Factors affecting pubic symphysis separation in the third trimester of pregnancy: An observational cohort study
DOI:
https://doi.org/10.37800/RM.2.2026.782Keywords:
pubic symphysis, symphysiopathy, pregnancy, bone mineral density, logistic regression, risk factorsAbstract
Relevance: The pubic symphysis is remodeled in pregnancy as a result of hormonal, metabolic, and biomechanical changes. However, the separation of the pubic symphysis bones in pregnant women varies and may be influenced by numerous maternal factors.
The study aimed to determine factors associated with separation of the pubic symphysis during the third trimester of pregnancy by using a logistic regression model.
Materials and Methods: The study group consisted of 172 women in the third trimester of pregnancy. The distance between the pubic bones was measured by ultrasound. Bone mineral density (BMD) was measured by ultrasound osteodensitometry with the SONOST-3000 device (OsteoSys Co., Ltd., South Korea). The effect of different factors was assessed using univariate and multivariate logistic regression models.
Results: The logistic regression model was statistically significant (p < 0.001) and explained 27.4% of the probability of separation between the pubic symphysis bones. Decreased bone mineral density was the strongest independent predictor of pubic symphysis separation in multivariate analysis (AOR = 3.91; 95% CI: 1.85–8.24; p < 0.001). In addition, increased risk of separation was associated with a higher number of pregnancies (AOR = 1.79; 95% CI: 1.22–2.66; p = 0.003). Maternal age was protective, with older women less likely to have pubic symphysis separation (AOR = 0.45; 95% CI: 0.21–0.98; p = 0.045).
Conclusion: Low bone mineral density, a high number of pregnancies, and maternal age are independent predictors of pubic symphysis separation in the third trimester of physiological pregnancy. Timely detection of women at risk enables dynamic ultrasound control of the pubic symphysis and prevents symphysiopathy.
References
1. Stolarczyk A, Stępiński P, Sasinowski Ł, Czarnocki T, Dębiński M, Maciąg B. Peripartum pubic symphysis diastasis: Practical guidelines. J Clin Med. 2021;10(11):2443.
https://doi.org/10.3390/jcm10112443
2. Wang Y, Li YQ, Tian MR, Wang N, Zheng ZC. Role of relaxin in diastasis of the pubic symphysis peripartum. World J Clin Cases. 2021;9(1):91-101.
https://doi.org/10.12998/wjcc.v9.i1.91
3. Chen P, Lin W. Dynamic changes in pubic symphysis and superior pubic ligament during pregnancy: A study using ultrasound shear-wave elastography. Int J Womens Health. 2025;17:2195-2204.
https://doi.org/10.2147/IJWH.S520999
4. Zhang S, Dumas G, Hemmerich A. Measurement of pubic symphysis width using ultrasound. J Biomech. 2020;113:110114.
https://doi.org/10.1016/j.jbiomech.2020.110114
5. Bjelland EK, Stuge B, Engdahl B, Eberhard-Gran M. The effect of emotional distress on persistent pelvic girdle pain after delivery: A longitudinal population study. BJOG. 2013;120(1):32-40.
https://doi.org/10.1111/1471-0528.12029
6. Алтымова А., Аманжолқызы А., Губашева Г., Донаева А., Кульжанова Д., Каримсакова Б., Космуратова Ш. Дисфункция лонного сочленения: что мы знаем и что еще предстоит узнать. (обзор литературы). Репрод Мед (Центр Азия). 2025;1:57-66.
Altymova A, Amanzholkyzy A, Gubasheva G, Donayeva A, Kulzhanova D, Karimsakova B, Kosmuratova, S. Symphysis pubis dysfunction: What we know and still have to learn (a literature review). Reprod Med Centr Asia. 2025;1:57-66. Russian.
https://doi.org/10.37800/RM.1.2025.435
7. Воробьев А.А., Селихова М.С., Яковенко М.С. Современный взгляд на проблему симфизиопатии во время беременности. Якут Мед Журн. 2020;3(71):101-104.
