{
  "abstract": "Purpose: Macrosomia is associated with adverse maternal and neonatal outcomes, but early risk stratification remains challenging. Most existing prediction approaches rely on later-pregnancy ultrasound measurements, limiting opportunities for earlier preventive counseling and monitoring. Methods: In this secondary analysis of the prospective nuMoM2b cohort in the United States, we included 6,371 nulliparous singleton pregnancies selected for available periconceptional diet and ultrasound data at Visits 2 and 3. We developed visit-updated multivariable logistic regression models for birthweight >4000 g and >4500 g using routinely available maternal characteristics, anthropometry, periconceptional diet, and serial ultrasound measurements, with sensitivity analyses using large-for-gestational-age birthweight. Model performance was assessed by repeated stratified cross-validation and compared with World Health Organization fetal growth chart-based ultrasound percentile benchmarks, emphasizing the estimated fetal weight percentile as the most clinically familiar proxy. Results: Birthweight >4000 g and >4500 g occurred in 7.9% and 1.2% of pregnancies, respectively. Models updated with later pregnancy information achieved the best discrimination, with an area under the receiver operating characteristic curve of 0.73 for birthweight >4000 g and 0.82 for birthweight >4500 g. In this selected analytic cohort, the early-pregnancy model based on maternal data alone provided moderate discrimination (0.63 and 0.72, respectively), although lower than the strongest third-trimester WHO fetal growth chart-based ultrasound percentile benchmarks. Conclusion: Within this selected cohort, routinely available early-pregnancy maternal characteristics and anthropometry provided moderate risk stratification for macrosomia, and later ultrasound measurements improved performance further. Estimates for birthweight >4500 g require caution given the 77 events. External validation is required before clinical implementation.",
  "abstract_shown": true,
  "affiliations": [
    "Eindhoven University of Technology"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Y. Wu"
    },
    {
      "name": "M. van der Ven"
    },
    {
      "name": "E. Peri"
    },
    {
      "name": "S. Asvadi"
    },
    {
      "name": "M. B. van der Hout-van der Jagt"
    },
    {
      "name": "S. G. Oei"
    },
    {
      "name": "M. Mischi"
    },
    {
      "affs": [
        0
      ],
      "name": "X. Long"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/787fyaa3c5vh6.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.29.26366704",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.10.29.26366704v1.full",
  "id": "787fyaa3c5vh6",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.10.29.26366704v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "obstetrics and gynecology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.10.29.26366704v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/787fyaa3c5vh6.ris",
  "sources": [
    {
      "first_seen": "2026-10-31T00:20:43Z",
      "native_id": "10.64898/2026.10.29.26366704",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.10.29.26366704v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:obstetrics and gynecology",
      "subfield": "reproductive-child"
    }
  ],
  "title": "Development and internal validation of early- and mid-pregnancy prediction models for macrosomia in nulliparous singleton pregnancies",
  "title_text": "Development and internal validation of early- and mid-pregnancy prediction models for macrosomia in nulliparous singleton pregnancies",
  "type": "preprint",
  "updated_at": "2026-11-01T00:20:33Z",
  "url": "https://research.draconitic.com/paper/787fyaa3c5vh6",
  "venue": "medRxiv",
  "versions": []
}