Title: The impact of SARS-COV-2 infection on menstruation
Version: 0 Date: 22 Aug 2023
Reviewer:  Phuc Nhon Nguyen
Reviewer's report:
Dear  authors,
Congratulation. Thank you for your report concerning about women's health in Covid-19
pandemic. The methology is suitable with Covid-infected and non-infected group as well as
subgroup including AUB and non-AUB in each groups.  The number of  participants is totally
large, even in the non-infected Covid group remained limited. This may cause  a limitation.
I understand well the diificulties of study with the questionaire survey which missed a lot
of required information. However,  BMC Women's Health  is reputative journal (Q2) with
high IF and strict criteria, thus, I need to send you some necessary comments in constructive
way.Through the paper, I have suspected some important points as below:
- Abnormal uterine bleeding (definition, diagnosis, management, its burdens to women, etc...)
should be expanded in Background. Refer to this reference:  Nguyen, P. N., & Nguyen, V. T.
(2022). Evaluating Clinical Features in Intracavitary Uterine Pathologies among Vietnamese
Women Presenting with Peri-and Postmenopausal Bleeding: A Bicentric Observational
Descriptive Analysis. Journal of mid-life health, 13(3), 225–232. https://doi.org/10.4103/
jmh.jmh_81_22
-Study sample size calculation should be included.
-How the authors excluded the women in transtional period prior to perimenopausal who had
AUB due to ovulational disorders?
- The symptoms of perimenopause and premenopause period can not differentiate from the
Covid-19 symptoms. Please mentioned on this entity.
-The table should include all types of AUB following FIGO classification or the  previous term.
-The type of vaccination may impact on the symptoms and immune system. The authors did not
discuss about it and did not include in the survey.
-If the participants had examinated for exclusion from malignant and benign intrauterine
pathologies by ultrasound? The authors can read these papers:
+Nguyen, P. N., & Nguyen, V. T. (2022). Endometrial thickness and uterine artery Doppler
parameters as soft markers for prediction of endometrial cancer in postmenopausal bleeding
women: a cross-sectional study at tertiary referral hospitals from Vietnam. Obstetrics &
gynecology science, 65(5), 430–440. https://doi.org/10.5468/ogs.22053
+Nguyen, P. N., & Nguyen, V. T. (2023). Additional value of Doppler ultrasound to B-
mode ultrasound in assessing for uterine intracavitary pathologies among perimenopausal and
postmenopausal bleeding women: a multicentre prospective observational study in Vietnam.
Journal of ultrasound, 26(2), 459–469. https://doi.org/10.1007/s40477-022-00732-w
-Anemia and hemoglobine levels are absent from the result. Please add these variables. Anemia
can cause some related symptoms.
- How the women can estimate the blood loss (by tampon, pad per day, or menstrual carlendar,
etc...). Please describe this issue in the method.
-The study only included the Chinese population, so this must be a limitation in ethnic
epidemiology.
Finally,  although the conclusion is focused,  and some studies have mentioned on this issue:
+Lebar V, Laganà AS, Chiantera V, Kuni# T, Lukanovi# D. The Effect of COVID-19 on the
Menstrual Cycle: A Systematic Review. J Clin Med. 2022;11(13):3800. Published 2022 Jun 30.
doi:10.3390/jcm11133800
+Sharp, G. C., Fraser, A., Sawyer, G., Kountourides, G., Easey, K. E., Ford, G., Olszewska, Z.,
Howe, L. D., Lawlor, D. A., Alvergne, A., & Maybin, J. A. (2022). The COVID-19 pandemic
and the menstrual cycle: research gaps and opportunities. International journal of epidemiology,
51(3), 691–700. https://doi.org/10.1093/ije/dyab239
I suspect with the conclusion that vaccination reduced the AUB, the evidence is not enough
strong. And the participants with chest pain and dyspnea are more likely to develop AUB, these
symptoms are totally subjected, depend on the severity of Covid-infection, vaccination, age, and
misconducting signs of Covid-19 and  perimenopausal  physical changes.
Best regards,