Second harmonic generation imaging as a potential tool for staging pregnancy and predicting preterm birth

Area of Science:

• Biomedical Engineering
• Obstetrics & Gynecology
• Materials Science

Background:

• Cervical remodeling is crucial for normal pregnancy progression.
• Preterm birth, a major complication, involves abnormal cervical changes.
• Understanding collagen's role in cervical remodeling is key to predicting preterm labor.

Purpose of the Study:

• To quantitatively assess collagen structural changes during normal pregnancy and in a preterm birth model using SHG microscopy.
• To identify early microscopic indicators of cervical remodeling.
• To differentiate normal from abnormal cervical remodeling associated with preterm birth.

Main Methods:

• Utilized second harmonic generation (SHG) microscopy to image collagen structure in murine cervix.
• Analyzed SHG images quantitatively for mean intensity, forward/backward intensity ratio, fiber size, and porosity.
• Compared collagen morphology in normal gestation with a preterm birth model.

Main Results:

• Significant collagen morphological changes observed throughout normal gestation.
• Early pregnancy shows alterations in mean SHG intensity and intensity ratio, indicating submicroscopic changes.
• Collagen fiber size increased, and porosity enlarged from early to late pregnancy.
• Premature cervical remodeling exhibited distinct collagen structural changes compared to normal remodeling.

Conclusions:

• SHG microscopy effectively quantifies collagen changes during cervical remodeling.
• Early microscopic collagen alterations precede macroscopic cervical changes in normal pregnancy.
• Distinct collagen structural patterns differentiate normal from preterm birth-associated cervical remodeling.
• SHG imaging holds potential for developing endoscopic tools for clinical assessment and preterm labor risk prediction.