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How CARIS works

CARIS aims to provide reliable data on congenital anomalies in Wales, which can be used to assess patterns of anomalies, including possible clusters and their causes and to inform the work of health services, including antenatal screening. 

Data collection commenced on 1 January 1998 and includes any affected pregnancy that ended from this date.

CARIS spends 25 years of helping to improve services - Find out more HERE
What is a congenital anomaly?

CARIS has defined an anomaly as involving structural, metabolic, endocrine, or genetic defects, present in the child / fetus at the end of pregnancy, even if not detected until after the birth. 

Welsh background

There are over 28,000 that pregnancies occur in Wales each year. Of these about three quarters are registered as live or still births. The remainder end in either spontaneous loss (miscarriage) before 24 weeks gestation or in an therapeutic termination of the pregnancy.

About three per cent (3%) of births take place at home. Wales currently has 12 consultant obstetric units and 9 midwifery led units, where the majority of births take place. For mothers living close to the English border, delivery often takes place in England, particularly Telford, Chester or Wirral hospitals. Delivery may also take place in England when a baby needs specalist care in the neonatal period, which may not be available in their area of Wales.  These include units in Bristol, Birmingham and Liverpool.

Sources of information

CARIS uses a multiple source reporting system to maximise case finding and to gain the fullest picture possible of complex cases with multiple anomalies.

Clinical reporting from midwives, obstetricians, paediatricians, and other specialists,  remains the most important source of information for CARIS. This provides a detailed description of the anomaly that is not available from other sources, especially for cases who:

  • die but do not have a post mortem
  • survive and have anomalies not requiring immediate specialist help or surgery

Electronic reporting aids the process of clinical reporting and can be used by emailing the CARIS Safehaven link or the E-Alert

Paper based warning cards and data collection forms are available.  Antenatal ultrasound reports of congenital anomaly are now reported electronically through RadIS as well as using warning cards.

Downloads from a number of databases are also invaluable for the register e.g. cytogenetics, paediatric cardiology and medical genetics. These are provided either quarterly or annually. In addition, inpatient data from the Patient Episode Database Wales (PEDW) provides important information on surgery, particularly that occurring in later infancy and childhood.

Data analyses
  • An annual download of data is taken from the CARIS database each summer. Further internal quality checks are undertaken (for example, to look for duplicate entries and to assess data completeness). Once these are complete, analyses are undertaken to update CARIS data tables and to monitor or further describe anomalies of interest or concern. Results are published on the CARIS website, in reports and are described in CARIS annual meetings around Wales each autumn.
  • Ad hoc data downloads and mini analyses are undertaken regularly throughout the year by the CARIS manager, in response to concerns about specific anomalies or other data requests. These analyses may involve using data that have not been subjected to the additional data quality checks applied to the annual download.