COVID-19 vaccination did not impair fertility, early pregnancy outcomes or sperm quality, according to findings from three studies presented at the American Society for Reproductive Medicine Scientific Congress & Expo.

“We all know firsthand how the COVID-19 pandemic has changed the landscape of health care,” Devora Aharon, MD, a fellow in reproductive endocrinology and infertility at Icahn School of Medicine at Mount Sinai, said during a presentation. “Vaccination presents a path forward through the pandemic. However, there is still a high prevalence of vaccine hesitancy nationwide.”

IVF outcomes

Aharon and colleagues conducted a retrospective cohort study to assess possible effects of the Pfizer-BioNTech and Moderna COVID-19 vaccines on early pregnancy outcomes among women undergoing in-vitro fertilization. The study included 169 patients who underwent a single euploid frozen-thawed embryo transfer (FET) from February to July, 14 days or more following a second vaccine dose. Aharon and colleagues also included a control group of 657 unvaccinated patients who underwent an FET. Baseline age, oocyte age and BMI were similar between vaccinated and unvaccinated individuals.

Pregnancy rates were comparable between the groups: 74.6% among vaccinated individuals and 74.7% among unvaccinated individuals. In addition, clinical pregnancy rates, which the researchers defined as visualization of the gestational sac on an ultrasound, were identical at 63.8%.

The researchers observed no significant differences in pregnancy loss rates (20.3% vs. 22.4%) or clinical pregnancy loss (13.7% vs. 13.1%) between vaccinated vs. unvaccinated participants.

Aharon and colleagues concluded that there was no significant association between COVID-19 vaccination and pregnancy rates, clinical pregnancy rates or pregnancy loss. However, the researchers said they did not evaluate whether women were previously infected with SARS-CoV-2 and their antibody levels.

“The administration of COVID-19 mRNA vaccines does not interfere with implantation in patients who undergo single euploid FET,” Aharon said.

Data ‘refute the rumors’

In a similar study, Randy S. Morris, MD, medical director of IVF1 at the University of Chicago, and Alex J. Morris, an undergraduate student at IVF1, analyzed whether prior in-vivo ovarian exposure to an mRNA COVID-19 vaccine reduced fertility in women who underwent FET between Jan. 1 and Aug. 13.

In the ongoing observational study, patients had their serum analyzed for anti-SARS-CoV-2 antibodies prior to egg retrieval. They were then divided into groups based on their antibody status: vaccinated (n = 48), previously infected (n = 15) or neither (n = 116).

An interim analysis showed that embryos from oocytes exposed to mRNA COVID-19 vaccination were not less likely to produce pregnancy or more likely to miscarry. The implantation rate was 74.2% in unvaccinated and uninfected women, 78.6% in vaccinated women and 77.8% in previously infected women, and the sustained implantation rate was 50%, 57.1% and 44.4%, respectively, according to the researchers.

The findings “refute the rumors that COVID-19 vaccinations are ‘toxic’ to the ovaries,” the researchers wrote.

These rumors are “based on purposeful misinterpretation of biodistribution data,” R. Morris said during the presentation.

Sperm quality

In a third study, Daniel Gonzalez, a medical student at the University of Miami School of Medicine, and colleagues conducted a single-center prospective cohort study on the effect of mRNA COVID-19 vaccines on sperm quality.

“As COVID-19 vaccination in the U.S. opens to children and adolescents, evaluating any potential impact of the vaccine on male reproduction is imperative for public reassurance,” Gonzalez said during a presentation. “We hypothesized that since both vaccines only contain mRNA SARS-CoV-2 spike protein without the biologic ability to replicate the actual virus, the vaccines would not decrease semen parameters.”

The cohort included 45 men who provided semen samples after 2 to 7 days of abstinence prior to receiving the first COVID-19 vaccine dose and then again about 72 days following the second dose. The men ranged in age from 18 to 50 years and were considered healthy.

Sperm concentration and total motile sperm count did not significantly decline following COVID-19 vaccination, according to Gonzalez and colleagues. However, 12 men experienced a marginal, yet insignificant, decrease. The other 33 men demonstrated normal sperm parameters following COVID-19 vaccination. Also, eight men with oligospermia did not experience a decrease in spermatogenesis after they received the vaccine, Gonzalez said. Only one man demonstrated an abnormal total motile sperm count of less than nine after vaccination.

In this first evaluation of male fertility following mRNA COVID-19 vaccination, Gonzalez said that the “vaccines do not negatively impact male fertility potential.”

References:

Gonzalez D, et al. P-453. Presented at: American Society of Reproductive Medicine Scientific Congress & Expo; Oct. 17-20, 2021; Baltimore (hybrid meeting).

Lee JA, et al. O-177. Presented at: American Society of Reproductive Medicine Scientific Congress & Expo; Oct. 17-20, 2021; Baltimore (hybrid meeting).

Morris AJ, et al. O-190. Presented at: American Society of Reproductive Medicine Scientific Congress & Expo; Oct. 17-20, 2021; Baltimore (hybrid meeting).