Vorobyev AA, Selikhova MS, Yakovenko MS. A modern view on the problem of symphysiopathy during pregnancy. Yakut Med J. 2020;3(71):101-104. Russian.
https://doi.org/10.25789/YMJ.2020.71.26
8. Ianniello S, Conte P, Di Serafino M, Miele V, Trinci M, Vallone G, Galluzzo M. Diagnostic accuracy of pubic symphysis ultrasound in the detection of unstable pelvis in polytrauma patients during e-FAST: The value of FAST-PLUS protocol. A preliminary experience. J Ultrasound. 2021;24(4):423-428.
https://doi.org/10.1007/s40477-020-00483-6
9. Петрушин А.Л., Прялухина А.В. РАСХОЖДЕНИЕ ЛОННОГО СОЧЛЕНЕНИЯ ПРИ БЕРЕМЕННОСТИ И РОДАХ (ОБЗОР ЛИТЕРАТУРЫ). Травматология и ортопедия России. 2018; 24(3):145-156.
Petrushin AL, Pryaluchina AV. Pubic symphysis diastasis in pregnancy and delivery (review). Traumatol Orthop Russ. 2018;24(3):145-156. Russian.
https://doi.org/10.21823/2311-2905-2018-24-3-145-156
10. Wozniak S, Piatek A, Kurc-Darak B, Domagala Z, Paulsen F, Florjanski J. Sonographic evaluations of the pubic symphysis at different stages of pregnancy. J Clin Med. 2025;14(11):3898.
https://doi.org/10.3390/jcm14113898
11. Sakamoto A, Gamada K. Altered musculoskeletal mechanics as risk factors for postpartum pelvic girdle pain: A literature review. J Phys Ther Sci. 2019;31(10):831-838.
https://doi.org/10.1589/jpts.31.831
12. Heim JA, Vang S, Lips E, Asche SE, Ly T, Das K. Pubic symphysis separation and regression in vaginal versus cesarean delivery. J Obstet Gynaecol Can. 2022;44(1):42-47.
https://doi.org/10.1016/j.jogc.2021.07.015
13. Gausel AM, Malmqvist S, Andersen K, Kjærmann I, Larsen JP, Dalen I, Økland I. Subjective recovery from pregnancy-related pelvic girdle pain the first 6 weeks after delivery: A prospective longitudinal cohort study. Eur Spine J. 2020;29(3):556-563.
https://doi.org/10.1007/s00586-020-06288-9
14. Asuka S, Akino A, Tsuyoshi M, Kazuyoshi G. Association of pelvic alignment and posture in pregnancy with lower back or pelvic girdle pain during postpartum recovery: Myth or reality? A systematic review. J Gynecol Womens Health. 2021;21(5):556074.
https://doi.org/10.19080/JGWH.2021.21.556074
15. Kristiansson P, Zöller B, Dahl N, Kalliokoski P, Hallqvist J, Li X. Heredity of pregnancy-related pelvic girdle pain in Sweden. Acta Obstet Gynecol Scand. 2023;102(10):1250-1258.
https://doi.org/10.1111/aogs.14646
16. Starzec-Proserpio M, Lipa D, Szymański J, Szymańska A, Kajdy A, Baranowska B. Association among pelvic girdle pain, diastasis recti abdominis, pubic symphysis width, and pain catastrophizing: A matched case-control study. Phys Ther. 2022;102(4):pzab311.
https://doi.org/10.1093/ptj/pzab311
17. Elden H, Gutke A, Kjellby-Wendt G, Fagevik-Olsen M, Ostgaard HC. Predictors and consequences of long-term pregnancy-related pelvic girdle pain: A longitudinal follow-up study. BMC Musculoskelet Disord. 2016;17:276.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 А. Аманжолқызы, А.Қ. Алтымова, Д.С. Кульжанова, С.К. Балмагамбетова
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The articles published in this Journal are licensed under the CC BY-NC-ND 4.0 (Creative Commons Attribution – Non-Commercial – No Derivatives 4.0 International) license, which provides for their non-commercial use only. Under this license, users have the right to copy and distribute the material in copyright but are not permitted to modify or use it for commercial purposes. Full details on the licensing are available at https://creativecommons.org/licenses/by-nc-nd/4.0/.
