Chorioamnionitis and colonization of the newborn infant with genital mycoplasmas

The Role of Ureaplasma Species in Prenatal and Postnatal Morbidity of Preterm Infants: Current Concepts

BACKGROUND

Ureaplasma species are considered commensals of the adult urogenital tract. Yet, in pregnancy, Ureaplasma parvum and Ureaplasma urealyticum have been associated with chorioamnionitis and preterm birth. In preterm infants, Ureaplasma respiratory tract colonization has been correlated with the development of bronchopulmonary dysplasia and has been implicated in the pathogenesis of other complications of prematurity. Controversies on the impact of Ureaplasma exposure on neonatal morbidity, however, remain, and recommendations for screening practices and therapeutic management in preterm infants are missing.

SUMMARY

In this review, we outline clinical and experimental evidence of Ureaplasma-driven fetal and neonatal morbidity, critically examining inconsistencies across some of the existing studies. We explore underlying mechanisms of Ureaplasma-associated neonatal morbidity and discuss gaps in the current understanding including the interplay between Ureaplasma and the maternal urogenital tract and the preterm airway microbiome. Ultimately, we highlight the importance of adequate diagnostics and review the potential efficacy of anti-infective therapies.

KEY MESSAGES

There is strong evidence that perinatal Ureaplasma exposure is causally related to the development of bronchopulmonary dysplasia, and there are conclusive data of the role of Ureaplasma in the pathogenesis of neonatal central nervous system infection. Observational and experimental findings indicate immunomodulatory capacities that might promote an increased risk of secondary infections. The burden of Ureaplasma exposure is inversely related to gestational age - leaving the tiniest babies at highest risk. A better knowledge of contributing pathogen and host factors and modulating conditions remains paramount to define screening and treatment recommendations allowing early intervention in preterm infants at risk.

Chorioamnionitis: An Update on Diagnostic Evaluation

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Perinatal Infections With Ureaplasma

Ureaplasma species are increasingly recognized as relevant pathogens in prenatal, perinatal and postnatal morbidity. They are commonly found as commensals on the mucous membranes of the lower urogenital tract of pregnant women, but when ascending, they can cause bacterial vaginosis, chorioamnionitis, premature birth and postnatal morbidities such as bronchopulmonary dysplasia, and early-onset neonatal sepsis and meningitis. The detection of Ureaplasma species is challenging and is not covered by routine diagnostics, and current empiric antibiotic treatment in neonates suspected of infection is not directed against Ureaplasma species. The aim of this review is to discuss the pathophysiology of Ureaplasma infections, the clinical consequences and the current difficulties in diagnosis and treatment by providing an overview of the current literature.

Vaginotypes of the human vaginal microbiome

The human vaginal environment harbours a community of bacteria that plays an important role in maintaining vaginal health and in protecting this environment from various urogenital infections. This bacterial population, also known as vaginal microbiota, has been demonstrated to be dominated by members of the Lactobacillus genus. Several studies employing 16S rRNA gene-based amplicon sequencing have classified the vaginal microbiota into five distinct community state types (CSTs) or vaginotypes. To deepen our understanding of the vaginal microbiota we performed an in-depth meta-analysis of 1312 publicly available datasets concerning healthy vaginal microbiome information obtained by metagenomics sequencing. The analysis confirmed the predominance of taxa belonging to the Lactobacillus genus, followed by members of the genera Gardnerella, Vibrio and Atopobium. Moreover, the statistical robustness offered by this meta-analysis allowed us to disentangle the species-level composition of dominant and accessory taxa constituting each vaginotype and to revisit and refine the previously proposed CST classification. In addition, a functional characterization of the metagenomic datasets revealed particular genetic features associated with each assigned vaginotype.

Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice

Around 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth.

The Microbiome and Preterm Birth: A Change in Paradigm with Profound Implications for Pathophysiologic Concepts and Novel Therapeutic Strategies

Preterm birth poses a global challenge with a continuously increasing disease burden during the last decades. Advances in understanding the etiopathogenesis did not lead to a reduction of prematurely born infants so far. A balanced development of the host microbiome in early life is key for the maturation of the immune system and many other physiological functions. With the tremendous progress in new diagnostic possibilities, the contribution of microbiota changes to preterm birth and the acute and long-term sequelae of prematurity have come into the research focus. This review summarizes the latest advances in the understanding of microbiomes in the amniotic cavity and the female lower genital tract and how changes in microbiota structures contribute to preterm delivery. The exhibition of these highly vulnerable infants to the hostile environment in the neonatal intensive care unit necessarily entails the rapid colonization with a nonbalanced microbiome in a situation where the organism is still very prone and at an early stage of development. The global research efforts to decipher pathologic changes will pave the way to new pre- and postnatal therapeutic concepts.

