Management and prognosis of extremely preterm infants with gestational age ≤25+6 weeks / 中华儿科杂志

Objective: To investigate the outcomes including major complications and prognosis of extremely preterm infants with gestational age ≤25+6 weeks. Methods: The cross-sectional study enrolled 233 extremely preterm infants with gestational age ≤25+6 weeks who were admitted to the Department of Neonatology of Shenzhen Maternity and Child Healthcare Hospital from January 2015 to December 2021. The clinical data including perinatal factors, treatments, complications, and prognosis were extracted and analyzed. These extremely preterm infants were also grouped according to gestational age and year of admission to further analyze their survival rate, major complications, causes of death, and long-term outcomes. The comparisons between the groups were performed with Chi-square test and Kruskal-Wallis. Results: Among these 233 extremely preterm infants, 134 (57.5%) were males and 99 (42.5%) females. The gestational age was (24.6±0.9) weeks, the birth weight was 710.0 (605.0,784.5) g, and the overall survival rate was 61.8% (144/233). Among the surviving extremely preterm infants, the earliest gestational age was 22+2 weeks and the lowest birth weight was 390 g. There were 17.6% (41/233) of extremely preterm infants had treatment withdrawn and were discharged in line with the will of guardians. Among the rest 192 extremely preterm infants managed with aggressive treatments, 14 (7.3%) died in hospital and 34 (17.7%) had treatment withdrawn later due to severe complications. Of the 192 extremely preterm infants, 144 (75.0%) survived, and the survival rate increased year by year (χ2=26.28, P<0.001) while the mortality decreased year by year (χ2=14.09, P=0.027). Among the survivors, 20.8%(30/144) had no major complications, and the incidence of complications was also negatively related with the gestational age (χ2=7.24, P=0.044), and the length of invasive ventilation was negatively related to the gestational age (χ2=29.14, P<0.001). In the group of less than 23+6 weeks, all extremely preterm infants had one or more major complications. The follow-up were completed in 122 infants and revealed that delayed motor development, language retardation, and hearing and vision impairment accounted for 17.2% (21/122), 8.2% (10/122) and 17.2% (21/122), respectively. Conclusions: Extremely preterm infants with gestational age ≤25+6 weeks are difficult to treat, but the survival rate of infants undergoing aggressive treatments increases year by year. Although the prevalence of major complications is still high, most extremely preterm infants have acceptable prognosis during follow-up.

Determination of Serum Unbound Bilirubin and Its Clinical Application Value in Neonates / 中山大学学报(医学科学版)

ObjectiveTo investigate the clinical appropriateness and application value of the peroxidase （POD） method for the detection of unbound bilirubin （UB） in neonatal serum. MethodsHydrogen peroxide （0.33 mol/L） and three different final concentrations （0.019， 0.038， 0.075 μg/mL） of horseradish peroxidase （HRP） were added to standard bilirubin solution （1， 2， 3 μmol/L） to obtain a standardized HRP primary rate constant Kp. Then 25 μL of neonatal serum was diluted by 41.6 fold， and measured with 2.4 and 4.8 μg/mL HRP at 37 ℃ under the dark， to determine the UB concentration. The accuracy， precision， and stability of the methodology were validated. The clinical characteristics of 33 jaundiced neonates were collected， including total serum bilirubin （TSB）， indirect bilirubin （IDB）， albumin （ALB）， bilirubin to albumin molar ratio （BAMR）， etc. The experimental data were analyzed by Graphpad Prism 8.0. ResultsA standardized Kp of （7.20±1.08） mL·μg-1·min-1 was determined at pH 7.4±0.2， 37 ℃ in the dark. The HRP activity and UB concentrations remained stable at -20 ℃ for 3 weeks and a week， respectively. The mean intra-day and inter-day coefficients of variation of the serum samples with different UB concentrations were less than 10%. In this study， the UB concentrations in 33 jaundiced neonates （gestational age ≥35 weeks） were measured by the POD method in the range of （0.32～1.20） μg/dL， which was positively correlated with TSB， IDB and BAMR. Of the five infants whose UB concentrations measured more than 1 μg/dL， three received intensive phototherapy （60%）. ConclusionsThe POD method combined with a standard equipment spectrophotometer to detect serum UB concentrations in neonates is easy to operate， rapid to detect， and low cost. This method has good accuracy and precision， which is convenient for clinical implementation. Moreover， the measurement of serum UB may assist us in better management of neonatal jaundice in clinical practice.