Impact of SARS-CoV-2 vaccination on male sperm quality and fertility in the context of assisted reproductive technologies: a systematic literature review
Bibliographic record
Abstract
Abstract Context Widespread concern has emerged regarding the potential impact of COVID-19 vaccines on male fertility, particularly in the context of assisted reproductive technologies (ART). Objective This systematic review aims to evaluate the impact of SARS-CoV-2 vaccination on male sperm quality and its implications for fertility in couples undergoing in vitro fertilization (IVF) or intrauterine insemination (IUI). Design Systematic review of original research articles. Data sources For this systematic review, an exploration of relevant original research articles was performed through a literature search in the EMBASE, Cochrane and Medline databases, encompassing publications up to October 10th, 2023. Eligibility criteria Randomized controlled trials and observational studies on men of reproductive age who received a COVID-19 vaccine, with available semen analysis parameters. Data extraction and synthesis Data extraction and quality assessment were performed independently by two authors. Studies were assessed using the Newcastle–Ottawa Scale. Main outcome measures Semen volume, pH levels, sperm count/concentration, progressive motility, and morphology. Key results 18 original studies were included in our review. Findings showed that 11% of studies reported an increase in semen volume, while none reported a decrease. No studies reported an increase in pH, but 5% noted a decrease. For sperm count or concentration, 11% of studies reported an increase, and 5% reported a decrease, suggesting heterogeneous effects without a clear positive or negative trend. Progressive motility increased in 5% of studies but decreased in 11%. No studies reported improved sperm morphology, while 11% noted impairment. Sperm parameters were assessed at varying intervals post-second COVID-19 vaccination, with an average of 96 days (range: 1–9 months). All studies achieved satisfactory quality. Implications Given the varied research outcomes, there is a critical need for standardized and comprehensive studies to understand the impact of COVID-19 vaccination on male fertility. Further research targeting individuals with oligospermia is essential to comprehensively assess vaccine effects on fertility, while addressing identified study limitations is crucial for interpreting findings accurately and reliably.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.045 | 0.279 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".