The Human Ureaplasma Species as Causative Agents of Chorioamnionitis

The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated with spontaneous abortions or miscarriages, neonatal respiratory diseases, and chorioamnionitis. Despite the fact that these microorganisms have been habitually found within placentae of pregnancies with chorioamnionitis, the role of Ureaplasma species as a causative agent has not been satisfactorily explained. There is also controversy surrounding their role in disease, particularly as not all women infected with Ureaplasma spp. develop chorioamnionitis. In this review, we provide evidence that Ureaplasma spp. are associated with diseases of pregnancy and discuss recent findings which demonstrate that Ureaplasma spp. are associated with chorioamnionitis, regardless of gestational age at the time of delivery. Here, we also discuss the proposed major virulence factors of Ureaplasma spp., with a focus on the multiple-banded antigen (MBA), which may facilitate modulation/alteration of the host immune response and potentially explain why only subpopulations of infected women experience adverse pregnancy outcomes. The information presented within this review confirms that Ureaplasma spp. are not simply "innocent bystanders" in disease and highlights that these microorganisms are an often underestimated pathogen of pregnancy.

The placental membrane microbiome is altered among subjects with spontaneous preterm birth with and without chorioamnionitis

BACKGROUND

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality and is not uncommonly associated with chorioamnionitis. We recently have demonstrated that the placenta harbors a unique microbiome with similar flora to the oral community. We also have shown an association of these placental microbiota with PTB, history of antenatal infection, and excess maternal weight gain. On the basis of these previous observations, we hypothesized that the placental membranes would retain a microbiome community that would vary in association with preterm birth and chorioamnionitis.

OBJECTIVE

In the current study, we aimed to examine the differences in the placental membrane microbiome in association with PTB in both the presence and absence of chorioamnionitis and/or funisitis using state-of-the-science whole-genome shotgun metagenomics.

STUDY DESIGN

This was a cross-sectional analysis with 6 nested spontaneous birth cohorts (n = 9-15 subjects/cohort): Term gestations without chorioamnionitis, term with chorioamnionitis, preterm without chorioamnionitis, preterm with mild chorioamnionitis, preterm with severe chorioamnionitis, and preterm with chorioamnionitis and funisitis. Histologic analysis was performed with Redline's criteria, and inflammatory cytokines were analyzed in the cord blood. DNA from placental membranes was extracted from sterile swabs collected at delivery, and whole-genome shotgun sequencing was performed on the Illumina HiSeq platform. Filtered microbial DNA sequences were annotated and analyzed with MG-RAST (ie, Metagenomic Rapid Annotations using Subsystems Technology) and R.

RESULTS

Subjects were assigned to cohorts on the basis of gestational age at delivery and independent scoring of histologic chorioamnionitis. We found that preterm subjects with severe chorioamnionitis and funisitis had increases in cord blood inflammatory cytokines. Of interest, although the placental membrane microbiome was altered in association with severity of histologic chorioamnionitis (permutational multivariate analysis of variance P = .005), there was no observable impact with either betamethasone or antibiotic treatment. In preterm subjects with chorioamnionitis, we found a high abundance of both urogenital and oral commensal bacteria. These alterations in the microbiome were accompanied by significant variation (P < .05) in microbial metabolic pathways important in the glucose-fed pentose phosphate pathway (term subjects), or glycerophopholipid metabolism, and the biosynthesis of the siderophore group nonribosomal peptides (preterm subjects).

CONCLUSION

Consistent with ours and others previous findings, women who experienced spontaneous PTB harbor placental microbiota that further differed by severity of chorioamnionitis. Integrative metagenomic analysis revealed significant variation in distinct bacterial metabolic pathways, which we speculate may contribute to risk of preterm birth with and without severe chorioamnionitis.

Infectious causes of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency among premature infants. Although a large body of research has focused on understanding its pathogenesis, the exact mechanism has not been elucidated. Of particular interest is the potential causative role of infectious culprits in the development of NEC. A variety of reports describe bacterial, viral, and fungal infections occurring in association with NEC; however, no single organism has emerged as being definitively involved in NEC pathogenesis. In this review, the authors summarize the literature on infectious causes of NEC.

The role of Mycoplasma and Ureaplasma in adverse pregnancy outcomes

Genital mycoplasmas are frequently found in the vaginal flora across socioeconomic and ethnic groups and have been demonstrated to be involved in adverse perinatal outcomes. Both Mycoplasma and Ureaplasma spp cause inflammation potentially leading to spontaneous preterm birth and PPROM as well as postdelivery infectious complications and neonatal infections. Herein we have provided an overview of the existing literature and supportive evidence for genital mycoplasma's role in perinatal complications. Future research will need to focus on clearly delineating the species, allowing for discrimination of their effects.

