The effects of antenatal corticosteroids therapy on very preterm infants after chorioamnionitis

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

Histological chorioamnionitis, antenatal steroids, and neonatal outcomes in very low birth weight infants: A nationwide study

Background

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs).

Methods

This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS.

Results

The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019).

Conclusions

We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

The Associations between Antenatal Corticosteroids and In-Hospital Outcomes of Preterm Singleton Appropriate for Gestational Age Neonates according to the Presence of Maternal Histologic Chorioamnionitis

INTRODUCTION

This study aimed to assess the association between antenatal corticosteroid (ACS) and in-hospital outcomes of preterm singleton appropriate for gestational age (AGA) infants according to the presence of maternal histologic chorioamnionitis (HCA).

METHODS

A retrospective study was performed with singleton AGA neonates of 23+0 to 33+6 weeks' gestation born between 2007 and 2014. We compared the clinical outcomes according to the presence of HCA and ACS use. We also divided the ACS group into 2 groups: infants who received ACS 2-7 days before birth (optimal ACS) or not (suboptimal ACS). Multivariate logistic regression with Firth's penalized likelihood was performed.

RESULTS

In total, 254 neonates were eligible with 109 neonates with HCA (42.9%). In multivariate analysis adjusting for GA, sex, and cesarean section, ACS use was associated with reduced severe bronchopulmonary dysplasia (BPD) or death and hypotension within 7 postnatal days among the neonates with HCA. However, it was associated with increased patent ductus arteriosus (PDA) treatment. In the optimal ACS group, severe BPD or death (aOR 0.03, 95% CI 0.01-0.42), hypotension (aOR 0.02, 95% CI 0.01-0.26), and inhaled nitric oxide use (aOR 0.06, 95% CI 0.00-0.81) were lower, however, PDA treatment (aOR 8.14, 95% CI 1.20-55.24) and sepsis (aOR 6.85, 95% CI 1.02-46.07) were higher when compared with the no ACS group among HCA+ infants. Among HCA- infants, only PDA treatment was lower in the ACS group.

CONCLUSION

In neonates with HCA, ACS treatment was associated with reduced morbidities. However, increased sepsis was associated with optimal ACS use.

Inflammation-induced preterm lung maturation: lessons from animal experimentation

Intrauterine inflammation, or chorioamnionitis, is a major contributor to preterm birth. Prematurity per se is associated with considerable morbidity and mortality resulting from lung immaturity but exposure to chorioamnionitis reduces the risk of neonatal respiratory distress syndrome (RDS) in preterm infants. Animal experiments have identified that an increase in pulmonary surfactant production by the preterm lungs likely underlies this decreased risk of RDS in infants exposed to chorioamnionitis. Further animal experimentation has shown that infectious or inflammatory agents in amniotic fluid exert their effects on lung development by direct effects within the developing respiratory tract, and probably not by systemic pathways. Differences in the effects of intrauterine inflammation and glucocorticoids demonstrate that canonical glucocorticoid-mediated lung maturation is not responsible for inflammation-induced changes in lung development. Animal experimentation is identifying alternative lung maturational pathways, and transgenic animals and cell culture techniques will allow identification of novel mechanisms of lung maturation that may lead to new treatments for the prevention of RDS.

Umbilical cord gene expression reveals the molecular architecture of the fetal inflammatory response in extremely preterm newborns

BACKGROUND

The fetal inflammatory response (FIR) in placental membranes to an intrauterine infection often precedes premature birth raising neonatal mortality and morbidity. However, the precise molecular events behind FIR still remain largely unknown, and little has been investigated at gene expression level.

METHODS

We collected publicly available microarray expression data profiling umbilical cord (UC) tissue derived from the cohort of extremely low gestational age newborns (ELGANs) and interrogate them for differentially expressed (DE) genes between FIR and non-FIR-affected ELGANs.

RESULTS

We found a broad and complex FIR UC gene expression signature, changing up to 19% (3,896/20,155) of all human genes at 1% false discovery rate. Significant changes of a minimum 50% magnitude (1,097/3,896) affect the upregulation of many inflammatory pathways and molecules, such as cytokines, toll-like receptors, and calgranulins. Remarkably, they also include the downregulation of neurodevelopmental pathways and genes, such as Fragile-X mental retardation 1 (FMR1), contactin 1 (CNTN1), and adenomatous polyposis coli (APC).

CONCLUSION

The FIR expression signature in UC tissue contains molecular clues about signaling pathways that trigger FIR, and it is consistent with an acute inflammatory response by fetal innate and adaptive immune systems, which participate in the pathogenesis of neonatal brain damage.

Very Low Birth Weight Monochorionic Diamniotic Twins as a Risk Factor for Symptomatic Patent Ductus Arteriosus

BACKGROUND

Some prior studies have shown that symptomatic patent ductus arteriosus (sPDA) is highly familial. Although it is estimated that both genetic and environmental factors may contribute to sPDA, evidence is still lacking.

