Association of development of chronic lung disease of newborns with neonatal colonization of Ureaplasma and cord blood interleukin-8 level

Intra-Amniotic Infection with Ureaplasma parvum Causes Preterm Birth and Neonatal Mortality That Are Prevented by Treatment with Clarithromycin

Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. Multiple etiologies are associated with preterm birth; however, 25% of preterm infants are born to a mother with intra-amniotic infection, most commonly due to invasion of the amniotic cavity by Ureaplasma species. Much research has focused on establishing a link between Ureaplasma species and adverse pregnancy/neonatal outcomes; however, little is known about the taxonomy of and host response against Ureaplasma species. Here, we applied a multifaceted approach, including human samples, in vivo models, and in vitro manipulations, to study the maternal-fetal immunobiology of Ureaplasma infection during pregnancy. Furthermore, we investigated the use of clarithromycin as a treatment for this infection. Our research provides translational knowledge that bolsters scientific understanding of Ureaplasma species as a cause of adverse pregnancy/neonatal outcomes and gives strong evidence for the use of clarithromycin as the recommended treatment for women intra-amniotically infected with Ureaplasma species.

Intra-amniotic infection is strongly associated with adverse pregnancy and neonatal outcomes. Most intra-amniotic infections are due to Ureaplasma species; however, the pathogenic potency of these genital mycoplasmas to induce preterm birth is still controversial. Here, we first laid out a taxonomic characterization of Ureaplasma isolates from women with intra-amniotic infection, which revealed that Ureaplasma parvum is the most common bacterium found in this clinical condition. Next, using animal models, we provided a causal link between intra-amniotic inoculation with Ureaplasma species and preterm birth. Importantly, the intra-amniotic inoculation of Ureaplasma species induced high rates of mortality in both preterm and term neonates. The in vivo potency of U. parvum to induce preterm birth was not associated with known virulence factors. However, term-derived and preterm-derived U. parvum isolates were capable of inducing an intra-amniotic inflammatory response. Both U. parvum isolates invaded several fetal tissues, primarily the fetal lung, and caused fetal inflammatory response syndrome. This bacterium was also detected in the placenta, reproductive tissues, and most severely in the fetal membranes, inducing a local inflammatory response that was replicated in an in vitro model. Importantly, treatment with clarithromycin, a recently recommended yet not widely utilized antibiotic, prevented the adverse pregnancy and neonatal outcomes induced by U. parvum. These findings shed light on the maternal-fetal immunobiology of intra-amniotic infection.

Vaginal Ureaplasma species increase chorioamnionitis in very preterm infants with preterm premature rupture of the membranes at < 28 weeks of gestation

Our aim was to investigate the association between vaginal Ureaplasma species (spp.) and the subsequent occurrence of chorioamnionitis (CAM), perinatal death, neonatal morbidity, and long-term neurodevelopmental impairments (NDIs) at 3 years of age. We analyzed 55 pregnant women with singleton pregnancy who had preterm premature rupture of the membranes (pPROM) at < 28⁺⁰ weeks of gestation, and delivered between 22⁺⁰ and 31⁺⁶ weeks at our tertiary hospital in 2007-2016. NDIs were defined as either cerebral palsy or developmental delay evaluated at 1.5 and/or 3 years old. The presence of Ureaplasma spp. and Mycoplasma hominis were evaluated using urea-arginine broth and Mycoplasma PPLO Agar. The presence of Ureaplasma spp. in the vagina was positive in 41%. Vaginal Ureaplasma spp. was a significant risk factor for CAM; however, it was not significantly associated with the occurrence of perinatal death, pulmonary hypoplasia, respiratory distress syndrome, transient tachypnea of the newborn, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia defined as oxygen required and occasional ventilatory assistance required at week 36 as modified (BPD₃₆), or NDIs. The crude odds ratio (95% confidence interval) of Ureaplasma spp. for the occurrence of CAM was 9.5 (1.10-82) (p = 0.041). In very preterm birth infants with pPROM, CAM, BPD₃₆, and NDIs occurred in 78, 60, and 36%, respectively. Vaginal Ureaplasma spp. was a significant risk factor for CAM in very preterm birth infants with pPROM. The incidences of BPD₃₆ and NDIs in such infants were very high, nearing 3/5 and 1/3, respectively.

Association between pulmonary ureaplasma colonization and bronchopulmonary dysplasia in preterm infants: updated systematic review and meta-analysis

BACKGROUND

Previous meta-analyses have reported a significant association between pulmonary colonization with Ureaplasma and development of bronchopulmonary dysplasia (BPD). However, because few studies reporting oxygen dependency at 36 weeks corrected gestation were previously available, we updated the systematic review and meta-analyses to evaluate the association between presence of pulmonary Ureaplasma and development of BPD.

METHODS

Five databases were searched for articles reporting the incidence of BPD at 36 weeks postmenstrual age (BPD36) and/or BPD at 28 days of life (BPD28) in Ureaplasma colonized and noncolonized groups. Pooled estimates were produced using random effects meta-analysis. Meta-regression was used to assess the influence of difference in gestational age between the Ureaplasma-positive and Ureaplasma-negative groups. The effects of potential sources of heterogeneity were also investigated.

RESULTS

Of 39 studies included, 8 reported BPD36, 22 reported BPD28 and 9 reported both. The quality of studies was assessed as moderate to good. There was a significant association between Ureaplasma and development of BPD36 (odds ratio = 2.22; 95% confidence intervals: 1.42-3.47) and BPD28 (odds ratio = 3.04; 95% confidence intervals: 2.41-3.83). Sample size influenced the odds ratio, but no significant association was noted between BPD28 rates and difference in gestational age between Ureaplasma colonized and noncolonized infants (P = 0.96).

CONCLUSIONS

Pulmonary colonization with Ureaplasma continues to be significantly associated with development of BPD in preterm infants at both 36 weeks postmenstrual age and at 28 days of life. This association at BPD28 persists regardless of difference in gestational age.