Placental features of chorioamnionitis colonized with Ureaplasma species in preterm delivery

Ureaplasma spp. is detected in the urogenital tract, including the vagina, cervix, chorioamnion, and placenta. Their colonization is associated with histologic chorioamnionitis (CAM), often observed in placentas from preterm delivery. We isolated Ureaplasma spp. from 63 preterm placentas among 151 specimens, which were delivered at <32 wk of gestation. Of the 63 placentas, 52 (83%) revealed CAM in cultures positive for Ureaplasma spp., however, CAM was observed only in 30% (26/88) of cultures negative for Ureaplasma spp. (p < 0.01). Colonization by Ureaplasma spp. was an independent risk factor for CAM (OR, 11.27; 95% CI, 5.09-24.98). Characteristic neutrophil infiltration was observed in the amnion and subchorion (bistratified pattern) in cultures positive for Ureaplasma spp. FISH analysis of CAM placenta with male infant pregnancy indicated that bistratified infiltrated neutrophils showed the XX karyotype and umbilical vein infiltrated neutrophils showed XY karyotype. The distribution of sulfoglycolipid, the receptor of Ureaplasma spp., was mainly detected in the amnion. Ureaplasmal urease D protein and ureB gene were both detected in the amnion, indicating direct colonization by Ureaplasma spp.

Effect of experimental genital mycoplasmosis on production of matrix metalloproteinases in membranes and amniotic fluid of Sprague-Dawley rats

Problem

Preterm, premature rupture of membranes (PPROM) is a dire pregnancy outcome that is frequently associated with infection by the genital mycoplasmas, Mycoplasma hominis, Ureaplasma parvum, and U. urealyticum. One potential mechanism by which these microorganisms may cause PPROM is by increasing the concentration of matrix metalloproteinases (MMPs) in the membranes and amniotic fluid. We tested this hypothesis in a well‐defined model system of genital infection with M. pulmonis, a natural reproductive pathogen of rats.

Method of study

Timed‐pregnant, specific pathogen‐free, Sprague–Dawley rats were infected with 10⁷ CFU M. pulmonis at gestation day (gd) 14. Controls received an equivalent volume (100 μL) of sterile medium. At gd 18, rats were euthanized, and membranes and amniotic fluids were harvested and stored at −70°C until analysis. Proteinase activity of amniotic fluid and membranes was resolved on discontinuous 7.5% sodium dodecyl sulfate–polyacrylamide gel electrophoresis gelatin zymography gels. Band intensity was determined using a digital gel documentation system and the manufacturer's software (Kodak).

Results

Gelatinolytic activity associated with a band similar in molecular weight to ProMMP‐9 (92 kDa, the inactive precursor of MMP‐9) was significantly increased in amniotic fluids and membranes harvested from M. pulmonis‐treated pups at gd 18 when compared with tissues harvested from control pups. Both ProMMP‐9 and ProMMP‐2 (72 kDa, the inactive precursor of MMP‐2) were increased in infected animals at gd 21.

Conclusion

Our study suggests that the genital mycoplasmas can increase MMP‐9 production in vivo.

Endotracheal colonization at birth is associated with a pathogen-dependent pro- and antiinflammatory cytokine response in ventilated preterm infants: a prospective cohort study

The possible association between mediators of inflammation such as cytokines and perinatal colonization of the respiratory tract remains unclear. This prospective cohort study evaluated endotracheal colonization in 141 ventilated preterm infants at birth. The relation with cytokine response in the airways and C-reactive protein (CRP) in umbilical blood was investigated. Of the 141 preterm infants enrolled in this study, 37 (26%) were colonized. In addition to traditional pathogens (61%), commensal species (26%) and Mycoplasmataceae (13%) were isolated. Both the pro-inflammatory cytokines IL-1 beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha as well as the antiinflammatory IL-10 are increased in colonized patients in a dose-dependent manner, with the strongest response in neonates colonized with Gram-negative organisms. There was no antimicrobial IL-12p70 response in colonized infants. Commensal flora is associated with the same inflammatory response as traditional pathogens. Although the umbilical cord blood CRP level was significantly higher in neonates with endotracheal colonization, it was highest in those colonized with Gram-negative organisms but still close to normal limits. Microorganisms in the endotracheal fluid of ventilated preterm infants are associated with a pathogen-specific and dose-dependent cytokine response in the airways and systemic CRP response.

Maternal genital colonization with Ureaplasma urealyticum promotes preterm delivery: association of the respiratory colonization of premature infants with chronic lung disease and increased mortality

BACKGROUND

Infection of the chorioamnion with Ureaplasma urealyticum has been associated with low birth weight. Respiratory tract colonization in preterm infants has been associated with the development of chronic lung disease (CLD). The purpose of the present study was to determine the frequency of colonization of the mother's vagina and the preterm infant's respiratory tract and to associate U. urealyticum with premature birth and with development of CLD in the newborn.

