Stopping the misinformation: BNT162b2 COVID-19 vaccine has no negative effect on women’s fertility

  1. Myriam Safrai
  2. Amihai Rottenstreich
  3. Shmuel Herzberg
  4. Tal Imbar
  5. Benjamin Reubinoff
  6. Assaf Ben-Meir

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Abstract

Objective

To investigate the possible impact of Pfizer-BioNTech’s mRNA BNT162b2 COVID-19 vaccine on women’s fertility.

Methods

A retrospective single-center study examining women’s IVF treatment parameters and pregnancies before and after their vaccination between February and May 2021. Each woman served as a self-control before and after vaccination. Additionally, in order to neutralize the effect of the sperm on fertilization, only Intracytoplasmic Sperm Injection (ICSI) patients who were currently being treated with an ICSI cycle and had an earlier ICSI cycle available were included in the study. The study outcomes compared between the PRE and POST vaccination groups and consisted of: the IVF cycle outcomes, including the number of oocytes retrieved; the number of matured oocytes; the fertilization rate; and the number and quality of embryos at day 3. Clinical pregnancy was based on the first hCG value reported if the data were available for both cycles.

Results

A final total of 47 women were eligible for inclusion with a mean interval of 362 ±368 days between the two ovum pick ups. The characteristics of their ICSI cycles before and after the vaccination were similar for all the parameters. Additionally, the number and percentage of clinical pregnancies did not significantly differ between the PRE and POST vaccination groups (n=15).

Conclusion

This study is the first to evaluate the impact of the BNT162b2 vaccine on women’s fertility. From our findings, the vaccine appears to have no impact on women’s fertility. This study is the first step in abolishing the misinformation derived from unreliable sources and reassuring patients in order to improve compliance and promote COVID-19 eradication.

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  1. ScreenIT

    SciScore for 10.1101/2021.05.30.21258079: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Ethical approval: Approval was obtained from the institutional review board (IRB) of the Hadassah-Hebrew University Medical Center before data extraction was performed.
    Consent: The requirement for written informed consent was waived by the IRB.
    Sex as a biological variableData obtained included: patient demographics (age and body mass index (BMI)); indication for IVF treatment (i.e. female/male factor, unknown infertility, and need for pre-implantation genetic diagnosis (PGD) or fertility preservation); follicle stimulating hormone (FSH) value; data regarding the IVF cycle (length of gonadotropin (GT) stimulation and total GT dose, estrogen level on the day before ovum pick up (OPU), the number of oocytes retrieved, the number of mature oocytes, the number of fertilized oocytes, the number and quality of embryos at day 3); and the time since the first dose of the vaccine.
    Randomizationnot detected.
    Blindingnot detected.
    Power AnalysisA sample size of 32 women (in the entire cohort) was required to detect a significant difference of 30% in the number of oocytes retrieved (probability of Type 1 error of 0.05 and 80% power).

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    All statistical analyses were carried out using Excel 2013.
    Excel
    suggested: None

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Our study has several limitations. The main one is the retrospective nature of the analysis of the PRE vaccine group. This carries an inherent selection bias and information bias due to the medical record coding. Another potential caveat is the relatively small sample size of the study population. Nevertheless, the sound methodology where each patient served as their own self-control strengthens the results and allows us to provide reliable answers to the questions raised regarding the effects of BNT162b2 vaccination on fertility. Finally, we included data on the pregnancy rate in a subgroup of the study sample (n=15). This is a small group but we included this data as it strengthens our findings showing no differences in IVF treatment parameters before and after vaccination and moreover it directly analyzes women’s fertility. There is an inherent bias in considering the pregnancy rate; couples whose previous ICSI cycle ended in pregnancy are less likely to return for another cycle. The mean interval between both OPU was 362 days. The impact of such a period of time on fertility differs depending on the age of the patient; namely, it is more significant in older women. However, no such fertility differences were seen in our study. If any such differences had in fact shown, we would expect reduced fertility of the POST group. Clearly, a larger study is warranted to validate these initial findings demonstrating that the BNT162b2 vaccination does not impact women’s fertility. In...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.05.30.21258079v1 on medRxiv