ERS | monograph Introduction Ian P. Sinha1,2, Jayesh Mahendra Bhatt 3 , Alex Cleator4 and Helen Wallace5 @ERSpublications The early years are crucial for lung health through the life course. This Monograph comprises state-of-the-art reviews about neonatal respiratory problems. https://bit.ly/3h2V7pd Those of us lucky enough to work with babies know that our decisions and actions – whether right or wrong – have a lifelong impact for our patients and their families. This is profoundly evident with the respiratory system. Crammed within the thorax of adults reading this Monograph is a beautifully intricate respiratory system with an alveolar surface area the same as Wimbledon’s Centre Court, and capillaries that, end-to-end, would stretch from Liverpool to Rome. It is delicate enough to enable gas exchange that keeps us alive, yet robust enough to withstand all the adverse exposures thrown at it. This system begins to develop only a few weeks after conception, and continues to grow into adulthood. In this Monograph, we consider the respiratory system in the neonatal phase of this lifelong journey. We begin with summaries of the structure and function of the respiratory system, and how it develops [1, 2]. We felt this would be an appropriate manner in which to start a Monograph about diseases of the newborn lung: without understanding how the respiratory system should work, we do not know how to support and protect it. We move on to discuss the problems the respiratory system faces when babies are born prematurely [3–10]. One in 10 babies is born too early, and the limits of viability are moving earlier and earlier. In medical speciality terms, neonatology is still itself just a baby, but progress has been staggering – BPD was only described 50 years ago, and since then NICUs around the world have helped millions of premature babies, who are some of the most vulnerable and clinically unstable people imaginable. This has only been made possible by excellent research, service development, audit, education and collaboration. The goals of neonatal care are now not just to keep babies alive but to do so with the least possible damage, so that they can go on to live happy, healthy lives. We aimed to reflect that in this section of the Monograph, with chapters describing the respiratory care of preterm infants at birth and in the neonatal unit [3], and in clinic after they are discharged [4–10]. We also recognise that it is not always appropriate to keep babies alive at all costs Copyright ©ERS 2021. Print ISBN: 978-1-84984-136-8. Online ISBN: 978-1-84984-137-5. Print ISSN: 2312-508X. Online ISSN: 2312-5098. Correspondence: Ian P. Sinha, Respiratory Unit, Alder Hey Children’s Hospital, Liverpool, L12 2AP, UK. E-mail: iansinha@liverpool.ac.uk 1 Respiratory Unit, Alder Hey Children’s Hospital, Liverpool, UK. 2 Division of Child Health, University of Liverpool, Liverpool, UK. 3 Dept of Respiratory Paediatrics, Nottingham Children’s Hospital, Nottingham University Hospitals NHS Trust, Queen’s Medical Centre, Nottingham, UK. 4 Neonatal Medicine, Liverpool Women’s Hospital, Liverpool, UK. 5 Dept of Women and Children’s Health, University of Liverpool, Liverpool, UK. https://doi.org/10.1183/2312508X.10006621 ix