Congenital Critical Heart Defect Screening in a Health Area of the Community of Valencia (Spain): A Prospective Observational Study.

Despite the progress in the fetal echocardiographic detection of congenital critical heart defects and neonatal physical examination, a significant number of newborn infants are discharged and readmitted to the hospital in severe condition due to cardiac failure or collapse. The aim of this study was to assess the incidence of undetected critical congenital heart disease (CCHD) by a pulse oximetry-screening program in the maternity wards of hospitals with Perinatal Services in a specific geographic area. This is a prospective observational study performed in in the health area corresponding to the city of Valencia. Eligible infants were consecutively admitted newborn infants in the maternities of the participating hospitals with negative fetal echocardiography after normal physical examination in the delivery room. All patients were screened following a specific pulse oximetry protocol before discharge. A total of 8856 newborn infants were screened. A total of three babies presented with severe congenital cardiac malformation and two babies presented with early onset sepsis. Sensitivity was 100% and specificity was 99.97%, with a positive predictive value of 60% and negative predictive value of 100%. Pulse oximetry screening programs in the early neonatal period constitute a valuable tool to avoid inadvertent hospital discharge of severe cardiac malformations and the subsequent life-threatening complications derived.

Survival and Neurodevelopmental Outcomes of Preterms Resuscitated With Different Oxygen Fractions.

BACKGROUND AND OBJECTIVES: Stabilization of preterm infants after birth frequently requires oxygen supplementation. At present the optimal initial oxygen inspiratory fraction (Fio2) for preterm stabilization after birth is still under debate. We aimed to compare neurodevelopmental outcomes of extremely preterm infants at 24 months corrected age randomly assigned to be stabilized after birth with an initial Fio2 of 0.3 versus 0.6 to 0.65 in 3 academic centers from Spain and the Netherlands. METHODS: Randomized, controlled, double-blinded, multicenter, international clinical trial enrolling preterm infants <32 weeks' gestation assigned to an initial Fio2 of 0.3 (Lowox group) or 0.6 to 0.65 (Hiox group). During stabilization, arterial pulse oxygen saturation and heart rate were continuously monitored and Fio2 was individually titrated to keep infants within recommended ranges. At 24 months, blinded researchers used the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) to assess visual acuity, neurosensory deafness, and language skills. RESULTS: A total of 253 infants were recruited and 206 (81.4%) completed follow-up. No differences in perinatal characteristics, oxidative stress, or morbidities during the neonatal period were assessed. Mortality at hospital discharge or when follow-up was completed didn't show differences between the groups. No differences regarding Bayley-III scale scores (motor, cognitive, and language composites), neurosensorial handicaps, cerebral palsy, or language skills between groups were found. CONCLUSIONS: The use of an initial lower (0.3) or higher (0.6-0.65) Fio2 during stabilization of extremely preterm infants in the delivery room does not influence survival or neurodevelopmental outcomes at 24 months.

Protein-bound tyrosine oxidation, nitration and chlorination by-products assessed by ultraperformance liquid chromatography coupled to tandem mass spectrometry.

BACKGROUND: Free radicals cause alterations in cellular protein structure and function. Oxidized, nitrated, and chlorinated modifications of aromatic amino acids including phenylalanine and tyrosine are reliable biomarkers of oxidative stress and inflammation in clinical conditions. OBJECTIVE: To develop, validate and apply a rapid method for the quantification of known hallmarks of tyrosine oxidation, nitration and chlorination in plasma and tissue proteins providing a snapshot of the oxidative stress and inflammatory status of the organism and of target organs respectively. MATERIAL AND METHODS: The extraction and clean up procedure entailed protein precipitation, followed by protein re-suspension and enzymatic digestion with pronase. An Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method was developed to quantify protein released ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-nitrotyrosine (3NO2-Tyr) and 3-chlorotyrosine (3Cl-Tyr) as well as native phenylalanine (Phe) and tyrosine (p-Tyr) in plasma and tissue from a validated hypoxic newborn piglet experimental model. RESULTS: In plasma there was a significant increase in the 3NO2-Tyr/p-Tyr ratio. On the other hand m-Tyr/Phe and 3Cl-Tyr/p-Tyr ratios were significantly increased in liver of hypoxic compared with normoxic animals. Although no significant differences were found in brain tissue, a clear tendency to increased ratios was observed under hypoxic conditions. CONCLUSIONS: UPLC-MS/MS has proven suitable for the analysis of plasma and tissue samples from newborn piglets. The analysis of biomarkers of protein oxidation, nitration and chlorination will be applied in future studies aiming to provide a deeper insight into the mechanisms of oxidation-derived protein modification caused during neonatal asphyxia and resuscitation.