METHODS

The present prospective study involved 126 mothers with preterm delivery and 125 mothers with full-term delivery, as well as their offspring. Vaginal secretion specimens were obtained from each mother before delivery. Rhinopharyngeal secretion or tracheal lavage specimens were collected after the birth of each premature and full-term infant and then periodically during hospitalization.

RESULTS

Vaginal Ureaplasma colonization occurred among 36.5% of mothers with preterm delivery and among 38% of mothers with full-term delivery. The rate of vertical transmission was 33% and 17% for mothers with preterm delivery and mothers with full-term delivery, respectively. The transmission rate for infants, according to birth weight, was as follows: 60%, for infants with a birth weight of <1000 g; 50%, for infants with a birth weight of 1000-1500 g; and 15.3%, for infants with a birth weight of > or =1500 g (P=.001). The median gestational age of preterm infants born to colonized mothers was 28.5 weeks, and that of preterm infants born to noncolonized mothers was 32 weeks (P<.0001). The median birth weight of colonized preterm infants was 1135 g, and that of noncolonized infants was 1670 g (P<.0001). Twenty-four percent of preterm infants and 10% of full-term infants were colonized with U. urealyticum. Of colonized preterm infants, 27% developed CLD, compared with 9% of noncolonized infants (P=.03). Mortality was significantly higher among colonized preterm infants (P=.003).

CONCLUSIONS

The rate of vertical transmission is highest among preterm infants with a birth weight of <1500 g. Vaginal colonization with Ureaplasma organisms is associated with premature delivery. Colonization of the respiratory tract of infants is associated with the development of CLD and with increased mortality.

Histo-topographic distribution of acute inflammation of the human umbilical cord

Acute inflammation of the umbilical cord, acute funisitis, is a sign of fetal inflammatory response, and the clinicopathological need for its identification is increasing. This study was conducted in order to describe the topographic distribution of acute funisitis, and thereby to provide more information on the intrinsic nature of acute funisitis and find a better way of pathologically examining the umbilical cord. A total of 10 umbilical cords affected by acute funisitis were histopathologically examined throughout their entire lengths at 1 mm intervals. Pathological examination was done to characterize the extent of the funisitis, the involvement of the vein (phlebitis) or of one or both arteries (arteritis), and the presence of inflammation in Wharton's jelly. Umbilical cord plasma interleukin (IL)-6 was measured by specific immunoassay to assess whether or not the severity of acute funisitis correlates with fetal cytokine response. It would appear that the inflammatory reaction begins as a discrete, multifocal process which eventually becomes contiguous as the inflammatory reaction proceeds. Umbilical cord plasma IL-6 concentrations tended to correlate with the extent of umbilical cord inflammation. The initial phase of acute funisitis involves discrete and multiple foci along the length of the umbilical cord. Moreover, the extent of acute funisitis reflects the severity of systemic fetal cytokine response. Therefore, adequate sampling using multiple sections would facilitate the identification of acute funisitis. We propose a standard sampling procedure taking one section from each third of the umbilical cord.

The evaluation of infection and pulmonary maturity in women with premature rupture of the membranes

Although the etiology of PROM is multifactorial, increasing evidence regarding clinical risk factors, membrane histology, membrane culture, and amniotic fluid microbiology shows a strong association with infection. Recent studies suggest an association between genital tract infection, preterm labor (PTL), and preterm premature rupture of the membranes (pPROM). If correct, this information may be used to target areas for prevention, as well as to develop management protocols. This article reviews both the diagnostic tests for the causes associated with pPROM and the evaluation of intraamniotic infection and pulmonary maturity in patients with pPROM.

Ureaplasma urealyticum in a neonatal intensive care population

The incidence of Ureaplasma colonization at birth and its effect on the development of chronic lung disease (CLD) and on mortality was studied in a neonatal intensive care population. Ureaplasma colonization was associated with a birthweight < 1000 g (odds ratio [OR] 3.45 confidence intervals [CI] 2.13-5.60) and a gestational age < 30 weeks (OR 2.54 CI 1.71-3.79). In a case-controlled study of 112 infants, significant associations with Ureaplasma colonization were maternal pyrexia in labour (n = 38 vs 21; P = 0.015), the requirement for antibiotics in labour (n = 39 vs 16; P = 0.0005) and vaginal delivery (n = 78 vs 58; P = 0.009). Risk factors associated with the development of CLD were birthweight < 1000 g (OR 3.77 CI 2.53-5.62) and delivery by Caesarean section (OR 1.65 CI 1.11-2.43). Within the group delivered by Caesarean section. Ureaplasma colonization was also associated with an increased risk of CLD (OR 1.97 CI 1.08-3.62). Ureaplasma colonization of infants at birth is associated with factors suggestive of maternal chorioamnionitis as well as preterm birth and low birthweight. In infants delivered by Caesarean section, Ureaplasma colonization is associated with an increased risk of chronic lung disease.

