Objective
Misinformation regarding Covid vaccination has contributed to vaccine hesitancy. Initially, there were claims that immune cross reactivity between the SARS CoV-2 spike protein and syncytin-1 would prevent embryo implantation. We previously demonstrated no difference in implantation and sustained implantation rates between previously vaccinated or infected women compared to other women.1
More recently, misinterpretation of vaccine biodistribution data has led to a second claim that mRNA containing lipid nanoparticles are concentrated in the ovaries and spike protein produced there would also cause infertility.
The purpose of this study is to determine whether prior in vivo ovarian exposure to lipid nanoparticle-mRNA vaccination against SARS-CoV2 spike protein reduces subsequent fertility in women.
Materials and Methods
This is an ongoing observational study of women undergoing frozen embryo transfer with a single expanded blastocyst. This is an interim report (n =128) encompassing transfers between Jan 1 and Jul 02. All patients had serum analyzed prior to starting stimulation for egg retrieval to quantitatively determine the level of Anti-SARS-CoV-2 Spike IgG. Reactive (antibody positive) patients were questioned to determine a history of vaccination or infection. Patients were divided into three groups based on their status. Women who were vaccinated (n = 26); women who had previous infection with SARS-CoV-2 (n=11) and women without a history of either vaccination or infection (n=91). Only patients receiving the mRNA vaccines from BioNTech / Pfizer (BNT162b2) and Moderna (mRNA-1273) were analyzed. Outcome measure for the three groups were initial implantation rate (serum hCG level > 5 mIU/mL obtained 8 days after embryo transfer followed by a rising level two to three days later), sustained implantation rate (transvaginal ultrasound documented positive FHTs at two time points at least one week apart) and miscarriage rate (the difference between initial and sustained implantation rates). Baseline characteristics were analyzed using ANOVA. Chi square analysis was used to compare pregnancy rates.
Results
| Non-reactive | Vaccination | Infection | P Value | |
|---|---|---|---|---|
| Total transfers | 91 | 26 | 11 | |
| Implantation rate | 86.8% (n=79) | 84.6% (n=22) | 90.9% (n=10) | 0.19 |
| Sustained implantation rate | 63.7% (n=58) | 61.5% (n=16) | 54.6% (n=6) | 0.10 |
| Miscarriage rate | 23.1% | 23.1% | 36.3% | 0.15 |
Conclusions
Embryos produced from oocytes exposed in vivo to lipid nanoparticles containing mRNA for the SARS CoV-2 spike protein are not less likely to produce pregnancy or more likely to miscarry.
Impact Statement
This data refutes the rumors that Covid-19 vaccinations are "toxic" to the ovaries & adds to the growing body of evidence that vaccinations do not cause infertility.
Support
None
Reference:
1. Morris RS. SARS-CoV-2 spike protein seropositivity from vaccination or infection does not cause sterility [published online ahead of print, 2021 Jun 2]. F S Rep. 2021.
O-190 11:30 AM Wednesday, October 20, 2021