Corticoterapia prenatal y morbimortalidad del prematuro tardío: estudio prospectivo

Does the use of antenatal corticosteroids reduce respiratory morbidity in babies born in late preterm period?

BACKGROUND

The aim of this study is to determine the effectiveness of antenatal corticosteroid in reducing respiratory morbidity in babies born in the late preterm period.

METHODS

Two hundred and eighty-six pregnant women at risk of having a late preterm delivery were studied. One hundred and forty-three (143) served as the cases and were given 2 doses of 12 mg intramuscular dexamethasone 12 h apart, while 143 served as the controls and were given a similar quantity of placebo. The women were followed up prospectively and data were collected on the pregnant women and their newborns on a standardized form. The neonates were assessed for acute respiratory distress syndrome and transient tachypnea of the newborn based on clinical signs, symptoms, and chest x-ray results (when indicated). The primary outcome was the occurrence of neonatal respiratory morbidity.

RESULTS

The primary outcome occurred in 5 out of 130 infants (3.8%) in the dexamethasone group and 31 out of 122 (25.4%) in the placebo group (P value = 0.000003). Birth asphyxia, neonatal intensive care admission and need for active resuscitation at birth also occurred significantly less frequently in the dexamethasone group (P value 0.004, 0.009, 0.014 respectively). There were no significant group differences in the incidence of neonatal sepsis, neonatal jaundice, hypoglycemia and feeding difficulties.

CONCLUSIONS

Administration of dexamethasone to women at risk for late preterm delivery significantly reduced the rate of neonatal respiratory complications, neonatal intensive care unit admission, and need for active resuscitation at birth.

TRIAL REGISTRATION

PACTR ( www.pactr.org ) Registration Number: PACTR202304579281358. The study was retrospectively registered on April 19, 2023.

The use of late preterm antenatal corticosteroids in women with gestational diabetes : a puzzle worth solving

BACKGROUND

To investigate the association between late preterm antenatal corticosteroid treatment and outcome in late preterm neonates born to mothers with gestational diabetes mellitus, METHODS: All patients with gestational diabetes mellitus who had a late preterm delivery at Etlik Lady Zübeyde Hospital between 2017 and 2021 were included. Women who met the inclusion criteria and were not given antenatal corticosteroid treatment during current pregnancy before 34 0/7 weeks of gestation were divided into two groups according to whether or not they received late preterm antenatal corticosteroid treatment. The two groups were compared in terms of adverse neonatal complications. The main outcomes were composite respiratory outcome and composite neonatal outcome. Logistic regression analysis was used to determine additional potential predictors of neonatal outcome.

RESULTS

This retrospective cohort study included a total of 400 participants with gestational diabetes mellitus who had a late preterm delivery within the study period. Of these women, 196 (49%) received late preterm antenatal corticosteroid treatment. Main outcomes showed no difference. Decreasing gestational age at birth was identified as an independent risk factor predicting both composite respiratory outcome and composite neonatal outcome in multivariate logistic regression analysis.

CONCLUSIONS

Antenatal corticosteroid treatment at or after 34 0/7 weeks of gestation in women with gestational diabetes mellitus who had a late preterm delivery was not associated with improvement in adverse neonatal outcomes. Decreasing gestational age at birth was the only independent risk factor predicting composite neonatal and composite respiratory outcomes.

Evaluation of cerebral autoregulation of oxygen by NIRS method during postnatal transition period in term and late preterm newborns without resuscitation requirement

BACKGROUND

Pulse oximetry is commonly used to monitor arterial oxygen saturation and heart rate during the transition period and reference intervals have been determined. However, the effect of the change in arterial oxygen saturation on tissue oxygenation does not seem to be the same. So, a non-invasive method for monitoring cerebral or regional tissue oxygenation will be potentially useful for vulnerable infants. This study aims to evaluate the effectiveness of cerebral autoregulation in the first 10 min after delivery in term and late preterm newborns without resuscitation requirement.

