Research on the Incidence Rate of Extremely Preterm Birth in China and Relationship between Extremely Preterm Birth and Chorioamnionitis

Abstract

To investigate the relationship between the extremely preterm birth and chorioamnionitis based on Chinese population. Retrospective analysis was performed to evaluate 164 cases hospitalized in Fujian Provincial Maternity and Children’s Hospital during 1st January 2017 and 31th June 2018. The clinical symptoms of the participators were recorded and the laboratory tests were performed. The incidence of the extremely preterm birth was 0.7 % accounting for 7.2 % in the total premature birth. The positive rate of the extremely preterm birth related with chorioamnionitis was 72 % and the positive rates in clinic and histological chorioamnionitis were 5.5 % and 66.5 %, which were significantly higher than those in early preterm birth, moderate preterm birth and late preterm birth. Histologic chorioamnionitis cases have no clinical symptoms. The positive rates of increased white blood cells count, neutrophils count and increased level of C-reactive protein in histological chorioamnionitis are 37.6 %, 39.4 %, 64.2 % and 0 % respectively, which are significantly lower than those in clinic chorioamnionitis (88.9 %, 100 %, 100 %, 11.1 %, respectively, p<0.05). The top three pathogens are ureaplasma urealytium, escherichia coli and group B streptococcus. 90.9 % of the extremely preterm born have severe neonatal complications; 63.6 % have septicemia and shared chorioamnionitis with the mother. Chorioamnionitis is an important risk factor of extremely preterm birth. The positive rate of the extremely preterm birth with chorioamnionitis is significantly higher than that early, modulate and late preterm birth. Histologic chorioamnionitis is the main type of chorioamnionitis, which may induce poor prognosis of the extremely preterm birth newbornsy.