Harmonisation Study / EPT RECAP

EPT RECAP - A comparative analysis of extremely preterm birth cohorts in Europe participating in the RECAP consortium

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#### Objectives: 1. Identify similarities and differences between European birth cohorts that are potentially important in the determination of baseline populations used in perinatal epidemiology (for example, fetuses alive at presentation to hospital and the onset of labour or the time a decision was made to perform Caesarean section; live births; babies admitted to neonatal intensive care). 2. Investigate the impact of sex differences on short-term outcomes – specifically, survival to hospital discharge, and the occurrence of neonatal morbidities (for example, intraventricular haemorrhage, chronic lung disease, necrotising enterocolitis, retinopathy of prematurity). 3. Quantify the impact of population differences on survival, with a particular focus on survival time. 4. Investigate and provide crude outcome data for subgroups that are insufficiently represented in individual cohorts (e.g. multiple pregnancies, IVF pregnancies, diabetic mothers) but which might potentially be used as the baseline for future studies. 5. Assess the impact of using different neurodevelopmental outcome definitions at 18 to 48 months corrected age in line with the use of varied baseline populations. 6. Determine the feasibility of investigating rare outcomes (for example, visual or hearing impairment) within the confines of potential difficulties such as comparability of assessment tools, data harmonisation, or the technical restrictions of the platform required to maintain subject confidentiality.


Investigators Contacts
  • Jennifer Zeitlin
    INSERM UMR 1153
  • Helen Collins
    University of Leicester
  • Gonçalo Gonçalves
  • Andrei Morgan
    INSERM UMR 1153

Study Design

This study will make use of federated nodes containing perinatal and follow-up data for extremely preterm cohorts involved in the RECAP consortium. The ‘DataSHIELD’ package from R will be used to perform a distributed analysis. The study will be conducted in close collaboration with the team cataloguing and harmonising data for RECAP (Work Package 3 – WP3). Work is currently on-going by WP3 to examine the quality of available data for variables common to multiple cohorts within the RECAP project, including looking at numbers of missing data items for whole populations (by country) and subcategories (e.g. sex, survival status, birth weight category) of participants. In parallel, we will seek to identify differences in data definitions for compound outcomes (for example, “severe neurodevelopmental disability”) between cohorts to facilitate investigation and interpretation of morbidity outcomes at 2-3 years of age.

Studies Included


Data from all births occurring between 22 and 26 completed weeks of gestation will be used. These will be analysed using four main populations: * All births – including live births, still births and terminations of pregnancy; * Fetuses alive at maternal admission to hospital and the onset of labour-monitoring (or the point at which a decision was made to perform Caesarean section). * Live births. * Babies admitted into neonatal intensive care. Consideration will be given to examining the populations excluding fetuses with life-threatening congenital anomalies. Exclusion of babies known to have serious congenital infections (e.g. rubella, cytomegalovirus) will also be considered.