University of Oulu

Junno, JA., Keisu, A., Niinimäki, M. et al. Gravidity, parity and knee breadth at midlife: a population-based cohort study. Sci Rep 12, 12415 (2022).

Gravidity, parity and knee breadth at midlife : a population-based cohort study

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Author: Junno, Juho-Antti1,2,3,4; Keisu, Asla1,2; Niinimäki, Maarit1,5,6;
Organizations: 1Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland
2Anatomy and Cell Biology, Cancer and Translational Medicine Research Unit, Faculty of Medicine, University of Oulu, P.O. Box 5000, 90014, Oulu, Finland
3Department of Archaeology, Faculty of Humanities, University of Oulu, Oulu, Finland
4Archaeology, Faculty of Arts, University of Helsinki, Helsinki, Finland
5Department of Obstetrics and Gynecology, PEDEGO Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland
6Department of Obstetrics and Gynecology, Oulu University Hospital, Oulu, Finland
7Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
8Center for Life Course Health Research, Faculty of Medicine, University of Oulu, Oulu, Finland
9Department of Forensic Medicine, Faculty of Medicine, University of Helsinki, Helsinki, Finland
10Forensic Medicine Unit, Finnish Institute for Health and Welfare, Helsinki, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1 MB)
Persistent link:
Language: English
Published: Springer Nature, 2022
Publish Date: 2023-02-15


Gestation increases the biomechanical loading of lower extremities. Gestational loading may influence anthropometrics of articular surfaces in similar means as bone diaphyseal properties. This study aimed to investigate whether gravidity (i.e. number of pregnancies) and parity (i.e. number of deliveries) is associated with knee breadth among middle-aged women. The study sample comprised 815 women from the Northern Finland Birth Cohort 1966. The median parity count of our sample was 2 and the median gravidity count 3. At the age of 46, questionnaires were used to enquire gravidity and parity, and posteroanterior knee radiographs were used to obtain two knee breadth parameters (tibial plateau mediolateral breadth (TPML) and femoral condylar mediolateral breadth (FCML)) as representatives of articular size. The associations of gravidity and parity with knee breadth were analyzed using general linear models with adjustments for height, weight, leisure-time physical activity, smoking, and education years. Individuals with osteoarthritic changes were excluded from our sample. The mean TPML in our sample was 70.3 mm and the mean FCML 71.6 mm respectively. In the fully adjusted models, gravidity and parity showed positive associations with knee breadth. Each pregnancy was associated with 0.11–0.14% larger knee breath (p < 0.05), and each delivery accounted for an increase of 0.20% in knee breadth (p < 0.01). Between-group comparisons showed that multiparous women had 0.68–1.01% larger knee breath than nulli- and primiparous women (p < 0.05). Pregnancies and deliveries seem to increase the mediolateral breadth of the knee. This increase is potentially associated with increased biomechanical loadings during gestation.

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Series: Scientific reports
ISSN: 2045-2322
ISSN-E: 2045-2322
ISSN-L: 2045-2322
Volume: 12
Article number: 12415
DOI: 10.1038/s41598-022-16231-1
Type of Publication: A1 Journal article – refereed
Field of Science: 3126 Surgery, anesthesiology, intensive care, radiology
Funding: NFBC1966 received financial support from University of Oulu (Grant no. 24000692), Oulu University Hospital (Grant no. 24301140), and ERDF European Regional Development Fund (Grant no. 539/2010 A31592).
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