Effect of female coronavirus disease 2019 vaccination on assisted reproductive outcomes: a systematic review and meta-analysis.

IMPORTANCE: The effect of coronavirus disease 2019 (COVID-19) vaccination on fertility warrants clarification in women undergoing assisted reproductive treatment. OBJECTIVE: To study the association between female COVID-19 vaccination and outcomes of assisted reproductive treatment. DATA SOURCES: PubMed, Embase, the Web of Science, Cochrane Library, and medRxiv and bioRxiv were searched for eligible studies from December 1, 2019, to November 30, 2022, with no language restrictions. STUDY SELECTION AND SYNTHESIS: Observational studies comparing assisted reproductive outcomes between women with and without COVID-19 vaccination were included. The pooled estimates were calculated using the random-effects models as mean differences (MDs), standardized MDs, or odds ratios with 95% confidence intervals (CIs). Heterogeneity was evaluated using the I2 statistic. MAIN OUTCOMES: The number of oocytes retrieved and clinical pregnancy rate. RESULTS: Twenty-one cohort studies involving a total of 19,687 treatment cycles were included. In a comparison of the vaccinated vs. unvaccinated groups, the pooled MD for oocyte number was -0.06 (95% CI, -0.51 to 0.39; I2 = 0), and the pooled odds ratio for clinical pregnancy was 0.95 (95% CI, 0.85-1.05; I2 = 0). Similarly, there were no statistically significant adverse effects identified in other outcomes determined a priori, including 4 cycle characteristics, 6 laboratory parameters, and 3 pregnancy indicators. Most results were consistently unchanged in subgroup and sensitivity analyses, with no evidence of publication bias according to Egger's test. CONCLUSION AND RELEVANCE: Our work did not find significant differences in assisted reproductive outcomes between vaccinated and unvaccinated women. However, more data are warranted to confirm the safety of COVID-19 vaccination for assisted reproductive treatment and in female fertility in general.

Impact of inactivated SARS-CoV-2 vaccination on embryo ploidy: a retrospective cohort study of 133 PGT-A cycles in China.

BACKGROUND: Unsubstantiated concerns have been raised on the potential correlation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infertility, leading to vaccine hesitancy in reproductive-aged population. Herein, we aim to evaluate the impact of inactivated SARS-CoV-2 vaccination on embryo ploidy, which is a critical indicator for embryo quality and pregnancy chance. METHODS: This was a retrospective cohort study of 133 patients who underwent preimplantation genetic testing for aneuploidy (PGT-A) cycles with next-generation sequencing technology from June 1st 2021 to March 17th 2022 at a tertiary-care medical center in China. Women fully vaccinated with two doses of Sinopharm or Sinovac inactivated vaccines (n = 66) were compared with unvaccinated women (n = 67). The primary outcome was the euploidy rate per cycle. Multivariate linear and logistic regression analyses were performed to adjust for potential confounders. RESULTS: The euploidy rate was similar between vaccinated and unvaccinated groups (23.2 ± 24.6% vs. 22.6 ± 25.9%, P = 0.768), with an adjusted ß of 0.01 (95% confidence interval [CI]: -0.08-0.10). After frozen-thawed single euploid blastocyst transfer, the two groups were also comparable in clinical pregnancy rate (75.0% vs. 60.0%, P = 0.289), with an adjusted odds ratio of 6.21 (95% CI: 0.76-50.88). No significant associations were observed between vaccination and cycle characteristics or other laboratory and pregnancy outcomes. CONCLUSIONS: Inactivated SARS-CoV-2 vaccination had no detrimental impact on embryo ploidy during in vitro fertilization treatment. Our finding provides further reassurance for vaccinated women who are planning to conceive. Future prospective cohort studies with larger datasets and longer follow-up are needed to confirm the conclusion.

No Effect of Inactivated SARS-CoV-2 Vaccination on in vitro Fertilization Outcomes: A Propensity Score-Matched Study.

PURPOSE: To investigate the impact of inactivated SARS-CoV-2 vaccination on in vitro fertilization (IVF) outcomes. PATIENTS AND METHODS: This retrospective cohort study included 2185 patients undergoing fresh IVF cycles from June 1st to September 13th 2021 in a single university-affiliated hospital. Vaccine administration information was collected and ascertained via immunization records. Patients with two dosages of inactivated SARS-CoV-2 vaccines (Sinopharm or Sinovac) were categorized into the vaccinated group (n = 150), while those unvaccinated were classified as control (n = 2035). Propensity score matching was performed to balance the baseline characteristics (14 covariates) between the two groups at a ratio of 1:4. The main outcome measures were the number of oocytes retrieved, good-quality embryo rate and clinical pregnancy rate. RESULTS: There were 146 women in the vaccinated group and 584 in the control group after matching. The number of oocytes retrieved (9.9 ± 7.1 vs 9.9 ± 6.7; P = 0.893), good-quality embryo rate (33.5 ± 29.8% vs 29.9 ± 28.6%; P = 0.184) and clinical pregnancy rate (59.1% vs 63.6%; P = 0.507) were all similar between the two groups. In addition, no significant differences were observed regarding other cycle characteristics, laboratory parameters and pregnancy outcomes. The results were also comparable when vaccinated patients were subdivided into three categories based on the time interval from complete vaccination to cycle initiation: ≤1 month, >1-2 months, and >2 months. CONCLUSION: Our study provided the first-time evidence that inactivated SARS-CoV-2 vaccination in females did not result in any measurable detrimental effects on IVF treatment. Owing to the present limitations, further prospective studies with larger cohort size and longer follow-up are warranted to validate our conclusion.

The impact of air pollution on COVID-19 pandemic varied within different cities in South America using different models.

There is a rising concern that air pollution plays an important role in the COVID-19 pandemic. However, the results were not consistent on the association between air pollution and the spread of COVID-19. In the study, air pollution data and the confirmed cases of COVID-19 were both gathered from five severe cities across three countries in South America. Daily real-time population regeneration (Rt) was calculated to assess the spread of COVID-19. Two frequently used models, generalized additive models (GAM) and multiple linear regression, were both used to explore the impact of environmental pollutants on the epidemic. Wide ranges of all six air pollutants were detected across the five cities. Spearman's correlation analysis confirmed the positive correlation within six pollutants. Rt value showed a gradual decline in all the five cities. Further analysis showed that the association between air pollution and COVID-19 varied across five cities. According to our research results, even for the same region, varied models gave inconsistent results. For example, in Sao Paulo, both models show SO2 and O3 are significant independent variables, however, the GAM model shows that PM10 has a nonlinear negative correlation with Rt, while PM10 has no significant correlation in the multiple linear model. Moreover, in the case of multiple regions, currently used models should be selected according to local conditions. Our results indicate that there is a significant relationship between air pollution and COVID-19 infection, which will help states, health practitioners, and policy makers in combating the COVID-19 pandemic in South America.