnicity was .183, which was not statistically significant.
      We would also like to know the background behind choosing a blood loss cutoff of 1 L as the definition of postpartum hemorrhage. It would significantly exclude many cases falling between 1 L cutoff and the World Health Organization-defined cutoff of 500 mL for vaginal deliveries.
      World Health Organization
      Human Reproduction Programme. WHO recommendations on prevention and treatment of postpartum haemorrhage.

      References

        • Blakeway H.
        • Prasad S.
        • Kalafat E.
        • et al.
        COVID-19 vaccination during pregnancy: coverage and safety.
        Am J Obstet Gynecol. 2021; ([Epub ahead of print])
        • World Health Organization
        Human Reproduction Programme. WHO recommendations on prevention and treatment of postpartum haemorrhage.
        (Available at:) (Accessed August 14, 2021)