Novel biomarkers in amniotic fluid for early assessment of intraamniotic infection.

Intra-amniotic infection/inflammation (IAI) is associated with preterm birth, short and long-term adverse clinical outcomes and oxidative stress. The diagnosis of IAI is based on histological and clinical findings; however, often these results are unspecific. Therefore, efforts have been directed towards validating reliable methods for patients lacking overt clinical symptoms. In this study, amniotic fluid (AF) samples were prospectively collected from 23 women grouped into two categories (with or without IAI) following clinical, microbiological and histological criteria. AFs were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for the determination of the following biomarkers: oxidized and nitrated tyrosines (Tyr), 8-hydroxy-2'-deoxyguanosine (8OHdG), oxidized glutathione (GSSG) and glutathione sulfonamide (GSA). 3-NO2-Tyrosine (3NO2-Tyr) and GSSG concentrations in AF were not identified as significantly relevant biomarkers in the presence of IAI. However, inflammatory biomarkers such as GSA (p=0.002) and 3-Chloro-Tyrosine [3Cl-Tyr (p=0.049)], and oxidative stress biomarker 8OHdG (p=0.021) were significantly increased in AF with IAI as compared to normal controls. Biomarkers of inflammation and oxidative stress determined in AF samples could represent a new approach towards an early diagnosis of IAI and subsequent chorioamnionitis in the clinical setting.

Mass spectrometric detection of biomarkers for early assessment of intraamniotic fluid infection.

This data article contains information on glutathione sulfonamide (GSA) structural confirmation and purity after synthesis, as well as mass spectrometry acquisition parameters for the determination of GSA and other biomarkers for the early assessment of intraamniotic fluid infection in amniotic fluid samples (Cháfer-Pericás et al., 2015) [1]. GSA standards were synthesized and structural confirmation was carried out employing time-of-flight mass spectrometry (TOF-MS); purity was assessed by high performance liquid chromatography (HPLC) with UV detection. For optimization of the acquisition parameters of GSA and other biomarkers, individual analytical standard solution at a concentration of 1 µmol L(-) (1) was injected into an Acquity - Xevo TQ liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) system from Waters (Milford, MA, USA) operating in the positive electrospray (ESI(+)) mode. Mass spectrometric detection of 3-nitro-tyrosine (3NO2-Tyr), 3-chloro-tyrosine (3Cl-Tyr), 8-hydroxy-2'-deoxyguanosine (8OHdG), GSA and oxidized glutathione (GSSG) was carried out by multiple reaction monitoring (MRM). Linear response curves were calculated for each analyte normalizing the signal with peak areas of internal standards.

Administration of surfactant using less invasive techniques as a part of a non-aggressive paradigm towards preterm infants.

Traditional treatment of respiratory distress syndrome in preterm infants consisted of early intubation, mechanical ventilation and intra-tracheal administration of exogenous surfactant. Recently, non-invasive ventilation, which has shown some advantages in short- and long-term outcomes, has gained popularity for the initial management of respiratory insufficiency in preterm infants. However, non-invasive ventilation from the outset poses difficulties in relation to administration of exogenous surfactant. The customary INSURE technique requires tracheal intubation, surfactant administration, and rapid extubation, but the latter is not always possible. As a more elegant approach, several minimally invasive techniques of delivering surfactant have been developed for babies spontaneously breathing on CPAP. The most extensively studied have been those in which the trachea is briefly catheterized with a nasogastric tube or vascular catheter, and exogenous surfactant is administered. Although results seem promising they are not yet conclusive, and further studies will be needed to answer a number of outstanding questions.

Analysis of lipid peroxidation biomarkers in extremely low gestational age neonate urines by UPLC-MS/MS.

Extremely low gestational age neonates (ELGAN) frequently require the use of oxygen supply in the delivery room leading to systemic inflammation and oxidative stress that are responsible for increased morbidity and mortality. The objective of this study was to establish reference ranges of a set of representative isoprostanes and prostaglandins, which are stable biomarkers of lipid peroxidation often correlated with oxidative stress-related disorders. First, a quantitative ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated. The proposed analytical method was tailored for its application in the field of neonatology, enabling multi-analyte detection in non-invasive, small-volume urine samples. Then, the lipid peroxidation product concentrations in a total of 536 urine samples collected within the framework of two clinical trials including extremely low gestational age neonates (ELGAN) were analyzed. The access to a substantially large number of samples from this very vulnerable population provided the chance to establish reference ranges of the studied biomarkers. Up to the present, and for this population, this is the biggest reference data set reported in literature. Results obtained should assist researchers and pediatricians in interpreting test results in future studies involving isoprostanes and prostaglandins, and could help assessing morbidities and evaluate effectiveness of treatment strategies (e.g., different resuscitation conditions) in the neonatal field.