The severity of fetal membrane infection and pregnancy complications

The purpose of this report is to examine the association of histologic chorioamnionitis with microorganisms isolated from the fetal membranes and to evaluate whether microorganisms with or without inflammation are associated with labor characteristics and with pregnancy complications. Inflammation was more common among membranes that yielded pathogenic bacteria (47%, P = 0.002) or Urea-plasma urealyticum (34%, P = 0.03) than among membranes that yielded no growth or nonpathogenic bacteria (20%). Prolonged membrane rupture (P = 0.0001), infant birth weight less than 2500 g (P = 0.02), and intraamniotic infection (P = 0.001) occurred more frequently among those women whose membranes yielded pathogenic bacteria than among those whose membranes yielded no growth or nonpathogenic bacteria. Our findings suggest that placental membranes in which pathogenic bacteria are accompanied by inflammation are associated with the highest risk of pregnancy complications.

Polymerase chain reaction-amplification of urease genes: rapid screening for ureaplasma urealyticum infection in endotracheal aspirates of ventilated newborns

Ureaplasma urealyticum infection has been considered to play an important role in the development of bronchopulmonary dysplasia (BPD) in premature infants. Since standard culture methods of U. urealyticum are difficult to perform, new rapid and sensitive methods are needed to detect lung infection of ventilated newborns. Here we describe the polymerase chain reaction as a rapid method to screen endotracheal aspirates for ureaplasma infection. Urease-specific sequences could only be detected in 1 out of 36 ventilated newborns. The procedure described in this paper may facilitate further studies to determine the role of U. urealyticum in development of BPD.

Microbiologic causes and neonatal outcomes associated with chorioamnion infection

Chorioamnion infection is associated with histologic chorioamnionitis and prematurity, but the specific chorioamnion microorganisms associated with histologic chorioamnionitis, prematurity, and poor neonatal outcome have not been identified. Bacteria were recovered from the chorioamnion cultures of 32% of 112 placentas delivered at less than or equal to 34 weeks' gestation and from 19% of 156 placentas delivered at greater than 34 weeks' gestation (odds ratio 2.1; 95% confidence interval 1.1 to 3.8). Chorioamnion bacteria most highly related to both prematurity and histologic chorioamnionitis were group B Streptococcus and Fusobacterium species. Chorioamnion infection with Peptostreptococcus was significantly related only to preterm delivery, and infection with Escherichia coli, Bacteroides, and Ureaplasma were significantly related to histologic chorioamnionitis. Among preterm infants, isolation of bacteria from the chorioamnion was related to an increased risk of neonatal death (rate ratio 3.8; 95% confidence interval 1.4 to 11.6). Bacterial infection of the chorioamnion is related to preterm birth, histologic chorioamnionitis, and neonatal death.

A randomized placebo-controlled trial of erythromycin for the treatment of Ureaplasma urealyticum to prevent premature delivery. The Vaginal Infections and Prematurity Study Group

Ureaplasma urealyticum has been associated with low birth weight and histologic chorioamnionitis and it is a frequent isolate from the chorioamnion of patients who are delivered prematurely. In prior clinical trials using antibiotics active against U. urealyticum, antibiotic treatment was associated with reduced prematurity and increased mean birth weight. In this multicenter, randomized, double-blind clinical trial, pregnant women with U. urealyticum were treated with 333 mg of erythromycin base or placebo three times daily, starting between 26 and 30 weeks' gestation and continuing through 35 completed weeks of pregnancy. Women with urinary tract infection or Neisseria gonorrhoeae infection were excluded from the trial, and women with Chlamydia trachomatis or group B streptococci were excluded from these analyses. Erythromycin did not eliminate U. urealyticum from the lower genital tract. There were no significant differences between erythromycin- and placebo-treated women in infant birth weight or gestational age at delivery, in frequency of premature rupture of membranes, or in neonatal outcome.

Antepartum cultures for Ureaplasma urealyticum are not useful in predicting pregnancy outcome. The Vaginal Infections and Prematurity Study Group

To test the hypothesis that genital colonization with Ureaplasma urealyticum would predict adverse pregnancy outcome, 4934 women from five medical centers were evaluated for vaginal colonization with U. urealyticum between 23 and 26 weeks' gestation and followed up to delivery. U. urealyticum colonization was associated with maternal age, parity, racial-ethnic group, martial status, income, education, smoking, number of sexual partners, and colonization with Trichomonas vaginalis, Mycoplasma hominis, and bacterial vaginosis. After adjustment for medical and sociodemographic factors in a multivariate analysis, there was no difference in the mean birth weight or proportion of low-birth-weight infants delivered by women who carried U. urealyticum and those who did not. U. urealyticum colonization at 23 to 26 weeks was not associated with preterm rupture of membranes, preterm labor, or preterm delivery. A positive vaginal culture for U. urealyticum in midgestation does not predict those women at risk for preterm labor, preterm delivery, preterm premature rupture of membranes, or delivery of a low-birth-weight infant.

