Changes in perinatal management and outcomes in infants born at 23 weeks of gestational age during the last decade in Spain.

INTRODUCTION: The 2021-updated guidelines of the Spanish Society of Neonatology Guidelines have moved the zone of parental discretion to 23 + 0-23 + 6 weeks. The objective of this study was to describe the changes in perinatal management at this gestational age along the last decade and to determine if a more active perinatal management has contributed to improved outcomes. METHODS: Retrospective analysis of prospectively collected data from the 23-week infants included in the Spanish SEN 1500 neonatal network during the period 2010-2019. The main study outcomes were survival at discharge and survival without major morbidity of actively managed infants. Two periods were compared: 2010-2014 (Period 1) and 2015-2019 (Period 2). NICUs were classified into low activity NICUs (less than 50 admissions of very low birth weight infants per year) and high activity NICUs (50 or more admissions). RESULTS: A total of 381 infants were included, 182 in Period 1 and 199 in Period 2. In Period 2 an increase in the use of intrapartum magnesium sulfate (21.5% vs 39.9%, p .002), antenatal steroids (56.6% vs 69.3%, p .011) and active neonatal approach in delivery room (76.9% vs 86.9%, p .011) were observed.The clinical outcomes of the actively managed 313 infants were similar in both periods, except for less arterial hypotension in Period 2. Survival was 27.1% in Period 1 and 25% in Period 2 (p .068) and survival without major morbidity was 2.1% and 2.3% respectively (p .914). No difference was found between low and high activity NICUs. CONCLUSION: A change to a more active intention to treat infants born at 23 weeks is taking place in Spain. But the survival rate of the actively-managed infants has remained stable around 25-30% during the study period. A multidisciplinary effort is needed to improve outcomes in this population.

Age-related differences in vasoconstrictor responses to isoprostanes in piglet pulmonary and mesenteric vascular smooth muscle.

Isoprostanes are prostaglandin (PG)-like compounds produced nonenzymatically by free radical-catalyzed peroxidation of arachidonic acid. Isoprostanes evoke potent vascular effects but their actions in the neonatal vasculature are poorly known. We aimed to study the effects of 8-iso-PGE(1), 8-iso-PGE(2), 8-iso-PGF(1alpha), 8-iso-PGF(1beta), 8-iso-PGF(2alpha), and 8-iso-PGF(2beta) in pulmonary arteries (PA), pulmonary veins (PV), and mesenteric arteries (MA) from newborn and 2-wk-old piglets. Isoprostanes produced concentration-dependent contractions of PA, PV, and MA (magnitudes up to 1.5- to 2-fold greater than the responses to 62.5 mM KCl) but they were markedly less potent vasoconstrictors than the thromboxane A(2) (TXA(2)) mimetic U46619. Neonatal PA were more sensitive to 8-iso-PGF(1alpha), 8-iso-PGF(1beta), and 8-iso-PGF(2beta) than 2-wk-old PA. Neonatal PV were more sensitive to 8-iso-PGE(2) and 8-iso-PGF(1alpha), and neonatal MA were more sensitive to 8-iso-PGE(2), 8-iso-PGF(1alpha), 8-iso-PGF(1beta), 8-iso-PGF(2alpha), and 8-iso-PGF(2beta) than the corresponding 2-wk-old vessels. The sensitivity to U46619 decreased with postnatal age in MA but did not change in PA and PV. The contractile responses to all the isoprostanes and to U46619 were reverted by the TXA(2) receptor (TP) antagonist SQ 29,548. Moreover, isoprostane-evoked contractions in 2-wk-old PA were reduced by inhibitors of tyrosine kinase (genistein) and Rho kinase (Y 27632 and hydroxyfasudil) but not by inhibitors of protein kinase C (chelerythrine), mitogen-activated protein kinase kinase (PD 98059) or p38-kinase (SB 203580). In conclusion, isoprostanes produced compound-, tissue-, and age-dependent constriction of neonatal porcine pulmonary and mesenteric vascular smooth muscle. Isoprostane-evoked PA vasoconstriction involved TP receptors and activation of tyrosine kinases and Rho kinases.