Assessment of oxidative damage to proteins and DNA in urine of newborn infants by a validated UPLC-MS/MS approach.

The assessment of oxidative stress is highly relevant in clinical Perinatology as it is associated to adverse outcomes in newborn infants. This study summarizes results from the validation of an Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of the urinary concentrations of a set of endogenous biomarkers, capable to provide a valid snapshot of the oxidative stress status applicable in human clinical trials, especially in the field of Perinatology. The set of analytes included are phenylalanine (Phe), para-tyrosine (p-Tyr), ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-NO2-tyrosine (3NO2-Tyr), 3-Cl-tyrosine (3Cl-Tyr), 2'-deoxyguanosine (2dG) and 8-hydroxy-2'-deoxyguanosine (8OHdG). Following the FDA-based guidelines, appropriate levels of accuracy and precision, as well as adequate levels of sensitivity with limits of detection (LODs) in the low nanomolar (nmol/L) range were confirmed after method validation. The validity of the proposed UPLC-MS/MS method was assessed by analysing urine samples from a clinical trial in extremely low birth weight (ELBW) infants randomized to be resuscitated with two different initial inspiratory fractions of oxygen.

Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups.

BACKGROUND: Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. OBJECTIVES: To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. MATERIAL AND METHODS: Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8-12 h prior to delivery and reset to 21% 6-8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glutamyl cysteine (γ-GC) and L-cysteine (CySH)] content and expression of several redox-sensitive genes were evaluated in newborn lung and brain tissue 1 (P1) and 7 (P7) days after birth. RESULTS: As compared with control animals, the GSH/GSSG ratio was increased in the hypoxic group at P1 and P7 in the lung, and at P7 in the brain. In the hypoxic group a significant increase in the mRNA levels of NAD(P)H:quinone oxidoreductase 1 (noq1), Sulfiredoxin 1 (srnx1) and Glutathione Peroxidase 1 (gpx) was found in lung tissue at P1, as well as a significant increase in gpx in brain tissue at P7. CONCLUSIONS: Delaying the increase in tissue oxygenation to occur after birth reduces short-and-long-term oxidative stress in the lung. Similar yet more subtle effects were found in the brain. Apparently, the fetal-to-neonatal transition under hypoxic conditions appears to have protective qualities.

Oxygen in the delivery room.

Immediately after birth the newly born infant aerates the lungs, diminishes pulmonary vascular resistance, and initiates gas exchange. However, under certain circumstances this process will not be adequately accomplished. Asphyxia is characterized by periods of hypoxia and ischemia leading frequently to hypoxic ischemic encephalopathy. The mainstay of newborn resuscitation resides in the establishment of a functional residual capacity and an adequate oxygenation. Recent guidelines have established guidelines which provide counsel on the use of oxygen in term infants. However, preterm oxygenation in the delivery room (DR) has only been defined very vaguely. Herewith, we will address available information regarding the use of oxygen supplementation in the DR both in term and preterm babies for a satisfactory postnatal adaptation.

Amniotic fluid oxidative and nitrosative stress biomarkers correlate with fetal chronic hypoxia in diabetic pregnancies.

BACKGROUND: In spite of improvement in obstetrical care, pregnancy in women with type 1 diabetes mellitus is associated with increased perinatal morbidity and mortality. Hyperglycemia during pregnancy causes excessive fetal growth and chronic fetal hypoxia as reflected in increased erythropoietin (EPO) levels in amniotic fluid (AF). OBJECTIVES: We hypothesized that the degree of fetal hypoxia would correlate with fetal oxidative and nitrosative stress as evidenced ty the concentration of specific biomarkers in AF. MATERIAL AND METHODS: 19 pregnant women with type 1 or insulin-treated gestational diabetes mellitus were studied. AF samples were collected and processed for EPO, meta-tyrosine, nitro-tyrosine and 8-hydroxy-2-deoxiguanosine by chemiluminescent immunoassay and high-performance liquid chromatography coupled to tandem mass spectrometry methods, respectively. RESULTS: The mean (SD) of the last HbA1c concentration before delivery was 7.7% (1.1). Median gestational age was 258 days (range 231-268). Birth weight was 3,868 ± 695 g with a z-score >2 SD in 47% of the cases. A significant correlation was found between the concentrations of AF EPO and meta-tyrosine/phenylalanine ratio (p < 0.001), nitro-tyrosine (p < 0.01) and 8-oxo-dG/2dG ratio (p < 0.001). CONCLUSIONS: We confirmed that fetuses of type 1 diabetes or insulin-treated gestational diabetes pregnancies experience chronic hypoxia as reflected by increased EPO concentrations in AF near term. Moreover, EPO levels significantly correlated with the concentration of oxidative and nitrosative stress biomarkers in AF. This pro-oxidant status may predispose newborn infants to poor postnatal adaptation and early neonatal complications.

