Association of antenatal steroid exposure with survival among infants receiving postnatal life support at 22 to 25 weeks' gestation.

Abstract

Commentary on: Ehret, DEY, Edwards, EM, Greenberg, LT, Bernstein, IM, Buzas, JS, Soll, RF, Horbar, JD. Association of Antenatal Steroid Exposure with Survival Among Infants Receiving Postnatal Life Support at 22 to 25 Weeks’ Gestation. JAMA Netw Open. 2018; 1( 6): e183235. https://doi.org/10.1001/jamanetworkopen.2018.3235. The definition for limits of viability has been steadily declining for the past decade with increased survival of infants born at lower gestational ages 1. ACOG and SMFM criteria for periviable birth include infants delivered between 20 0/7 and 25 6/7 weeks of gestation. There are marked differences in reported survival from different centres and countries based on the perinatal care received, including counselling, antenatal steroids, magnesium sulphate use, approach to mode of delivery and resuscitation practices offered at delivery to lower gestational ages 2-4. Current ACOG guidelines recommend clinicians should evaluate aggressiveness of treatment provided to a 22-week gestation infant per family wishes but does not recommend antenatal steroid use 5. There is an urgent need for an accurate, objective and collaborative look at the short- and long-term outcomes of infants born at the edge of viability. This article is a multicenter, observational cohort study evaluating the survival, and survival without major morbidities, in periviable infants that received postnatal life support with or without benefits of ANS exposure. Analysis was done for overall cohort as well as by gestational ages. The study consistently showed that infants who received ANS prior to delivery at all gestational ages had higher survival and lower incidence of major morbidities among survivors. Although the difference in survival was most notable at the lowest gestational ages, the rate of survival without major morbidity remained extremely low. The study also reports that the percentage of infants offered postnatal life support was low for infants born at 22 weeks of gestation, possibly due to differential approaches among providers and lack of consensus. A major strength of this study is its size, possible only with a major national database such as VON, lending strong credibility to the results. A major limitation of the study is its retrospective design, which prevents capture of certain variables. The authors also note that the decision-making burden which lies on the families during the perinatal period, as well as their possibly limited understanding of long-term outcomes, may lead to disparate care provided to some of these infants. Another potential bias could be that these data are collected from NICUs equipped to handle periviable births, which could lead to an overestimation of survival in infants that were outborn. Additionally, there are possible unmeasured confounders related to practices at larger centres with targeted treatment strategies for these particular GA's leading to improved survival. This study does not look at long-term neurodevelopmental outcomes or the economic burdens suffered by these families and by society, which is of paramount importance in such infants with very high risks of short- and long-term consequences. The study concludes that infants that receive ANS with postnatal life support have higher survival and a decrease in major morbidities. However, survival without major morbidity remains low. This study will add vital information to the standardization of the care of infants at the edge of viability. Since clearly a randomized trial is unethical, large prospective cohort studies are needed to further guide practice. https://ebneo.org/2019/02/antenatal-steroid-exposure-survival/ None. None.