METHODS

Cerebral tissue oxygen saturation was measured in the first 10 min after birth with near-infrared spectroscopy (NIRS) from the left forehead. Peripheral oxygen saturation was measured with pulse oximetry from the right hand and cerebral fractional tissue oxygen extraction was calculated.

RESULTS

Nineteen late preterms and 20 term infants were included in the study. There was no statistically significant difference between median cerebral tissue oxygen saturation and cerebral fractional tissue oxygen extraction values of late preterm and term infants (p < 0.001). There was a strong inverse relationship between cerebral tissue oxygen saturation and cerebral fractional tissue oxygen extraction (p < 0.001).

CONCLUSIONS

In late preterm infants similar to term infants, arterial oxygen saturation and cerebral tissue oxygen saturation increased with time, but inverse reduction of cerebral fractional tissue oxygen extraction showed the presence of an active autoregulation in the brain. This can be interpreted as the ability of the brain to protect itself from hypoxia by regulating oxygen uptake during normal fetal-neonatal transition process. A larger scale multi-center randomized control trial is now needed to further inform practice.

Prenatal glucocorticoid administration enhances bilirubin metabolic capacity and increases Ugt1a and Abcc2 gene expression via glucocorticoid receptor and PXR in rat fetal liver

AIM

Jaundice is especially common in premature infant born before 35 weeks. Because the premature infant liver is not fully developed at birth it may be incomplete the bilirubin metabolism. The purpose was to evaluate the metabolism and the excretion of bilirubin in the premature infant rat liver following prenatal glucocorticoid (GC) administration.

METHODS

Dexamethasone (DEX) was administered subcutaneously to pregnant Wistar rats for two consecutive days on gestational days 17 and 19. The fetus were delivered by cesarean section in gestational days 19 and 21. The mRNA levels and protein levels of bilirubin-metabolic enzymes and transporters in the fetal liver tissues were analyzed using RT-PCR immunohistochemistry staining and ELISA, respectively. We evaluated that the effect of bilirubin-metabolic enzymes in the primary fetal rat hepatocytes treated with DEX after pretreated with glucocorticoid receptor (GR, Nr3c1) and Pxr (Nr1i2) siRNA.

RESULTS

Ugt1a1 and Bsep (Abcb11) mRNA levels were significantly increased in the fetuses by prenatal GC administration. The mRNA levels of nuclear transcription factors Nr1i2, Car (Nr1i3), and Rxrα (Nr2b1) were also significantly increased in the fetuses by prenatal GC administration. In addition, DEX increased Nr1i2, Ugt1a1, and Abcc2 (Mrp2) mRNA levels in the primary fetal hepatocytes. The Nr3c1 or Nr1i2 siRNA-mediated knockdown suppressed the increases of Ugt1a1, and Abcc2 mRNA levels induced by DEX, indicating that DEX are mediated by GC receptor and PXR in primary fetal hepatocytes.

CONCLUSIONS

These results suggest that prenatal GC administration increases bilirubin-metabolic ability, in the premature liver, which may prevent jaundice in neonates.

A Comparative Study of the Respiratory Neonatal Outcomes Utilizing Dexamethasone Sodium Phosphate versus a Mixture of Betamethasone Dipropionate and Betamethasone Sodium Phosphate as an Antenatal Corticosteroid Therapy

Objective

The aim of this study is to compare the respiratory neonatal outcomes utilizing antenatal dexamethasone sodium phosphate (DSP) versus a mixture of betamethasone dipropionate and betamethasone sodium phosphate (B-DP/SP) for preterm births.

Patients and Methods

All neonatal intensive care unit (NICU) admissions for prematurity were retrospectively identified at our center in the period between September 2016 and September 2018. Pregnant women expected to give preterm birth and received steroid injections whether it is DSP or B-DP/SP were included in the study. Maternal and obstetrical data along with the corresponding respiratory neonatal outcomes were extracted and analyzed. The population was categorized according to the gestational age into extremely preterm (less than 28 weeks), very preterm (28 up to 32 weeks) and moderate or late preterm (32 up to 37 weeks) in which the repository outcomes were compared in each sub-group.

