Blood Type Associated with the Risk of COVID-19 Infection in Pregnant Women
, Johnatan Torres-Torres 1, Rafael Velazquez-Cruz 3, José Esteban Muñoz-Medina 4, Claudia Martinez-Cordero 5 and Alberto Hidalgo-Bravo 6,*Round 1
Reviewer 1 Report
The ms is too long especially for the importance of the findings. I would suggest to shorten it. A few remarks on the SARS-CoV-2 infection of the newborn. Did the authors found any protection againts the virus by breast feeding? Any information regarding antibodies towards the virus in the breast milk? T-test in the statistics is not a very strong tool. The results should be discussed according to this statement. I would be very carefull by taking conclusions with in total of 18 individuals expressing the BG AB.
Author Response
Reviewer 1
Comments and Suggestions for Authors
The ms is too long especially for the importance of the findings. I would suggest to shorten it.
We appreciate the reviewer’s comments, we have shortened the methods sections as recommended. We would prefer to leave the technical details regarding SARS-CoV-2 detection for reproducibility by other authors.
A few remarks on the SARS-CoV-2 infection of the newborn. Did the authors found any protection againts the virus by breast feeding? Any information regarding antibodies towards the virus in the breast milk?
We are thankful with the reviewer’s comment. Some of the authors involved in the article are preparing a manuscript analyzing breast milk and presence of antibodies. Since the aim of this work does not involve immunological factors the antibody detection is beyond the scope of our investigation. In addition, in the newborns, the sample recollection was performed immediately after birth, before their first breast feeding.
T-test in the statistics is not a very strong tool. The results should be discussed according to this statement.
We appreciate the reviewer’s observation. We performed the Student’s t test only for age comparisons. If this is the referee’s observation, we have performed D’Agostino-Pearson Test for verifying data distribution. Only the data from the individuals in the group of a positive test did not show normal distribution. Therefore, we performed a Mann–Whitney U test for median comparison between the individuals with positive and negative test. The test did not show a significant difference, p=0.7182. Based on these results we did not modify the results presented regarding the age comparisons.
For the association of the blood groups with the outcomes, positive test, severe disease and death, we performed a logistic regression as stated in the methods section. While for proportion comparison we utilized a Pearson´s chi-square test as mentioned in the methods section. We have discussed the results based on these tests.
I would be very carefull by taking conclusions with in total of 18 individuals expressing the BG AB.
We understand the reviewer’s concern. We have added the following sentence in the discussion section:
“Therefore, the presence of blood group AB in pregnant women with SARS-CoV-2 infection could may lead to a more severe form of the disease. However, these results should be taken with caution since the number of AB individuals is small in our study population.”
Reviewer 2 Report
The manuscript describes a study carried out on 1,906 pregnant women with the aim to evidence a possible association, in this population, between SARS-CoV-2 test positivity and blood groups.
The study is, from the methodological point of view, well organized and documented.
Even if this topic has been yet described in many populations, a limited number of studies have been reported in pregnant women.
The study has some limitations (576 SARS-CoV-2 positive subjects and very small number of AB group individuals), but these aspects are clearly underlined in the text.
Author Response
Reviewer 2
Comments and Suggestions for Authors
The manuscript describes a study carried out on 1,906 pregnant women with the aim to evidence a possible association, in this population, between SARS-CoV-2 test positivity and blood groups.
The study is, from the methodological point of view, well organized and documented.
Even if this topic has been yet described in many populations, a limited number of studies have been reported in pregnant women.
The study has some limitations (576 SARS-CoV-2 positive subjects and very small number of AB group individuals), but these aspects are clearly underlined in the text.
We appreciate the reviewer’s comments. We agree with the observations described and therefore we addressed them in the limitations section.