Intra-uterine Candida infection: a report of four infected fetusses from two mothers

Although Candida albicans is a frequent inhabitant of the female genital tract, chorioamnionitis is rarely caused by this fungal organism. In this report we present two cases with manifest Candida chorioamnionitis. The first case is a twin pregnancy with premature delivery and survival of both twins. The second case is a pregnancy with intra-uterine contraceptive device in situ ending in a midtrimester abortion, followed by the next pregnancy also ending in an abortion in the second trimester. Possible triggers responsible for the increased invasiveness of otherwise benign Candida vaginitis are discussed. Foreign intra-uterine bodies such as contraceptive devices and cerclage sutures necessitate repetitive search for Candida species infection, and prompt adequate antifungal treatment in cases of documented infection. Both cases of the present report add further substantial evidence to the hypothesis of amniotic infection by ascending transcervical infection. The frequent concomitant cervical infections with other infectious agents as well as antibiotherapy influencing the normal Lactobacillary defence mechanisms are both likely to increase the risk. Systemic debilitating diseases that promote invasiveness are briefly discussed.

Mycoplasma hominis in maternal and fetal infections

Although prevalence of M. hominis colonization during pregnancy varies from 12-50%, its role in infections of the mother and newborn infants is unclear. Definite correlations exist with chorioamnionitis and amniotic fluid infections, but as it is rarely isolated alone during these infections, its pathogenic role is uncertain. Its association with septic abortion is similarly questioned. Prevalence and antibody titers to M. hominis increase with increasing parity. Transient bacteremia occurs in approximately 2.5% of normal deliveries. M. hominis does have a significant role in postpartum fever. Women harboring the organism during labor with low predelivery antibody titers are at risk. Approximately 30% of exposed infants are colonized (4% of all infants) but there are only a few reports of neonatal meningitis, pneumonia, or skin abscesses due to M. hominis. Most recover without specific therapy. The role of antimicrobial therapy of M. hominis in pregnancy and the neonatal period is unclear. Further studies of these issues should simultaneously consider all potential genital tract pathogens.

In vitro influence of Mycoplasma species on the stimulation of human polymorphonuclear granulocytes

The influence of Mycoplasma species (sp.) on the stimulation of human polymorphonuclear neutrophil granulocytes (PMNG) was determined by means of the luminol-dependent chemiluminescence (CL) method. When opsonized Mycoplasma sp. were used the CL response of PMNG was greater than in the presence of nonopsonized strains. Nonopsonized and nonspecifically opsonized Mycoplasma sp. showed a different CL response pattern. The stimulation of PMNG was with M. pneumoniae significantly weaker than with the other Mycoplasma sp. Using isolated M. hominis strains always the same CL-reaction of PMNG was observed. On the other hand, with 12 isolated U. urealyticum strains different results were obtained; 9 strains isolated from the upper urogenital tract lead to a slight PMNG stimulation comparable to that of M. pneumoniae. No correlation was found between CL response and bacterial killing. The weak stimulation of PMNG by M. pneumoniae and most of the U. urealyticum isolates suggest that this behaviour could be a factor of pathogenicity.

A case-control study of chorioamnionic infection and histologic chorioamnionitis in prematurity

To study the role of infection in prematurity, we studied the demographic and obstetrical characteristics, chorioamnionic cultures, and placental histologic features of women who delivered prematurely and compared these findings with those in women who delivered at term. Microorganisms were isolated from the area between the chorion and the amnion (chorioamnion) in 23 of 38 placentas (61 percent) from women with preterm labor who delivered before 37 weeks' gestation and in 12 (21 percent) of 56 placentas from women without preterm labor who delivered at term (odds ratio, 5.6; 95 percent confidence interval, 2.1 to 15.6). The most frequent isolates from the placentas of those whose infants were delivered prematurely were Ureaplasma urealyticum (47 percent) and Gardnerella vaginalis (26 percent). The recovery of any organism from the chorioamnion was strongly associated with histologic chorioamnionitis (odds ratio, 7.2; 95 percent confidence interval, 2.7 to 19.5) and with bacterial vaginosis (odds ratio, 3.2; 95 percent confidence interval, 1.1 to 6.6). When multiple logistic regression was used to control for demographic and obstetrical variables, premature delivery was still related to the recovery of organisms from the chorioamnion (odds ratio, 3.8; 95 percent confidence interval, 1.5 to 9.9) and with chorioamnionitis (odds ratio, 5.0; 95 percent confidence interval, 1.6 to 15.3). The proportion of placentas with evidence of infection was highest among those who delivered at the lowest gestational age. We conclude that infection of the chorioamnion is strongly related to histologic chorioamnionitis and may be a cause of premature birth.

