Study on the usefulness of APR scores from the viewpoint of proinflammatory cytokines

Intrauterine Inflammation, Excessive Fetal Growth and Respiratory Morbidities in Moderate-To-Late Preterm Neonates

INTRODUCTION

Respiratory morbidities in neonates are often progressive and life-threatening, and its early prediction is crucial. Intrauterine inflammation is one of the key control variables of respiratory morbidities in both very preterm and term neonates; however, little is known about its effects in the remaining group of moderate-to-late preterm neonates born between 32+0 and 36+6 weeks of gestation. This study aimed to confirm whether intrauterine inflammation is associated with respiratory morbidities in moderate-to-late preterm neonates.

METHODS

A single-center retrospective observational study was conducted in neonates born between 32+0 and 34+6 weeks of gestation between April 2013 and March 2018. The correlation between respiratory morbidities (defined as a requirement for invasive mechanical ventilation longer than the median duration of 3 days) and intrauterine inflammation was assessed using multivariable logistic regression analysis.

RESULTS

The study population comprised 242 neonates born at 33.7 ± 0.8 weeks of gestation and weighing 1,936 ± 381 g. The multivariable model to predict the outcome comprised respiratory distress syndrome (odds ratio [OR]: 9.1; 95% confidence interval [CI]: 3.7-22.5; p < 0.001), lower gestational age (per week; OR: 0.5; 95% CI: 0.3-0.8; p < 0.005), higher birth-weight z-score (OR: 1.6; 95% CI: 1.2-2.2; p < 0.005), lower cord blood pH (per 0.10; OR: 0.5; 95% CI: 0.3-0.7; p < 0.005), and chorioamnionitis (OR: 2.8; 95% CI: 1.1-7.2; p < 0.05).

CONCLUSION

Together with the incidence of respiratory distress syndrome and gestational age, chorioamnionitis and high birth-weight z-scores were associated with an increased incidence of respiratory morbidities in moderate-to-late preterm neonates. The deleterious impact of intrauterine inflammation on the lungs may be common in neonates of virtually all gestational ages. Traditional admission policy of neonatal intensive care units based on a threshold birth-weight, may leave a group of neonates without close observation despite their increased risks for respiratory morbidities.

Evidence of both foetal inflammation and hypoxia-ischaemia is associated with meconium aspiration syndrome

Foetal hypoxia–ischaemia is a key trigger of meconium aspiration syndrome (MAS). However, many neonates develop MAS without evidence of hypoxia–ischaemia, suggesting the presence of covert but important risk variables. We evaluated the association of MAS with clinical variables, placental histopathologic findings, and inflammatory biomarkers at birth. Of 1336 symptomatic and asymptomatic term singleton neonates with meconium-stained amniotic fluid, 88 neonates (6.6%) developed MAS. Univariate analysis showed that MAS development was associated with low 1- and 5-min Apgar scores, low cord blood pH, funisitis, higher α₁-acid glycoprotein levels, and higher haptoglobin levels (all p < 0.001 except for p = 0.001 for haptoglobin). Associations of MAS with caesarean delivery (p = 0.004), premature rupture of the membranes (p = 0.006), chorioamnionitis (p = 0.007), and higher C-reactive protein levels (p = 0.008) were lost when adjusted for multiple comparisons. The final multivariate model to explain MAS development comprised lower cord blood pH (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.47–0.73; p < 0.001), funisitis (OR 2.45; 95% Cl 1.41–4.26; p = 0.002), and higher α₁-acid glycoprotein levels (OR 1.02; 95% Cl 1.01–1.03; p = 0.001). Our data from a large cohort of neonates suggested that intrauterine inflammation is one of the key independent variables of MAS development, together with foetal hypoxia–ischaemia.

Influence of foetal inflammation on the development of meconium aspiration syndrome in term neonates with meconium-stained amniotic fluid

Background

Meconium-stained amniotic fluid is observed in approximately 10–15% of all deliveries; however, only 5% of neonates with meconium-stained amniotic fluid develop meconium aspiration syndrome (MAS). Although foetal distress and subsequent sympathetic stimulation have been considered as the primary upstream events of MAS, this clinical complication sometimes occurs due to other pathologies, such as intraamniotic inflammation. The aim of this study was to investigate whether the incidence of MAS is associated with the presence of funisitis and chorioamnionitis in term neonates with meconium-stained amniotic fluid.

Methods

Between April 2013 and March 2015, a total of 95 term neonates with meconium-stained amniotic fluid, who were hospitalized at a neonatal intensive care unit, were enrolled in the study. The placenta and umbilical cord were histopathologically examined. Clinical variables and histopathological findings associated with the incidence of MAS were studied.

Results

A total of 36 neonates developed MAS. Univariate logistic regression analysis revealed that a heavier birth weight, male sex, 1-min Apgar score ≤ 7, funisitis (but not chorioamnionitis), and elevated acute-phase inflammatory reaction score were associated with increased incidence of MAS (all p < 0.05). The multivariate model comprised funisitis (OR = 5.03, 95% CI [1.63–15.5], 1-min Apgar score ≤ 7 (OR = 2.74, 95% CI [1.06–7.09], and male sex (OR = 3.4, 95% CI [1.24–9.34].

Conclusion

In neonates with meconium-stained amniotic fluid, funisitis, as well as low 1-min Apgar score and male sex, was identified as an independent variable for MAS development. Intraamniotic inflammation might be involved in the pathological mechanisms of MAS.