History and Funding
The Barcelona Birth Defects Registry (Registre de Defectes Congènits de Barcelona –REDCB-) was initiated in 1990 and reached a population-based status by 1992, when it became a member of the EUROCAT. The REDCB is part of the Service of Health Information Systems (Servei de Sistemes d’Informació Sanitaria) in the Public Health Agency of Barcelona (Agència de Salut Pública de Barcelona). It is funded by Regional (Generalitat de Catalunya) and Local (Ajuntament de Barcelona) Administrations.
Population Coverage
The REDCB is population-based and covers pregnancies of women resident in Barcelona city ending in live or stillborn babies of 22+ weeks of gestation or in induced abortions (IA) due to prenatal detection of birth defects (BD), i.e., the registry do not include BD in spontaneous abortions –less than 22 weeks of gestation- or IA not due to prenatal detection of BD.
Some 3% of residents’ newborns occur at maternity units out of the city limits. The REDCB controls 50% of these newborns (1.5%), delivering in a hospital near the city. Since Barcelona city is a pole of attraction for at risk pregnancies, the remaining 1.5% of newborns not controlled by the registry probably provides less than 1% of cases.
Currently (2008) the REDCB covers about 14,500 births annually. In the last 5 years, the number of births has increased from about 12,500, mainly due to a higher fertility rate among immigrant women of developing countries coming to the city.
Sources of Ascertainment
General information on cases and controls as well as clinical information on cases is collected using questionnaires specifically made for the Registry. An interview with the mother is the main source of general information. Delivery units, paediatric departments, cytogenetic laboratories, pathology departments, prenatal diagnosis units, paediatric cardiology services, etc. are the main sources of clinical information.
The registry has direct access to some cytogenetic labs, but not to all. Some of the collaborating labs send their data by e-mail, but for most of them, registry staff personally go to collect the case information. Direct access to cytogenetic laboratories covers only part of our population.
Paediatric cardiology centres covering part of the registry population supply systematic case lists and diagnostic details to the registry.
Maximum Age at Diagnosis
Up to 3 days of age. When a suspicion of BD exists, follow-up is made until a diagnosis or normality is stated. This affects mainly BD as CHD.
Terminations of Pregnancy for Fetal Anomaly (TOPFA)
IA after prenatal detection of BD is legal in Spain until 22 weeks of gestation. A probable future modification in the Spanish IA law will affect BD: some foetuses with major BD detected in the 3rd trimester of pregnancy (i.e., after 22 weeks) could be induced for abortion.
Case definition
Foetuses or newborns with at least 1 major or 2+ minor anatomical BD or with unbalanced chromosomal anomalies. The follow-up period is 2-3 days after delivery. Due in part to this short follow-up period, poor ascertainment exists for BD as mild hypospadias, some cardiovascular defects and others anomalies of internal organs not detected using prenatal ultrasounds.
The ascertainment of unbalanced chromosomal anomalies without neonatal anatomical defects (as some sexual chromosome anomalies like XXX, XXY, XYY, etc.) is never complete and depends on the rate of karyotyped pregnancies.
Controls Selection
A random sample (not case-matched) of about 2% of the newborns expected in each maternity unit is selected as controls.
Denominators and Controls Information
Background data on births are available from birth certificates and the Barcelona Perinatal Mortality Registry.
Ethics & Consent
The registry is located in a health authority setting (Barcelona Public Health Agency). Parental consent is asked for during interview with the mothers of cases and controls.
Address for Further Information
Servei de Sistemes d'Informació Sanitària (SESIS)
Agencia de Salut Pública de Barcelona (ASPB)
Pl. Lesseps, 1
08023 Barcelona, Spain
Last updated: September 2010