Researchers found no associations between the Pfizer-BioNTech and Moderna mRNA vaccines and adverse effects on stimulation or early pregnancy outcomes with IVF, according to a study published in Obstetrics & Gynecology.

“This is one of the largest studies to review fertility and IVF cycle outcomes in patients who received COVID-19 vaccinations,” author Devora A. Aharon, MD, a fellow in reproductive endocrinology and infertility at Icahn Mount Sinai and Reproductive Medicine Associates of New York, said in a press release.

Devora A. Aharon

Researchers conducted a retrospective cohort study that included patients at RMA of New York who received controlled ovarian hyperstimulation or single euploid frozen-thawed embryo transfer between February and September 2021.

The new study builds on findings reported in October 2021 at the ASRM Scientific Congress & Expo, which involved a smaller number of patients who were examined between February and July 2021.

Vaccinated patients had received two doses of the Pfizer-BioNTech or Moderna vaccines 14 days or more before the start of their fertility treatments.

In an adjusted analysis, Aharon and colleagues found no association between COVID-19 vaccination and fertilization rate (B = 0.02 ± 0.02) among the 222 vaccinated and 983 unvaccinated patients who had controlled ovarian hyperstimulation cycles.  

The researchers also found no association between COVID-19 vaccination and eggs retrieved (B = 0.01 ± 0.57), mature oocytes retrieved (B = 0.26 ± 0.47), mature oocytes ratio (B = 0.02 ±  0.01), blastulation rate (B = 0.02 ± 0.02) or euploid rate (B = 0.05 ± 0.03).

Further, the researchers examined associations between vaccination and pregnancy, defined as a positive pregnancy test on blood work; clinical pregnancy, defined as a pregnancy seen on ultrasound; and ongoing pregnancy, meaning a healthy pregnancy that continued with discharge to the obstetrician at approximately 8 to 9 weeks gestation.

The researchers found no association between COVID-19 vaccination and clinical pregnancy (adjusted OR = 0.79; 95% CI, 0.54-1.15) among the 214 vaccinated and 733 unvaccinated patients who had single euploid frozen-thawed embryo transfer, with no statistically significant differences between the groups. Chances did not change because of vaccination.

Additionally, there was no significant association between COVID-19 vaccination and pregnancy (aOR = 0.88; 95% CI, 0.58-1.33), ongoing pregnancy (aOR = 0.9; 95% CI, 0.61-1.31), biochemical pregnancy loss (aOR = 1.21; 95% CI, 0.69-2.14) or clinical pregnancy loss (aOR = 1.02; 95% CI, 0.51-2.06).

“This study found no significant differences in response to ovarian stimulation, egg quality, embryo development or pregnancy outcomes between the vaccinated compared to unvaccinated patients,” said Aharon. “Our findings that vaccination had no impact on these outcomes should be reassuring to those who are trying to conceive or are in early pregnancy.”

Reference:

• Aharon D, et al. Obstet Gynecol. 2022;doi:10.1097/AOG.0000000000004713.