Association of miR-182 expression in amniotic fluid with intrauterine infection and brain injury in premature infants

Changes of micro-ribonucleic acid-182 (miR-182) level in cases of intrauterine infection were investigated to explore the association between miR-182 level change and brain injury in premature infants. A total of 257 preterm infants born in obstetrics department of Jinan Maternity and Child Care Hospital from February 2015 to February 2017 were enrolled in this study. These preterm infants were divided into infected group (n=113) and uninfected group (n=144) based on pathological diagnosis results. Quantitative polymerase chain reaction (qPCR) was employed to detect miR-182 level in amniotic fluid. Bregmatic sagittal and coronal plus lateral fontanel craniocerebral ultrasound, craniocerebral computed tomography (CT) and craniocerebral magnetic resonance imaging examinations were conducted in these preterm infants within one week after birth, and the results were recorded. The relationship between intrauterine infection and brain injury in premature infants was analyzed, and the association of miR-182 level with brain injury was explored. According to pathological diagnoses, brain injury was found in 61 of 113 infants in the infected group, with an incidence rate of 54.0%; and 28 of 144 infants in uninfected group, with an incidence rate of 19.4%; among them, 3 had placental infection caused by intrauterine infection in pregnant women, and all preterm infants had brain damage. Risk value of brain injury in premature infants due to intrauterine infection was hazard ratio (HR) = 2.2611, χ(2)=33.798, P<0.02. Infected group had a higher miR-182 level in comparison with uninfected group, and the difference in miR-182 level between infected group and uninfected group was statistically significant (P<0.05). Intrauterine infection can lead to an increase in miR-182 level; growth in miR-182 level is closely related to brain injury in premature infants.