{
  "abstract": "Background: Accumulating epidemiological and andrological evidence has raised concerns about potential long-term declines in semen quality worldwide, highlighting the need for sustained, population-specific surveillance. In this study, we retrospectively analyzed temporal changes in semen quality during the period of 2021–2025 amid the COVID-19 pandemic. This work extends our previous report on annual trends in semen quality at the same center from 2015 to 2021.\n\nMethods: This retrospective study evaluated temporal changes in semen quality parameters among 21,932 men who attended a reproductive center in Shanghai between 2021 and 2025, a period characterized by widespread COVID-19 pandemic. After 2–7 days of sexual abstinence, semen samples were analyzed using computer-assisted sperm analysis to assess conventional semen parameters, including semen volume, sperm count, sperm concentration, and sperm motility, as well as sperm kinematic parameters, including curvilinear velocity, straight-line velocity, average path velocity, and beat-cross frequency. To better characterize temporal changes across different baseline semen-quality strata, participants were classified according to the WHO 2010 reference criteria into above-reference-limit and below-reference-limit groups. Differences among groups were assessed using one-way analysis of variance, the Kruskal–Wallis test, independent-samples t-test, and analysis of covariance, as appropriate. In the above-reference-limit group, multiple linear regression models including year, age, and abstinence duration were used to adjust for potential confounders and evaluate temporal trends in semen quality.\n\nResults: In the overall cohort and in both the above-reference-limit and below-reference-limit subgroups, sperm count, sperm concentration, and several CASA-derived kinematic parameters, including curvilinear velocity, straight-line velocity, average path velocity, and beat-cross frequency, generally showed increasing temporal trends from 2021 to 2025. After adjustment for age and abstinence duration, multiple linear regression analyses in the above-reference-limit group supported these associations. Semen volume, sperm count, sperm concentration, curvilinear velocity, straight-line velocity, average path velocity, and beat-cross frequency increased significantly over the study period, with regression coefficients of 0.0876, 4.815, 0.6929, 0.9423, 0.3553, 0.5150, and 0.1172, respectively. In contrast, sperm motility decreased significantly over time, with a regression coefficient of −0.7112.\n\nConclusion: The observed increases in semen volume, sperm count, and sperm concentration contrast with the declining trends previously reported at the same reproductive center before the COVID-19 pandemic. These findings suggest widespread COVID-19 pandemic have reversed the annual changes in parameters related to semen quality.",
  "abstract_shown": true,
  "affiliations": [
    "International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University",
    "Shanghai Key Laboratory of Embryo Original Diseases"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Shiyi Zhu"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Jin Dong"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhengmu Wu"
    },
    {
      "affs": [
        0
      ],
      "name": "Zhengquan Wang"
    },
    {
      "affs": [
        0
      ],
      "name": "Jun Yang"
    },
    {
      "affs": [
        0
      ],
      "name": "Chao Feng"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Chunhua Tang"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Yuchuan Zhou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a40ann57ya1rr.bib",
  "cited_by": 0,
  "doi": "10.3389/fendo.2026.1980263",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13719297/?tool=EBI",
  "id": "a40ann57ya1rr",
  "issns": [
    "1664-2392"
  ],
  "landing_url": "https://www.frontiersin.org/articles/10.3389/fendo.2026.1980263/full",
  "language": "eng",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Original Research"
    ],
    [
      "openalex",
      "2743|Sperm and Testicular Function"
    ]
  ],
  "openalex": "W7222690815",
  "pdf_url": "https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2026.1980263/pdf",
  "pmcid": "PMC13719297",
  "pmid": "42964052",
  "published": "2026-10-16",
  "publisher": "Frontiers Media SA",
  "ris": "https://research.draconitic.com/paper/a40ann57ya1rr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:20Z",
      "native_id": "10.3389/fendo.2026.1980263",
      "source": "crossref",
      "url": "https://www.frontiersin.org/articles/10.3389/fendo.2026.1980263/full"
    },
    {
      "first_seen": "2026-10-31T12:21:36Z",
      "native_id": "PMC:PMC13719297",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13719297"
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    {
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  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2743|Sperm and Testicular Function",
      "subfield": "reproductive-child"
    }
  ],
  "title": "Temporal trends in semen quality at a single reproductive center in Shanghai, China, during 2021–2025 amid the COVID-19 pandemic",
  "title_text": "Temporal trends in semen quality at a single reproductive center in Shanghai, China, during 2021–2025 amid the COVID-19 pandemic",
  "type": "peer-reviewed",
  "updated_at": "2026-11-03T12:20:23Z",
  "url": "https://research.draconitic.com/paper/a40ann57ya1rr",
  "venue": "Frontiers in Endocrinology",
  "versions": []
}