Results

A total of 650 premature neonates were included in the analysis. B-DP/SP illustrated a significant reduction in the occurrence of respiratory distress syndrome (RDS) among moderate or late preterm neonates (P = 0.003) compared to DSP. In contrast, a non-significant difference was observed between B-DP/SP and DSP regarding apnea of prematurity and transient tachypnea of the newborn. The number of neonates developed chronic lung disease has been remarkably reduced when using DSP in extremely (P = 0.038) and very (P = 0.046) preterm neonates when compared to B-DP/SP.

Conclusion

The dual acting B-DP/SP formulation could possess a significant potential in reducing RDS in moderate or late preterm neonates, while DSP groups exhibit a favorable result in the development of chronic lung disease in extreme and very preterm cohorts. Such findings emphasize the need of further clinical trials, pharmacokinetics, pharmacodynamics and cost effectiveness studies to evaluate the durability of these findings.

The Shift of HbF to HbA under Influence of SKA2 Gene; A Possible Link between Cortisol and Hematopoietic Maturation in Term and Preterm Newborns

BACKGROUND

We hypothesized that the SKA2 gene can convert hemoglobin F to A leading to the maturity of the hematopoietic system by glucocorticoid hormone; so, the present study aimed to investigate the health outcome of newborns by using the effect of SKA2 gene on hematopoietic maturation.

METHODS

At first, 142 samples were divided into term and preterm. After sampling from the umbilical cord blood, the expression of SKA2 genes and HbA and F were evaluated by quantitative RT-PCR. The blood gases were measured by Campact 3 device. Finally, the cortisol level was measured by ELISA method and HbA and F levels were investigated by capillary electrophoresis.

RESULTS

The blood gases and Apgar scores were more favorable in term newborns (P <0.001). Levels of protein/expression of HbF in newborns with Apgar score greater than 7 was lower than that of the newborns with Apgar score below 7 (P <0.001). Cortisol and HbA levels were considerably higher in term newborns compared to the preterm ones (P <0.001). In the preterm and term groups, SKA2 gene expression had a positive and significant relationship with cortisol and HbA levels as well as a negative relationship with the HbF level. In the preterm group, a positive and significant relationship was observed between the expression of SKA2 and HbF genes.

CONCLUSION

The results revealed that the SKA2 gene affected hematopoietic maturation in preterm and term newborns and the health outcome of newborns improved by increasing HbA level.

[Neonatal morbidity and mortality associated with low adherence to prenatal corticosteroids]

INTRODUCTION

Prenatal corticosteroids reduce neonatal mortality and morbidity; however, there are few studies in developing countries, and with inconsistent results. The purpose of this study was to quantify the frequency of the use of prenatal corticosteroids and to estimate its effect on the morbidity and mortality of premature newborns.

METHODS

A retrospective cohort study was performed on premature newborns selected from a census conducted between January 2016 and August 2017. The use of corticosteroids was taken from the maternal records, and the dependent variables from the neonatal records. An analysis was made of the relationship using logistic regression, adjusted to gestational age and weight.

RESULTS

The study included 1083 premature infants of which 53.3% were male. The mean gestational age was 33.4 weeks. Corticosteroids were received by 42%, with latency ≥24hours in 23.6% and ≥48hours in 13.8%. Respiratory distress syndrome was observed in 35% (379/1083), early neonatal sepsis in 4.4% (48/1083), late neonatal sepsis in 10.7% (116/1083), intraventricular haemorrhage in 15.1% (137/908), chronic lung disease in 51.4% (165/321), and death in 22.3% (242/1083). Prenatal corticosteroids decreased the risk of death in children under 34 weeks (OR 0.63, 95% CI 0.40-0.98). The decrease was greater if they presented with latency ≥48hours (OR 0.40, 95% CI 0.20-0.80). The rest of the dependent variables were not modified by the intervention.

