The purpose of this study was to determine the relationship between C-reactive protein (CRP) levels and intraamniotic infection in 48 women presenting with preterm labor and intact membranes. Blood samples for CRP tests were obtained immediately before the performance of transabdominal amniocentesis. The prevalence of amniotic fluid cultures positive for organisms was 14.6%. In 16 women (33.3%) positive CRP levels were obtained. There were no significant differences in the prematurity rate or the prevalence of microbial invasion of the amniotic cavity between women with positive CRP levels and women with negative levels. The sensitivity, specificity, and positive and negative predictive values for the detection of amniotic infection were 71.5%, 73.2%, 31.3% and 93.8%, respectively. Based on these results, we suggest that in women with preterm labor and negative CRP levels, routine amniocentesis may not be essential to the initial workup.
Mazor, M., Kassis, A., Horowitz, S., Wiznitzer, A., Kuperman, O., Meril, C., & Glezerman, M. (1993). Relationship between C-reactive protein levels and intraamniotic infection in women with preterm labor. The Journal of reproductive medicine, 38(10), 799-803.
Mazor M, Kassis A, Horowitz S, Wiznitzer A, Kuperman O, Meril C, et al. Relationship between C-reactive protein levels and intraamniotic infection in women with preterm labor. J Reprod Med. 1993;38(10):799-803.
Mazor, M., et al. "Relationship between C-reactive protein levels and intraamniotic infection in women with preterm labor." The Journal of reproductive medicine, vol. 38, no. 10, 1993, pp. 799-803.
Keywords
Adult, C-Reactive Protein/analysis, Chorioamnionitis/blood/microbiology, Female, Gestational Age, Humans, Obstetric Labor, Premature/blood/microbiology, Pregnancy, Pregnancy Complications, Infectious/blood/microbiology, Sensitivity and Specificity, C-Reactive Protein
C-reactive protein (CRP) is the prototype acute-phase protein, which can increase up to 1000-fold after the onset of a stimulus. Aside from its disputed role as a marker of infection and/or inflammation in daily clinical practice, the protein has a wide variety of biological properties and functions. Due to its opsonizing abilities and its capability to activate human complement, CRP plays an important role in the innate host defense against different microorganisms, such as bacteria and fungi. The same opsonophagocyting properties can lead to clearance of host cell material, including nuclear constituents. Inflammation is one of the cornerstones in the etiology and pathogenesis of atherosclerosis, which led to worldwide attention being focused on CRP and its role in the process of atherosclerosis. This role may have a dual character. First, CRP levels reflect the 'burden' of inflammation within atherosclerotic lesions, thus reflecting the grade of vulnerability and instability of the plaques. For this reason, an increased level of the protein may be a prelude to rupture of the plaque and, thus, to occlusive arterial disease. Secondly, CRP may play an active role in the atherosclerotic process. CRP plays a role in the expression of different adhesion molecules on endothelial cells and the protein is able to activate human complement within the plaque. Furthermore, the recent discovery of local production of CRP and complement proteins within the plaque suggests an active role for the protein in the inflammatory cascade. Whatever the role for CRP in the atherosclerotic process, it has been proven that an elevated CRP level, with a cut-off point of approximately 3 mg/l, is associated with an increased risk of occlusive arterial disease, especially acute coronary syndromes.
In this study we evaluated different markers of infection and their relationship to preterm delivery. Forty-four consecutive women with singleton pregnancies in uncomplicated preterm labor were investigated. C-reactive protein (CRP) in peripheral maternal blood, amniotic fluid cytokines, amniotic fluid leukocyte count, and amniotic fluid culture were performed in all patients. Thirty-six patients responded to standard tocolytic therapy and delivered after 34 weeks' gestation. In eight patients treatment failed and they delivered before 34 weeks' gestation. Two of these eight patients had a positive amniotic fluid culture for Ureaplasma urealyticum. The positive culture was accompanied by an elevated neutrophil count in the amniotic fluid. Elevated amniotic fluid levels of tumor necrosis factor (TNF) (more than 23 pg/mL), interleukin-6 (IL-6) (more than 2292 pg/mL) and interleukin-8 (more than 164 pg/mL) correlated with early preterm delivery. CRP levels in serum had a low sensitivity (38%) but a high specificity (94%) in predicting preterm delivery. This study indicates that preterm labor can be initiated by infection. Markers of infection obtained by amniocentesis have a better sensitivity and positive predictive value than noninvasive markers. Elevated IL-6 (more than 2292 pg/mL) seems to be the best predictor for preterm delivery, with a sensitivity of 75% and a specificity of 97%.
PregnancyInfection BiomarkersTocolysis OutcomesC-Reactive Protein in Pregnancy
Tocolytics were administered in 66 consecutive women in uncomplicated preterm labour with intact fetal membranes (53 singleton and 13 twin pregnancies). C-reactive protein (CRP), a marker of infection, was determined daily and used retrospectively to investigate the role of subclinical infection in preterm labour and to predict the efficacy of tocolysis and the development of a clinical perinatal infection. CRP was also determined in 66 women in uncomplicated labour at term (53 singleton and 13 twin pregnancies). The placenta was examined for histological evidence of infection in all patients who were delivered before 36 weeks (n = 21) and in all women in the control group (n = 66). Elevated CRP levels were more often found in patients who were refractory to tocolysis, suggesting an underlying infectious morbidity. Placental infection was found in 62% of the preterm delivery group and in 12% of the control group. There was an association between elevated CRP levels and histological evidence of placental infection. However, confounding factors such as urinary tract infections limit the usefulness of the CRP test. Because CRP cannot predict clinical perinatal infection accurately, its clinical relevance is very limited.
General OB/GYNInfection MarkersC-Reactive ProteinDiagnosis and Management
This study was designed to derive the predictive value of C-reactive protein (CRP) in peripheral venous serum of patients admitted to hospital with suspected premature rupture of the membranes (PROM). CRP was assayed by each of 4 separate methods and the results have been compared for accuracy and practical value with respect to clinical outcome and the histopathology of the placenta. Of the 4 techniques used only the latex test had characteristics suitable for a diagnostic screen. While the results were only semiquantitative, when comparisons were made to other techniques no significant change in clinical diagnosis would have been made. The results have confirmed that chorioamnionitis and preterm labour are often associated, but in some instances the extent of inflammatory infiltration was greater than might have been expected from the short time interval between documented membrane rupture and delivery. Thus it may be speculated that some cases of PROM are secondary to, rather than causative of, infection. Finally it is suggested that a controlled therapeutic trial of active intervention in those cases of PROM with elevated CRP in the absence of other clinical parameters suggestive of intrauterine infection should be undertaken.