Heterogeneous microstructural changes of the cervix influence cervical funneling

Area of Science:

• Reproductive biology
• Biomedical engineering
• Biophysics

Background:

• The cervix maintains pregnancy but abnormal remodeling can cause preterm birth (PTB).
• Previous studies have not fully characterized the complex 3D microstructure of the cervix during pregnancy.
• Understanding cervical microstructural changes is crucial for identifying PTB risk factors.

Purpose of the Study:

• To investigate the 3D microstructural remodeling of the rat cervix during pregnancy.
• To determine if cervical remodeling is uniform across different regions.
• To explore the relationship between microstructural changes and cervical funneling, a marker for PTB risk.

Main Methods:

• Quantitative 3D second-harmonic generation microscopy to image cervical microstructure.
• Finite element simulation to model the mechanical impact of microstructural changes.
• Analysis of collagen fiber orientation and regional tissue properties.

Main Results:

• Cervical remodeling during pregnancy is heterogeneous, with collagen fibers reorienting perpendicularly to the canal in the inner cervical zone.
• Initially distinct cervical regions become more similar in microstructure as pregnancy progresses.
• Simulations show heterogeneous remodeling significantly influences cervical funneling, with the inner cervical zone's fiber orientation playing a key role.

Conclusions:

• Cervical microstructural remodeling is region-specific and dynamic during pregnancy.
• The orientation of collagen fibers in the inner cervical zone is critical for maintaining cervical integrity and preventing premature dilation.
• These findings provide new insights into PTB mechanisms and support further clinical research on cervical funneling.