{
  "abstract": "Estimating the remaining time to delivery could aid intrapartum counseling. We derived a model relating the intrapartum angle of progression (AOP) to this interval in Korean nulliparous women in active labor. In this prospective study, 102 women with singleton, term, cephalic pregnancies were enrolled at the first examination documenting cervical dilatation ≥ 6 cm. Twenty-two underwent intrapartum cesarean delivery; the remaining 80, all of whom had spontaneous vaginal delivery, formed the derivation cohort. The predictor was enrollment AOP, and the outcome was log-transformed time to delivery (TTD). Higher enrollment AOP was associated with a shorter remaining time: β = − 0.134 per 1° (95% CI, − 0.166 to − 0.102); TTD = exp(21.04 − 0.134 × AOP); optimism-corrected R2 = 0.44 (95% CI, 0.26–0.63); optimism-corrected calibration slope = 1.01 (95% CI, 1.00–1.05); and median absolute error = 36 min (95% CI, 26–43). Fetal station as recorded in routine practice explained essentially none of the variation in ln(TTD): apparent R2 = 0.001 (95% CI, 0.000–0.049); adding enrollment AOP increased the apparent R2 by 0.498 (95% CI, 0.364–0.641). The study was not registered. This single-center derivation model estimates TTD conditional on subsequent spontaneous vaginal delivery and requires external validation before clinical use.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Obstetrics and Gynecology, Institute of Women’s Life Medical Science, Yonsei University College of Medicine",
    "Department of Obstetrics and Gynecology, Chung-Ang University College of Medicine",
    "Department of Obstetrics and Gynecology, Kyung Hee University College of Medicine"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Hayan Kwon"
    },
    {
      "affs": [
        1
      ],
      "name": "Yoomin Kim"
    },
    {
      "affs": [
        2
      ],
      "name": "Young-Joo Lee"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/012h53dp9mj6h.bib",
  "cited_by": 0,
  "doi": "10.1038/s41598-026-68656-7",
  "fulltext_url": "https://doi.org/10.1038/s41598-026-68656-7",
  "id": "012h53dp9mj6h",
  "issns": [
    "2045-2322"
  ],
  "landing_url": "https://doi.org/10.1038/s41598-026-68656-7",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "Q"
    ],
    [
      "lcc",
      "R"
    ],
    [
      "openalex",
      "2729|Maternal and Perinatal Health Interventions"
    ]
  ],
  "openalex": "W7204654179",
  "pdf_url": "https://www.nature.com/articles/s41598-026-68656-7_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-01",
  "publisher": "Nature Portfolio",
  "ris": "https://research.draconitic.com/paper/012h53dp9mj6h.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:45:47Z",
      "native_id": "9f1b18b58add4a658c0b017b8a61b238",
      "source": "doaj",
      "url": "https://doi.org/10.1038/s41598-026-68656-7"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2729|Maternal and Perinatal Health Interventions",
      "subfield": "reproductive-child"
    }
  ],
  "title": "Derivation of a time-to-delivery model using enrollment angle of progression in Korean nulliparous women with subsequent spontaneous vaginal delivery",
  "title_text": "Derivation of a time-to-delivery model using enrollment angle of progression in Korean nulliparous women with subsequent spontaneous vaginal delivery",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:45:47Z",
  "url": "https://research.draconitic.com/paper/012h53dp9mj6h",
  "venue": "Scientific Reports",
  "versions": []
}