Quantitative Microbiologic Models for Preterm Delivery

Abstract

Preterm delivery (PTD) is the leading cause of infant morbidity and mortality in the United States. An epidemiological association between PTD and various bacteria that are part of the vaginal microflora has been reported. No single bacterial species has been identified as being causally associated with PTD, suggesting a multifactorial etiology. Quantitative microbiologic cultures have been used previously to define normal vaginal microflora in a predictive model. These techniques have been applied to vaginal swab cultures from pregnant women in an effort to develop predictive microbiologic models for PTD. Logistic regression analysis with microbiologic information was performed for various risk groups, and the probability of a PTD was calculated for each subject. Four predictive models were generated by using the quantitative microbiologic data. The area under the curve (AUC) for the receiver operating curves ranged from 0.74 to 0.94, with confidence intervals (CI) ranging from 0.62 to 1. The model for the previous PTD risk group with the highest percentage of PTDs had an AUC of 0.91 (CI, 0.79 to 1). It may be possible to predict PTD by using microbiologic risk factors measured once the gestation period has reached the 20-week time point.The complex microflora of the human vagina is thought to play an important role in both health and disease. Although a great deal of quantitative and qualitative data describing the vaginal microflora are available, it is only recently that statistical models defining normal vaginal microflora have been developed (33). It has also been possible to predict, on the basis of these quantitative microbiologic models, when the vaginal microflora is abnormal (50, 51). Part of the modeling process is to identify microbial risk factors, such as an abnormal vaginal microflora (i.e., vaginal candidiasis or bacterial vaginosis [BV]), that are associated with a specific outcome. The application of these predictive statistical modeling techniques, using microbiologic data, to other outcomes such as preterm births is appealing because women at risk for adverse pregnancy outcomes might then be identified early during their pregnancies. Early identification of women at high risk for an adverse outcome would allow for interventional therapy to be directed only at such women.Preterm delivery (PTD) is the leading cause of infant morbidity and mortality in the United States (2, 12, 19). Preterm labor, premature rupture of membranes, and low birth weight have been associated with either specific maternal genital tract infections or an altered vaginal microflora during pregnancy (1,8,35,37,47,48). Because bacteria are thought to contribute to PTD, substances of bacterial origin thought to act as mediators of PTD have been sought. Organisms implicated in PTD include specific agents, such as Chlamydia trachomatis, Ureaplasma urealyticum, and Bacteroides and yeast species (13,30,32,33,54,55). A constellation of organisms representative of those associated with BV have also been cited as having the poten...

Analysis of adherence, biofilm formation and cytotoxicity suggests a greater virulence potential of Gardnerella vaginalis relative to other bacterial-vaginosis-associated anaerobes

“…Bacterial strains used in this study, references to their association with BV, and the source of the strains, are listed in Table 1. The strains were purchased from ATCC, isolated from confirmed cases of BV (confirmed by Amsel criteria and Nugent score; Holmes et al, 1981) at Brigham and Women's Hospital, Boston, MA, USA (Onderdonk et al, 2003), or isolated as part of this study from Virginia Commonwealth University (VCU) Women's Health Clinic. Strains from the VCU Women's Health Clinic were isolated from vaginal swab specimens taken from women diagnosed with BV by the Amsel criteria.…”

Vaginal infections among pregnant women at Omdurman Maternity Hospital in Khartoum, Sudan

“…Vaginal and cervical swabs samples were obtained from each subject using the standard sampling technique for microbiological investigation described by Onderdonk et al [13]. Three high vaginal swabs were collected from each patient by a gynecologist and placed into Amies transport medium.…”

Jenis dan Jumlah Mikroorganisme Aerob pada Persalinan Spontan Kurang dan Cukup Bulan tanpa Ketuban Pecah Dini

“…Onderdonk dkk. 9 menyimpulkan bahwa persalinan kurang bulan dapat terjadi apabila terdapat mikroorganisme patogen dengan jumlah yang cukup dan dapat diperkirakan dengan menghitung jumlah mikroorganisme sebagai skrining.…”

“…Penelitian ini sesuai dengan penelitian Onderdonk dkk. 9 Keterbatasan penelitian ini walaupun sudah dilakukan upaya menyingkirkan faktor perancu dengan kriteria inklusi dan eksklusi, tetapi tidak seluruhnya sempurna seperti misalnya pemeriksaan laboratorium hanya diambil pada saat penderita datang untuk persalinan, sebaiknya pemeriksaan tersebut diikuti sejak kunjungan pertama. Selain itu, standar baku pemeriksaan sebaiknya diambil…”