Short-time mortality and severe complications of very premature infants-a multicenter retrospective cohort study from Jiangsu Province during 2019-2021

Background: The short-term and long-term severe complications of preterm infants have brought serious psychological and economic burdens to the society and family. Therefore, our study aimed to investigate the risk factors for the mortality and serious complications in very premature infants less than 32 weeks of gestational age (GA), so as to guide the antenatal and postnatal care of very premature.

Methods: The very premature infants from 1 January 2019 to 31 December 2021 from 15 member hospitals of the Neonatal Intensive Care Unit (NICU) Multi-center Clinical Research Collaboration Group in Jiangsu Province were recruited. In accordance with the plan of the intensive care unit for unified management, recruitment of premature infants is carried out on the day of admission, and discharge or death is the outcome indicator in 1-2 months by telephone follow-up. The research content mainly includes three aspects: clinical information of mother and infant, outcomes and complications. According to the final outcomes, very premature infants were divided into two categories: survival without severe complications, survival with severe complications and death. Then, univariate and multivariate logistic regression model and receiver operating characteristic (ROC) analyses were used to analyze the independent risk factors.

Results: A total of 3,200 very premature infants with GA less than 32 weeks were recruited. The median GA is 30.00 (28.57, 31.14) weeks, the average birth weight is 1,350 (1,110, 1,590) g, among whom 375 premature infants survived with severe complications, and 2,391 premature infants survived without severe complications. Then, it was found that GA at birth was a protective factor for death and severe complications, whereas severe neonatal asphyxia and persistent pulmonary hypertension of the newborn (PPHN) were independent risk factors for death and severe complications in very premature infants born at less than 32 weeks of gestation.

Conclusions: The prognosis of very premature infants in NICU treatment depends not only on GA, but also on various perinatal factors and their clinical management, such as preterm asphyxia and PPHN occurrence, so the next step is necessary for multicenter continuous quality improvement to improve outcomes in very preterm infants.