Oxygen saturation after birth in preterm infants treated with continuous positive airway pressure and air: assessment of gender differences and comparison with a published nomogram.

AIMS: The goal of the study was to compare preductal SpO2 in the first 10 min after birth in preterm infants treated with non-invasive continuous positive airway pressure (CPAP) and air with a published nomogram of preductal SpO2 in preterm infants who received no medical intervention, and to examine gender differences. DESIGN: Prospective observational study. PATIENTS AND METHODS: We enrolled infants of ≤32 weeks gestation who were spontaneously breathing with heart rate >100 bpm, and treated with face mask CPAP and air during postnatal stabilisation. SpO2 limits were targeted at ≥75% at 5 min and ≥85% at 10 min and heart rate at >100 bpm. FIO2 was titrated against SpO2. Preductal SpO2, airway pressure and FIO2 were recorded with a data acquisition system from birth until stabilisation. Babies receiving supplemental oxygen (>21%), positive pressure ventilation, were intubated and/or received chest compressions or drugs were excluded. RESULTS: Measurements were obtained in 102 babies with median gestational age of 29 (range: 24-31) weeks. Median SpO2 was significantly higher in the observational group than in the reference range at 3 min (82% (CI 71% to 85%) vs 76% (CI 67% to 83%); p<0.05), at 4 min (87% (CI 81% to 90%) vs 81% (CI 72% to 88%); p<0.05), at 5 min (92% (CI 88% to 95%) vs 86% (CI 80% to 92%); p<0.05), at 6 min (94% (CI 90% to 97%) vs 90% (CI 81% to 95%); p<0.05), at 7 min (95% (CI 92% to 97%) vs 92% (CI 85% to 95%); p<0.05), at 8 min (96% (CI 93% to 98%) vs 92% (CI 87% to 96%); p<0.05) and at 9 min (97% (CI 92% to 99%) vs 93% (CI 87% to 96%); p<0.05). Female babies achieved targeted SpO2 significantly earlier than male babies. CONCLUSIONS: Preterm babies receiving CPAP and air and especially female subjects achieve reference oxygen saturation more rapidly than spontaneously breathing preterm babies without respiratory aid.

Sex-dependent changes in the pulmonary vasoconstriction potential of newborn rats following short-term oxygen exposure.

BACKGROUND: Chronic exposure to supplemental oxygen (O(2)) induces lung damage and mortality in a sex-dependent manner. The effect of short-term hyperoxia on the newborn pulmonary vasculature is unknown but is, however, of clinical significance in the neonatal resuscitation context. We hypothesize that short-term hyperoxia has a sex-dependent effect on the pulmonary vasculature. METHODS: Following 1-h 100% O(2) exposure, the pulmonary arteries and lung tissues of newborn rats were evaluated. RESULTS: Superoxide dismutase 3 (SOD3) expression in female pups' lungs was increased as compared with that in the lungs of male pups. As compared with air-treated pups, the response of male pups to thromboxane was increased by O(2), whereas the opposite effect was documented in the vessels of female pups. The enhanced force of hyperoxia-exposed arteries of the male pups was suppressed with superoxide or peroxynitrite scavengers, and increased lung SOD activity and hydrogen peroxide content were seen in female, but not in male, rats. Hyperoxia induced an increase in lung tissue oxidative products and Rho-kinase (ROCK) activity in male, but not in female, pups. CONCLUSION: A lower lung SOD content and failure to upregulate SOD activity facilitates peroxynitrite generation and ROCK activation in hyperoxia-exposed males, predisposing them to pulmonary vasoconstriction. These observations, if relevant to humans, may explain the increased mortality and higher incidence of pulmonary hypertension in male neonates.

Oxygen saturation targets for preterm infants in the delivery room.

Fetal life evolves in a low oxygen milieu as compared to the extra-uterine. In the fetal to neonatal transition rapid changes in the oxygen content of the newly born infant occur within a brief period of time. Delivery room care givers should be aware of the slow transition regarding oxygenation, and supply oxygen as needed trying to avoid damage caused by hyper-and-hypoxia. In this regard, titrating oxygen inspiratory fraction against oxygen saturation as measured by pulse oximetry following recent nomogram ranges is a valid method.