Chorioamnionitis: its association with pregnancy outcome and microbial infection

In a study of 33 cases of perinatal death, chorioamnionitis was observed in 57.6% compared with 5% of 20 control cases (p less than 0.001) and in 70.8% of cases with no morphologic cause compared with 22.2% of cases with a defined cause of death (p less than 0.01). Chorioamnionitis was significantly associated with previous gestations (p less than 0.01), prolonged rupture of the membranes (p less than 0.001), prematurity (20 to 27 weeks' gestation) (p less than 0.001), and low birth weight (less than or equal to 1000 gm) (p less than 0.001) but not with elevated maternal white blood cell count or pyrexia. Overall, in patients with chorioamnionitis, the perinatal death rate was higher (p less than 0.01); more stillbirths occurred compared with early neonatal deaths (p less than 0.05), and there was a higher incidence of deaths with no defined cause (p less than 0.01) compared with cases without chorioamnionitis. Ureaplasma urealyticum or pathogenic bacteria were isolated more frequently from villous tissue of placentas from cases with chorioamnionitis (p less than 0.01) but not Mycoplasma hominis, Chlamydia trachomatis, or viruses. Furthermore, there was a higher prevalence of both elevated fetal antibody titer to U. urealyticum (p less than 0.025) and fetal titer fourfold above maternal titers (p less than 0.05) in cases with chorioamnionitis. The antibody responses and presence of microorganisms suggest that chorioamnionitis is associated with intrauterine infection and an associated increase in perinatal morbidity and mortality.

Screening for Ureaplasma urealyticum infections in the neonate and the association with prematurity

Ureaplasma urealyticum has been implicated in gynaecological, obstetrical and neonatal pathology. Increased levels of C-reactive protein and total IgM concentrations in cord blood have often been used as a screening method for infectious disease in the fetus and the newborn. Analysis of the isolation rate of U. urealyticum in function of the concentrations of these two parameters in cord blood showed that U. urealyticum was significantly (P less than 0.05) more frequently isolated when CRP was above normal in cord blood. No correlation between the IgM level in the newborn and the presence of U. urealyticum could be established. A significant relationship was found (P less than 0.01) between Ureaplasma isolation in the urine of mother and child on the one hand and gestational age on the other hand, which supports the hypothesis that U. urealyticum may play a role in preterm delivery.

Prevalence of six sexually transmitted disease agents among pregnant inner-city adolescents and pregnancy outcome

115 pregnant girls aged 13-17 years were investigated during the third trimester for endocervical infection with six sexually transmissible microorganisms. Specimens from 21 patients destroyed the tissue cell monolayers for propagation of Chlamydia trachomatis, but 11 were no longer toxic when recultured after freezing or with additional antimicrobial agents; Trichomonas vaginalis was present in 76% of the toxic specimens. C trachomatis was recovered from 37% of 105 specimens. T vaginalis was recovered from 34% of the 115 subjects, candida from 38%, Mycoplasma hominis from 70%, and Ureaplasma urealyticum from 90%. Neisseria gonorrhoeae was cultured from 1 of 12 girls infected earlier in pregnancy. T vaginalis infection, alone or with C trachomatis or candida, was associated with low gestational age and low birthweight. C trachomatis and candida infections alone had no effect on pregnancy outcome.

Association of Ureaplasma urealyticum in the placenta with perinatal morbidity and mortality

We investigated the presence of ureaplasmas, mycoplasmas, chlamydiae, fungi, aerobic and anaerobic bacteria, and cytomegalovirus in fetal membranes and evaluated their association with perinatal morbidity and mortality. We cultured 801 placentas from three groups of subjects (144 who died in the perinatal period, 452 neonates admitted to the intensive-care unit, and 205 controls). Ureaplasma urealyticum, Mycoplasma hominis, or both were isolated from 21 per cent of placentas of premature and term infants who died in the perinatal period, 25 per cent of those admitted to intensive care, and 11 per cent of controls. Gestational age and birth weight were inversely related to isolation of ureaplasma, and chorioamnionitis was positively related to isolation. The presence of ureaplasmas in the placenta suggests the transcervical migration of these microorganisms from the lower genitourinary tract. These data show a strong association between ureaplasma infection of the placenta and low birth weight of the neonate and suggest that the association is causal.

A prospective study of chlamydial, mycoplasmal, and viral infections in a neonatal intensive care unit

In a prospective study of non-bacterial infection in a neonatal intensive care unit in north west London, Chlamydia trachomatis infection was identified in 4 of 280 babies (1.4%) and was the most common cause of neonatal ophthalmia. One of the four developed pneumonitis. Ureaplasma urealyticum was found to colonise the nasopharynx in 53 of 235 babies (22.6%), with Mycoplasma hominis present in 6 of 235 babies (2.6%). There was a statistically significant association between U urealyticum colonisation and preterm birth or prolonged rupture of membranes. Colonisation occurred more commonly in babies with apnoea. Viral infection was detected in 16 of 280 babies (5.7%). Rotavirus was identified in 5 of 170 babies (2.9%) and was associated with necrotising enterocolitis in two infants and with bloody diarrhoea in another. Respiratory syncytial virus, which was identified in 4 of 280 babies (1.4%), was not associated with lower respiratory tract infection.

