Cervical light-induced fluorescence in humans decreases throughout gestation and before delivery: Preliminary observations

Objective: The purpose of this study was to investigate gestational changes of cervical light-induced fluorescence, an index of cross-linked collagen, and the relationship between light-induced fluorescence and the time-to-delivery interval. Study design: Fifty patients were included in one of two groups. (1) Twenty-one healthy pregnant women without signs of labor underwent repeated cervical light-induced fluorescence measurement during the last trimester. (2) Light-induced fluorescence was measured in 29 patients with signs of labor, and the time from measurement to delivery was noted. Cervical light-induced fluorescence was obtained noninvasively with a prototype instrument that was designed specifically for this purpose. Spearman correlation and the Student t test and receiver-operator characteristics analysis were performed (P< .05). Results: Light-induced fluorescence correlated negatively with gestational age and positively with time-to-delivery interval, was significantly lower in patients who were delivered <24 hours compared with those patients who were delivered >24 hours later, and was predictive of delivery within 24 hours. Conclusion: Cervical light-induced fluorescence decreases significantly as gestational age increases. Light-induced fluorescence may be a useful tool to identify patients in whom delivery is imminent. (Am J Obstet Gynecol 2003;188:537-41.)