Congenital Anomaly Register and Information Service (CARIS)

Data Providing Organisation:
Congenital Anomaly Register & Information Service for Wales

Data Providing Type:
Registry data



CARIS aims to collect reliable data about congenital anomalies that can then be used to help:

  • build up and monitor the picture of congenital anomalies in Wales
  • assess interventions intended to help prevent or detect congenital anomalies
  • plan and co-ordinate provision of health services for affected babies and children
  • assess possible clusters of birth defects and their causes

CARIS collects information about any fetus or baby who has or is suspected of having a congenital anomaly and whose mother is normally resident in Wales at time of birth. It includes babies in whom anomalies are diagnosed at any time from conception to the end of the first year of life. Data collection commenced on 1st January 1998 and includes any baby where pregnancy ended after this date.

Data Collection Method

CARIS uses a multi-source data collection method using a wide range of sources within the NHS. This ranges from antenatal ultrasound, clinical letters, post-mortems and laboratory results. CARIS also accesses a number of databases including SHIRE (Medical Genetics database), PEDW, NCCHD, Paediatric Cardiology database. Medical records are accessed to confirm, validate and add further details to the information already collected.

Data Highlights

Due to the nature of this dataset linkage based on the babies is challenging. This is because many pregnancies (approximately 20% of the total) end in fetal loss or termination. However, linkage based on the mother can be performed.

It is important to note that not all babies included in the CARIS dataset will be born with congenital anomaly, therefore it is important to check the value of the suspected variable in the anomaly table.

In 2012 a co-morbidity table was added to the database to better separate congenital anomalies from other significant conditions.

CARIS release the dataset annually and the SAIL anonymised version is updated accordingly.

Access Requirements

As a restricted dataset, that requires the agreement of the data provider in addition to our standard Information Governance procedure.

More Information

See the CARIS website for more information and to view their published reports.


Approx 1500 babies per year

Data Level

Individual person

Data Years

1998 – 2011

SAIL Schema