Cervical Light-induced Fluorescence Research Articles

Evaluation of cervical maturity by cervical collagen measurement using light-induced fluorescence (LIF) during pregnancy.

ObjectiveThe study aimed to evaluate cervical ripening by measuring cervical collagen levels in non-pregnant women, women with a normal pregnancy, and postpartum women by light-induced fluorescence (LIF).MethodsCervical collagen content in normal pregnant women (n = 165) at various times of gestation was measured by LIF with a collascope, which is specifically designed to measure fluorescence of collagen. Cervical LIF in non-pregnant women (n = 12) and postpartum women (n = 14) was also detected. The demographic characteristics of women at various times were recorded. The Bishop score at 40 to 41 gestational weeks (n = 37) before the onset of labor was analyzed.ResultsCervical LIF values progressively declined from the non-pregnant state to late gestation (R = −0.836) and reached their lowest levels during parturition and then increased at postpartum. LIF values and the Bishop score were significantly negatively correlated (R = −0.83). In patients with a Bishop score ≥6, the first stage of labor was shortened with a decrease in LIF values (R = 0.718).ConclusionsCervical collagen levels as measured by LIF could be a useful method for evaluating cervical maturity.

Diagnosis and Effective Management of Preterm Labor

Despite extensive research, we are still unable to diagnose, prevent and treat preterm labor. Monitoring efficacy of interventions that would allow this is largely biased by the inability to accurately identify true labor with the currently used crude technology. Progestin supplementation appears to be a promising approach to both preventing initiation of preterm labor and treating it once it is already established, given progesterone’s role in maintaining pregnancy as well as support from basic and clinical research. However, the questions on mechanisms of action, optimal progestin formulation, dose, route and timing of administration remain unanswered. We have established and reported noninvasive means to accurately monitor cervical ripening, by measuring collagen light-induced fluorescence (LIF) and myometrial contractility, by measuring uterine electromyo graphy (EMG). By accurately assessing the two components of parturition, cervical LIF and uterine EMG can help to identify effective prevention strategies and treatment of preterm labor.

Assessment of Parturition with Cervical Light-Induced Fluorescence and Uterine Electromyography

Parturition involves increasing compliance (ripening) of the uterine cervix and activation of the myometrium. These processes take place in a different time frame. Softening and shortening of the cervix starts in midpregnancy, while myometrial activation occurs relatively close to delivery. Methods currently available to clinicians to assess cervical and myometrial changes are subjective and inaccurate, which often causes misjudgments with potentially adverse consequences. The inability to reliably diagnose true preterm labor leads to unnecessary treatments, missed opportunities to improve neonatal outcome, and inherently biased research of treatments. At term, the likelihood of cesarean delivery depends on labor management, which in turn depends on accurate assessments of cervical change and myometrial contractility. Studies from our group and others show that noninvasive measurements of light-induced fluorescence (LIF) of cervical collagen and uterine electromyography (EMG) objectively detect changes in the composition of the cervix and myometrial preparedness to labor and are more reliable than clinical observations alone. We present a conceptual model of parturition constructed on cervical LIF and uterine EMG studies. We also explore how these methodologies could be helpful with managing patients experiencing preterm contractions and with optimizing labor management protocols aimed to reduce cesarean section.

Uterine EMG and Cervical LIF - Promising Technologies in Obstetrics

No current objective measures exist to determine uterine or cervical function during pregnancy, or to accurately predict term or preterm labor and delivery. Uterine electromyography (EMG) and cervical light-induced fluorescence (LIF) studies were performed in term and pre-term animals and humans to evaluate the state and function of the uterus and cervix, and to determine the predictive capability of measurements made using these new technologies. Both uterine EMG and cervical LIF produced high positive and negative predictive values, compared to other currently-used methods. Uterine EMG and cervical LIF show great promise as diagnostic tests during pregnancy and for patient monitoring in obstetrics.

