Characterization of prevalence, type, treatment, burden of disease and predictors of respiratory symptoms in very prematurely born children in the Zurich area (Frühgeborenen Lungen Projekt - FLiP)

Over the last three decades the prevalence of premature birth has risen due to changing demographics, higher mean age of pregnant mothers and a progressive use of reproductive medicine. Due to technological advances, improved care has further risen prevalence rates of very premature birth (<32 weeks of complete gestation). Surviving children are susceptible to severe neonatal morbidity that leads to long-term medical and social sequelae, often including respiratory disease. Lung injury due to immaturity, artificial ventilation, oxygen therapy and other factors can result in a wide range of pulmonary conditions. Respiratory limitations often extend beyond the neonatal period, and in some cases even into adulthood.

Despite several studies assessing the respiratory consequences of prematurity, there is significant variation in observed long-term pulmonary outcomes of premature birth. Most of these studies included heterogenous populations, frequently relatively small and selected samples and only a few studies assessed predictors of prematurity-related pulmonary sequelae. Studies that focused specifically on premature samples and with exhaustive perinatal care characterization covering different periods of standard treatment regimens over the last decade are scarce and cannot explain respiratory morbidity associated with prematurity. In addition, type of treatment and treatment burden for children and their parents are poorly studied and previous research is often limited to studies addressing the effects of steroids on the improvement of respiratory symptoms. So far, there is no report of other medications, no description of dosage, no treatment history, and no information of other treatment modalities. Thus, there is a clear lack of information on treatment of respiratory symptoms of premature children, response to treatment, and in particular how this affects children and their parents in respect to the disease and treatment burden.

In this study we aim to overcome some of the limitations of previous studies on the topic and perform a complete characterization of respiratory symptoms in survivors of very premature birth, using data of the larger Zurich area collected by the population-based registry of children born at preterm, the Swiss Neonatal Network & Follow-Up Group (SwissNeoNet). Specifically, we aim:

1) to assess the prevalence, type and severity of respiratory symptoms in children born <32 completed weeks of gestation between 2006 and 2019 in comparison to their siblings born at full-term;
2) to characterize the treatment and treatment burden of children and parents for respiratory symptoms;
3) to determine whether treatment of respiratory symptoms is related to respiratory improvement and
4) to assess the neonatal and sociodemographic predictors of respiratory symptoms in survivors of very preterm birth.

This is a cross-sectional observational study using an electronic survey.