CONCLUSIONS

In preterm infants, 42% received antenatal corticosteroids. In those with less than 34 weeks, there was a decrease in the risk of death without changes in morbidity.

Factors relating caesarean section to persistent pulmonary hypertension of the newborn

BACKGROUND

Several studies have clearly demonstrated a significantly higher incidence of persistent pulmonary hypertension of the newborn (PPHN) in neonates delivered by caesarean section (CS) compared to those delivered vaginally. The pathophysiological factors underlying the link between CS and PPHN are still poorly understood. In this review, we describe the mechanisms that could explain the association between CS delivery and subsequent PPHN, as well as potential preventive measures.

DATA SOURCES

A literature search was conducted by electronic scanning of databases such as PubMed and Web of Science using the key words "persistent pulmonary hypertension of the newborn", "caesarean section", "iatrogenic prematurity", "oxidative stress", "late preterm", "labor" and "vasoactive agents".

RESULTS

Iatrogenic prematurity, higher rates of late preterm delivery and lack of physiological changes of labor play an important role in the association between CS and PPHN. CS delivery also results in limited endogenous pulmonary vasodilator synthesis and lower levels of protective anti-oxidants in the neonates. In addition, CS delivery exposes infants to a higher risk of respiratory distress syndrome and its concomitant increase in endothelin-1 levels, which might indirectly lead to a higher risk of developing PPHN. We believe that neonates delivered by CS are exposed to a combination of these pathophysiological events, culminating in an endpoint of respiratory distress, hypoxia, acidosis, and delayed transition and thereby increased risks of PPHN. The use of antenatal corticosteroids prior to elective CS in late preterm deliveries, promoting accurate informedconsent process, delaying elective CS to 39 weeks of gestation or beyond and antenatal maternal anti-oxidant supplementation could potentially mitigate the effects of CS delivery and minimize CS-related PPHN.

CONCLUSIONS

The link between CS delivery and PPHN is complex. In view of the rising rates of CS worldwide, there is an urgent need to further explore the mechanisms linking CS to PPHN and experimentally test therapeutic options in order to allow effective targeted interventions.

The transition from intra to extra-uterine life in late preterm infant: a single-center study

BACKGROUND

Infants born at 34 to 36 weeks of gestation (late preterm) are at greater risk for adverse outcomes than those born at 37 weeks of gestation or later. Aim of this paper is to examine risk factors for late preterm births and to investigate the complications of the transition period in late preterm infants (LPIs).

METHODS

All consecutive late preterm deliveries, excluded stillbirths, were included. Maternal and neonatal data, need for delivery room resuscitative procedures, temperature at birth (T1) and two hours after the admission (T2) were analyzed in all LPIs stratified by Gestational Age (GA) and divided into three groups (34, 35 and 36 weeks).

RESULTS

Two hundred seventy-six LPIs were analyzed. Pregnancy complications were present in 72 mothers (26.1 %), more frequently at 34 weeks of gestation respect to 35 and 36 weeks (p = 0.008, p = 0.006 respectively). Forty seven LPIs (17.1 %) needed for any resuscitation and 37 (13.4 %) were ventilated at birth. LPIs at 34 weeks were significantly more likely to receive ventilation respect to those at 35 and 36. At T1 the mean temperature resulted lower at 34 weeks respect to 36 weeks (p = 0.03). At T2 respect to T1, the rate of normothermic neonates increased at 35 and 36 weeks (p = 0.003, p = 0.005, respectively). Hypoglicemia rate was similar among the groups; 66.7 % of hypoglicemic neonates were hypothermic at T1. The rate of respiratory diseases and NICU admission decreased with increasing GA. Higher number of neonates ventilated at birth developed respiratory disorders respect to those unventilated (40.5 % vs 8.4 %; p < 0.001).

CONCLUSIONS

Transition period in LPIs may become critical, as resuscitation strategies can be required and heat loss can occur. LPIs, especially at 34 gestational weeks, are higher-risk group needing adequate and targeted management at birth.