Low-Field Magnetic Resonance Imaging of the Late Gestation Cervix and Birth Outcome Correlation: A Prospective Cohort Study

Simi Bansal; Alena U Uus; Agnieszka Glazewska-Hallin; Caitlin Allwin; Hadi Waheed; Vanessa Kyriakopoulou; Anna L David; Dimitrios Siassakos; Manju Chandiramani; Jana Hutter; Lisa Story; Mary A Rutherford

doi:10.1111/1471-0528.70103

Low-Field Magnetic Resonance Imaging of the Late Gestation Cervix and Birth Outcome Correlation: A Prospective Cohort Study

BJOG. 2025 Dec 3. doi: 10.1111/1471-0528.70103. Online ahead of print.

Authors

Simi Bansal^{1

2}, Alena U Uus¹, Agnieszka Glazewska-Hallin^{2

3}, Caitlin Allwin¹, Hadi Waheed^{2

4}, Vanessa Kyriakopoulou^{1

2}, Anna L David⁴, Dimitrios Siassakos⁴, Manju Chandiramani^{2

3}, Jana Hutter^{2

5}, Lisa Story^{3

6}, Mary A Rutherford^{1

2}

Affiliations

¹ School of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
² Reseach Department for Early Life Imaging, King's College London, London, UK.
³ Department of Women and Children's Health, King's College London, London, UK.
⁴ Elizabeth Garrett Anderson Institute for Women's Health, University College London, London, UK.
⁵ Smart Imaging Lab, Radiological Institute, University Hospital Erlangen, Erlangen, Germany.
⁶ Fetal Medicine Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK.

PMID: 41332358
DOI: 10.1111/1471-0528.70103

Abstract

Objective: To use low-field MRI to produce reconstructions and 3D models of the cervix and to automate measurements for correlation with demographics and birth outcomes.

Design: Prospective cohort study.

Setting: KCL Advanced Imaging Centre, St Thomas's Hospital.

Population: Late gestation (36-41w) women attempting their first vaginal birth, recruited to the MiBirth study (n = 97).

Methods: Reconstructed images were produced from 2D T2-weighted Turbo-Spin-Echo 2D sequences acquired with a 0.55 T Freemax MRI scanner. Segmentations and anatomical landmarks were automated using an in-house 3D deep learning segmentation network, from which cervical 2D measurements and 3D volumes were generated.

Main outcome measures: Quality of reconstructed images and segmentations. Inter-rater variability for cervical biometry. Correlation between cervical measurements, maternal demographics and birth outcomes.

Results: Successful reconstructions were obtained for 92.9%; 84.9% were good quality. Excellent or good quality segmentations were obtained for all successful reconstructions (n = 99). Inter-rater variability between automated and manual biometry was excellent or good for cervical measurements. Total cervical and stroma volumes significantly increased with cervical length (p < 0.01). Os diameters and utero-cervical angle significantly decreased as cervical length increased (p < 0.001). Cervical stroma volume increased with maternal age (p = 0.02). Controlling for maternal age, an increased cervical volume was associated with an increased risk of caesarean section (OR 1.09, p = 0.04).

Conclusions: This is a novel, accurate automated system to assess MRI late gestation cervical biometry and volumetry. We have shown that the late gestation cervical phenotype may influence birth outcomes and provided a new mechanism for increased risk of caesarean with maternal age.

Keywords: birth outcomes; cervix; magnetic resonance imaging; pregnancy MRI.

Abstract

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