569 A novel technique using raman spectroscopy for assessing cervical change during labor

Abstract

We sought to use Raman spectroscopy, a light-based technology, for in vivo assessment of changes in the biochemical composition of the cervix as a function of labor progression based on spectral data. Pregnant women without history of cervical insufficiency, preterm labor, or rupture of membranes were recruited upon admission to labor and delivery. Demographic data including age, BMI, parity, and gestational age at delivery were collected. Raman spectroscopy measurements, using a fiber optic probe placed on the cervical face, were serially acquired during routine cervical exams until rupture of membranes. Generalized linear models using a restricted cubic spline with 65 degrees of freedom were fit to the data and spectral features were analyzed using generalized estimating equations. 30 women were included in the study, with average age of 27 years, BMI of 32, and gestational age of 39 weeks at delivery (Table 1). Raman spectral signatures associated with collagen, located at 1265, 1441, and 1650 cm-1, decreased approaching delivery. Similar decreases in peaks associated with actin and other proteins are noted, indicating a decline in extracellular matrix protein (ECM) concentration (Figure 1A). The ratio of 1657 to 1668 cm-1 increased closer to delivery, corresponding to collagen fiber reorientation and decreasing compactness. A greater extent of spectral change across all regions was observed in nulliparous compared to multiparous patients, suggesting a greater extent of cervical remodeling in the nulliparous population (Figure 1B). Patients with a BMI >30 at term displayed less change in spectral features associated with collagen compared to BMI<30 (Figure 1C). Raman spectroscopy objectively probes changes in chemical composition, identifying decreases in collagen, actin, and other ECM proteins as the cervix prepares for delivery. This technique shows differences in the cervical remodeling process based on parity and BMI, demonstrating the potential to quantitatively evaluate labor progression and utility for assessing cervical insufficiency in the future.View Large Image Figure ViewerDownload Hi-res image Download (PPT)