Light-induced fluorescence of the human cervix decreases after prostaglandin application for induction of labor at term

Objective To define the changes in cervical light-induced fluorescence (LIF), an index of cross-linked collagen, after the use of locally applied prostaglandin preparations for labor induction at term and the correlation between LIF and Bishop-Score. Study design The characteristic LIF of cervical collagen was measured from the surface of the cervix using a specially designed instrument (collascope) in 41 gravidas undergoing labor induction at term by prostaglandins. LIF and Bishop-Score were obtained directly before and 4 h after the administration of prostaglandin. Paired Student's t-test, Wilcoxon Signed Rank test, Linear Regression, Spearman correlation and Fisher Exact test were used as appropriate. Results Cervical LIF decreased significantly after prostaglandin application (0.982 ± 0.04 [before] to 0.885 ± 0.037 [after], p = 0.025). The decrease in LIF correlated with the initial LIF before PG-application ( r = 0.61). The Bishop-Score increased in all 41 patients. No correlation was found between LIF versus Bishop-Score. Conclusions Cervical application of prostaglandins decreases the amount of cross-linked collagen as measured by LIF. This effect was observed only in patients with a prior high cross-linked collagen.

Use of uterine EMG and cervical LIF in monitoring pregnant patients

Review the uterine electromyography (EMG) and cervical light-induced fluorescence (LIF) devices and their role in the evaluation of uterine and cervical function in comparison with present methods. Review of recent studies. University of Texas Medical Branch Labour and Delivery Clinics. Various groups of pregnant women. We have developed and recently improved non-invasive methods to evaluate quantitatively uterine electrical signals from the abdominal surface and cervical collagen. Uterine EMG utilised power density spectrum (PDS) peak frequency and total power (P(0)) and cervical LIF utilising LIF ratio. Human studies indicate that uterine and cervical performance can be successfully monitored during pregnancy using EMG and LIF, respectively, and the assessment of uterine and cervical function can both be used to influence patient management in a variety of conditions associated with labour, more than can currently available methods. The potential benefits of the proposed instrumentation include the following: a reduction in the rate of preterm birth, improved maternal and perinatal outcome, better monitoring of treatment, decreased caesarean section rate and better research methods for understanding uterine and cervical function.

Cervical light-induced fluorescence in pregnant women with cervical insufficiency

Cervical light-induced fluorescence in pregnant women with cervical insufficiency

Platelet-activating factor antagonist WEB-2170 inhibits lipopolysaccharide-induced, but not antiprogestin-induced, preterm cervical ripening in timed-pregnant rats

Objective The purpose of this study was to determine whether the platelet-activating factor antagonist WEB-2170 inhibits preterm cervical ripening induced by lipopolysaccharide or by antiprogestin RU 486. Study design Timed-pregnant rats were killed on day 16 after treatment with (1) WEB-2170, lipopolysaccharide, lipopolysaccharide plus WEB-2170, or vehicle control and (2) with WEB-2170, RU 486, RU 486 plus WEB-2170, or vehicle control. Cervical ripening was assessed by light-induced fluorescence and resistance to stretch. Statistics were assessed by 1-way analysis of variance followed by Tukey-test ( P < .05). Results Light-induced fluorescence and resistance to stretch were significantly lower in the lipopolysaccharide-treated and in the RU486-treated animals compared with vehicle control (lipopolysaccharide:light-induced fluorescence, 7.0±0.6 vs 12.8±0.8 [ P = .001]; resistance to stretch, 0.41±0.03 N/mm vs 0.54±0.04 N/mm [ P < .05]; RU486:light-induced fluorescence, 9.6±0.6 vs 11.7±0.6 [ P < .05]; resistance to stretch, 0.28±0.06 N/mm vs 0.61±0.02 N/mm [ P < .001]). Compared with vehicle control, WEB-2170 alone did not alter cervical light-induced fluorescence or resistance to stretch. Although WEB-2170 significantly blocked cervical ripening after lipopolysaccharide administration (light-induced fluorescence, 11.3±1.3 [ P < .05]; resistance to stretch, 0.61±0.04 [ P < .01]), WEB-2170 did not inhibit the RU 486–induced cervical ripening. Conclusion Although infection-related cervical ripening is inhibited by platelet-activating factor antagonists, the physiologic process of cervical ripening appears to be unaffected. Platelet-activating factor inhibition may be of clinical value in the infection-related pathologic processes that are responsible for premature cervical ripening.

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.)

462 The time to delivery interval can be estimated by measurement of cervical light-induced fluorescence

462 The time to delivery interval can be estimated by measurement of cervical light-induced fluorescence