Isolation of mycoplasmas and bacteria from the blood of postpartum women

Mycoplasmas and/or bacteria were recovered from the blood cultures of 26 (20.8%) of 125 febrile postpartum women. Genital mycoplasmas were recovered from 16 (12.8%) of the 125 febrile women and from none of 60 afebrile postpartum women (p less than 0.005). The presence of mycoplasmaemia was associated with a young age, primigravidity, and nulliparity. The isolation of organisms from the blood was also associated with fever during labor, internal monitor use, and a cesarean delivery.

The effect of genital mycoplasmas on human fetal growth

The relation between maternal genital colonization by mycoplasmas and fetal growth was examined in a study of 195 women. Swabs were taken from the endocervix on three occasions during pregnancy and once post partum. Ureaplasma urealyticum organisms (ureaplasmas) were recovered from 42.7 per cent of Caucasian women and from 34.6 per cent of Asian women at their first antenatal visit. These isolation rates remained similar throughout pregnancy, although there was a decrease in isolation after delivery. Mycoplasma hominis was recovered from 6.5 per cent of Caucasians and from 11.5 per cent of Asians at their first antenatal visit and these rates remained fairly constant during pregnancy and after delivery. Caucasian women colonized by ureaplasmas had a longer mean length of gestation (p less than 0.025) than non-colonized women. Furthermore, the colonized women gave birth to infants who had a statistically significant greater mean birth weight and a greater mean birth weight-for-dates than those of the non-colonized Caucasians. There was no correlation between gestational length, birth weight, or birth weight-for-dates and genital colonization of Asian mothers by ureaplasmas or M. hominis. It is clear the ureaplasmas are not associated with low birth weight in our population.

Unconventional bacteria in urinary tract disease: Ureaplasma urealyticum

Bladder-aspirate urine samples (N = 428) were cultured for the presence of fastidious microorganisms. These samples were obtained from 190 patients with urinary tract disease or symptoms suggesting infection of the urinary tract in whom standard bacteriologic investigation had failed to indicate bacterial infection. Ureaplasma urealyticum was recovered alone or in association with other microorganisms from the bladder urine of 75% of patients with reflux scarring and abnormal renal function. Ureaplasma organisms were localized to the upper urinary tract in 80% of patients with bladder counts greater than 10(3) colony-forming units per ml. The results indicate that microorganisms not conventionally associated with urinary tract infection are recoverable from the bladder urine of a high percentage of patients with so-called "sterile pyelonephritis," in which group of patients these microorganisms may contribute to progressive renal disease.

Ureaplasma urealyticum (T-mycoplasma) in vaginal fluid and cervical mucus from fertile and infertile women

Ureaplasma urealyticum (T-mycoplasma) was isolated more frequently and in heavier growth from cervical mucus (49%) than from vaginal fluid (34%). It was isolated in 24% of vaginal fluid samples and in 35% of cervical mucus samples from fertile women, and in 29% of vaginal fluid samples and in 47% of cervical mucus samples from infertile women. The incidence of infection was high following abortion or total hysterectomy and during pregnancy or oral contraceptive use. T-mycoplasma was also isolated from the vaginal fluid and cervical mucus of a woman with tubo-ovarian abscess, but was not present in women with Trichomonas vaginalis infection. U. urealyticum did not alter the physiophysiologic characteristics of vaginal fluid and cervical mucus or the sperm penetration and sperm viability in cervical mucus. Treatment with tetracycline eradicated the organism in 88% of the infected women. Pregnancies were recorded during a 6-month follow-up in 1 of 19 infertile women who were treated with tetracycline.

Amniotic fluid infections in an African city

Amniotic fluid infections were the most common cause of perinatal death in Addis Ababa, Ethiopia (21.8/1,000 live births). Most such infections appear to originate in the fetal membranes near the cervical os. The high rate of spread of these local infections into the amniotic fluid in Addis Ababa appears related to a lack of antimicrobial activity in amniotic fluids. Factors that adversely affected nutrition in the gravid woman, lack of prenatal medical care, and low water usage were associated with the high rate of fatal infections.

Mycoplasma T strains and perinatal death

In 23 out of 290 perinatal deaths in Addis Ababa, mycoplasma T strains were the only organisms responsible for congenital pneumonia and death. All but 2 of the infants were stillborn, 16 dying during the last six weeks of gestation. Infections apparently occurred through intact fetal membranes.