Effect of chorioamnionitis on brain development and injury in premature newborns

Infections in Pregnancy

Infections during pregnancy may affect a developing fetus. If left untreated, these infections can lead to the death of the mother, fetus, or neonate and other adverse sequelae. There are many factors that impact infection during pregnancy, such as the immune system changes during pregnancy, hormonal flux, stress, and the microbiome. We review some of the outcomes of infection during pregnancy, such as preterm birth, chorioamnionitis, meningitis, hydrocephaly, developmental delays, microcephaly, and sepsis. Transmission routes are discussed regarding how a pregnant woman may pass her infection to her fetus. This is followed by examples of infection during pregnancy: bacterial, viral, parasitic, and fungal infections. There are many known organisms that are capable of producing similar congenital defects during pregnancy; however, whether these infections share common mechanisms of action is yet to be determined. To protect the health of pregnant women and their offspring, additional research is needed to understand how these intrauterine infections adversely affect pregnancies and/or neonates in order to develop prevention strategies and treatments.

Mouse model of intrauterine inflammation: sex-specific differences in long-term neurologic and immune sequelae

Preterm infants, especially those that are exposed to prenatal intrauterine infection or inflammation, are at a major risk for adverse neurological outcomes, including cognitive, motor and behavioral disabilities. We have previously shown in a mouse model that there is an acute fetal brain insult associated with intrauterine inflammation. The objectives of this study were: (1) to elucidate long-term (into adolescence and adulthood) neurological outcomes by assessing neurobehavioral development, MRI, immunohistochemistry and flow cytometry of cells of immune origin and (2) to determine whether there are any sex-specific differences in brain development associated with intrauterine inflammation. Our results have shown that prenatal exposure appeared to lead to changes in MRI and behavior patterns throughout the neonatal period and during adulthood. Furthermore, we observed chronic brain inflammation in the offspring, with persistence of microglial activation and increased numbers of macrophages in the brain, ultimately resulting in neuronal loss. Moreover, our study highlights the sex-specific differences in long-term sequelae. This study, while extending the growing literature of adverse neurologic outcomes following exposure to inflammation during early development, presents novel findings in the context of intrauterine inflammation.

Severity of chorioamnionitis and neonatal outcome

AIM

The aim of this study is to elucidate whether the stage of chorioamnionitis is or is not associated with the development of neonatal diseases.

MATERIAL & METHODS

We reviewed the neonatal intensive care unit discharge files and placental pathology reports of 302 preterm infants. The presence of various stages of chorioamnionitis as well as absence of an association with chorioamnionitis (non-chorioamnionitis) were compared among neonatal diseases.

RESULTS

Preterm infants were grouped according to three stages of chorioamnionitis or the absence of an association with chorioamnionitis. Gestational age differed significantly between these groups. Before controlling for gestational age, the chorioamnionitis stage was significantly higher among infants with chronic lung disease, retinopathy of prematurity and intraventricular hemorrhage than in infants without these diseases. On the other hand, the chorioamnionitis stage was lower in infants with respiratory distress syndrome than without. After controlling for gestational age, the stage of chorioamnionitis was significantly lower in infants with respiratory distress syndrome than in infants without respiratory distress syndrome, whereas, significant differences were not detected between the presence and absence of chronic lung disease, retinopathy of prematurity and intraventricular hemorrhage. Furthermore, gestational age was a significant risk factor for chronic lung disease, respiratory distress syndrome, retinopathy of prematurity and intraventricular hemorrhage.

CONCLUSIONS

We found no significant differences in stages of chorioamnionitis between infants with and without neonatal diseases except for respiratory distress syndrome. A significant inverse relationship was observed between the stage of chorioamnionitis and development of respiratory distress syndrome.