Perinatal respiratory diseases and BPD
The perinatal period, i.e. the period from birth (and especially premature birth) to the 28th day of life, is the period of greatest mortality. Pre-term birth is the major determinant of neonatal mortality and morbidity. In the modern era, with survival of extremely premature infants (gestational age of ≤26 weeks) and low-birthweight infants, post-neonatal mortality contributes significantly to the infant mortality rate.
In a US survey in 2002, the neonatal mortality rate was 6.9 per 1000 babies born at 35–36 weeks, 18.5% in babies born at 30–34 weeks, and 28.5% among babies born at < 30 weeks. In a recent follow-up of 100 infants born at 23 weeks, 60 died prior to hospital discharge, most from respiratory failure. There is an increasing trend to initiate resuscitation and treatment at an earlier gestational age; however, it is concerning that this results in an increasing proportion of children with long-term respiratory and/or neurological impairment.
Hospital admission rates for perinatal respiratory disorders are presented in figure 4. It is unfortunate that data are not available from all countries, but it can be expected that, as in Switzerland, the UK, Italy, Poland and Cyprus, rates will increase across Europe and worldwide owing to the trend to start treatment at an earlier gestational age.
Another concern is the number of perinatal deaths in Europe (figure 5). Differences between western, central and eastern Europe are clearly apparent and may reflect variation in the quality of care available for these children. Also, more advanced equipment and expensive medication, such as surfactant, may not be available in some countries, whose health and budgetary priorities differ from those of western Europe.
One important long-term consequence of prematurity is BPD, or chronic lung disease of prematurity (CLD). This can be defined as oxygen dependency at 36 post-menstrual weeks. It is one of the most important complications of prematurity, with a reported incidence of 23% of infants born at 28 weeks, increasing to 73% of infants born at 23 weeks. It is characterised by prolonged respiratory support, compromised lung function and recurrent respiratory infections during the first year of life. Furthermore, BPD is considered an independent risk for and is associated with neurodevelopmental impairment.
Overall, therefore, there is concern about both the short- and long-term respiratory, but also developmental, consequences of treatment of very premature children. Attention needs to be paid to developing new and effective medication for children born with immature lungs. Until now, treatment for BPD has not been effective. There is a particular need to focus on the improvement of care for premature infants with these conditions in central and eastern Europe. Although lung function in children with BPD improves with age, impairment of lung function persists into adulthood, with impaired exercise capacity, airflow limitation and airway hyperreactivity. One has to take into account that these measurements are only available in children who are able to perform lung function tests. Since only limited data about the burden and the long-term effects of prematurity and BPD are available, the development of a European databank to study the costs, the cost-effectiveness and the long-term effects of treatment of these infants should be a priority so that information is available about the number of infants with BPD in each country and the long-term effects of extreme prematurity. In addition, guidelines for the treatment of these infants are needed, perhaps developed in conjunction with health organisations in other continents.