OBJECTIVE

The aim of this study was to determine the risk factors for sPDA, focusing on the genetic and in utero environment by analyzing very low birth weight (VLBW) singletons and twins.

METHODS

This retrospective case-control study reviewed the medical records of 445 VLBW infants (25 weeks ≤ gestational age <32 weeks, 600 g ≤ birth weight <1,500 g) and compared the incidence of sPDA among monochorionic diamniotic (MD) twins (n = 65), dichorionic diamniotic (DD) twins (n = 66), and singletons (n = 314).

RESULTS

Stepwise multiple regression analysis showed that twin siblings (p = 0.001), gestational week (p < 0.001), antenatal steroid use (p = 0.021), and premature rupture of membranes (p = 0.002) were independent predictors of sPDA. Incidence of sPDA in MD twin siblings was significantly higher than that in singletons (p < 0.01), whereas no significant difference was found between singletons and DD twins or between MD and DD twins.

CONCLUSIONS

The current results show that being a VLBW MD twin is an independent risk factor for sPDA, and that both genetic and in utero environmental factors may contribute to its development.

Long-term outcomes of antenatal corticosteroids treatment in very preterm infants after chorioamnionitis

PURPOSE

To evaluate the effect of antenatal corticosteroids (AC) therapy on short- and long-term outcomes among very low birth weight preterm infants after histologic chorioamnionitis (HCA).

METHODS

We performed a retrospective analysis of 5240 single very low birth weight (VLBW) infants born at 22 + 0 and 33 + 6 weeks of gestation between 2003 and 2007, who registered to the Neonatal Research Network Japan. The effects of AC therapy on mortality, neurodevelopmental outcomes at 3 years of age and neonatal morbidities were analyzed in the groups with or without HCA using logistic regression analysis.

RESULTS

In the study subjects, 840 were with HCA, 2734 were without HCA, and 1666 were excluded without data for HCA. AC therapy was significantly associated with decreasing mortality before 3 years of age; [0.52 (0.32-0.86)], [odds ratio (95 % confidence intervals]. There were no differences between the two groups regarding neurodevelopmental outcomes, including cerebral palsy [0.90 (0.41-1.99)], development quotient <70 [0.93 (0.48-1.81)], visual impairment [0.46 (0.04-5.18)], and severe hearing impairment [4.00 (0.30-53.4)] in the group with HCA as well as without HCA. Regarding neonatal morbidities, AC therapy was associated with a lower incidence of respiratory distress syndrome [0.67 (0.50-0.91)], sepsis [0.62 (0.41-0.94)], late-onset adrenal insufficiency [0.62 (0.39-0.98)] and an increased incidence of chronic lung disease [1.62 (1.18-2.24)] in the group with HCA. In the group without HCA, AC therapy was associated with decreasing respiratory distress syndrome [0.60 (0.43-0.84)] and increasing chronic lung disease [1.34 (1.11-1.62)].

CONCLUSION

AC therapy is significantly associated with reduced mortality before 3 years of age in VLBW infants with HCA, but not with neurodevelopmental outcomes, which was same as the results found in infants without HCA. AC therapy is recommended for women with suspected chorioamnionitis, as well as those without chorioamnionitis.

Chorioamnionitis: implications for the neonate

Chorioamnionitis (CA) is characterized by inflammation of the fetal membranes. The incidence increases with decreasing gestational age at birth. When suspected on clinical criteria, pathologic assessment of the placenta should be performed. Although the mechanisms are not entirely clear, CA predisposes to premature birth, neonatal sepsis, and intraventricular hemorrhage. Its role in respiratory distress syndrome, bronchopulmonary dysplasia, and neurodevelopmental impairment is mixed. Prevention and treatment are ill-defined; antibiotics for preterm premature rupture of membranes reduce the incidence and increase the length of time to delivery. Antibiotics are recommended for infants exposed to CA while laboratory studies are being performed.

The Story of Antenatal Steroid Therapy before Preterm Birth

Antenatal glucocorticoid has proven to be one of the most successful single therapeutic approaches for preventing serious consequences after preterm birth. The fetal compartment is protected against endogenous corticosteroid by the high endogenous 11β-hydroxysteroid dehydrogenase type 2 that converts cortisol to cortisone and by the poor responsiveness of the fetal hypothalamus to corticotropin-releasing hormone. High corticosteroid activity acutely enhances the functional maturity of the fetus. Persistently high fetal glucocorticoid activity has adverse effects on the growth and differentiation of the fetal brain and other organs. Intrauterine growth restriction may be associated with high fetal glucocorticoid activity. Antenatal glucocorticoid therapy which is aimed to be given within 1-10 days before preterm birth is likely to increase the success of postnatal noninvasive treatments of very preterm infants.