General presentation

The interactive EUROCAT prevalence charts and tables show the prevalence of 104 congenital anomaly (sub)groups. For details on the definition of the EUROCAT classification of congenital anomalies in subgroups see Chapter 3.3. of the EUROCAT Guide 1.5.

EUROCAT subgroups pool congenital anomalies together based on shared clinical characteristics and etiology. Only cases with major congenital anomalies, defined as structural changes that have significant medical, social or cosmetic consequences for the affected individual, are included in the subgroups. Cases with only minor anomalies are excluded (for details on which anomalies are excluded see Chapter 3.2. of the EUROCAT Guide 1.5).

The EUROCAT subgroups of congenital anomalies were updated in 2022/2023, based on advances in genetic diagnostic techniques, review of the literatures, data extractions from the JRC-EUROCAT Central Database and expertise from the EUROCAT Coding and Classification Committee. The new classification is in use for the prevalence tables since June 2022 and applies to all cases present in the JRC-EUROCAT Central Database.

Display rules

In order to comply with the provisions of the General Data Protection Regulation (2016/679, "GDPR") and to protect the privacy of individuals with congenital anomalies, the EUROCAT network implemented the following rules to display small numbers on its website:

  • Absolute numbers of cases are rounded to the nearest multiple of 10. This means that:
    • 0 indicates that between 0 and 4 cases are registered;
    • 10 indicates that between 5 and 14 cases are registered;
    • 20 indicates that between 15 and 24 cases are registered;
    • etc.
  • Prevalence rates are rounded to 0.5 per 10,000.
  • Proportions are rounded to the nearest 5%.
  • Live births and still births are gathered in a unique column.
  • In each given subgroup, proportions and prevalence rates are hidden if at least one type of births on the row is below 5 cases. When this happens, a “-“ is displayed, while a proportion/prevalence of 0 indicates that no case was registered for the selected criteria (centre, period of time, anomaly subgroup).
  • Finally, the total number of births – in the area covered by the selected registry or registries – is shown as a range of 20,000.
  • "n.d" is displayed when proportions cannot be calculated (0 case).

To get better estimates, we advise you to select several registries and/or several years, especially for rare malformations. In particular, please note that the display rules are not applied when selecting all (full) registries.

Finally, graphs have been removed when individual registries are selected, as many annual data are hidden, according to the above mentioned display rules.

In case you would need further results, please contact the JRC-EUROCAT central registry ( We will evaluate your request, based on the detailed background information you can provide.

Technical notes

1. Prevalence and 95% confidence intervals are per 10,000 births. Chapter 4 of the EUROCAT Guide 1.5 provides detailed information about the calculation and the interpretation of the prevalence.

2. The prevalence of non-genetic subgroups can also be shown excluding cases with additional genetic disorders by selecting “Excluding genetic conditions”. The Export raw data also allows to display both information (including and excluding genetic conditions).

3. In all tables: LB = live births; FD = fetal deaths from 20 weeks gestation, including stillbirths; TOPFA = termination of pregnancy for fetal anomaly following prenatal diagnosis.

4. Data from the most recent year is provisional as there is likely to be under-reporting as late diagnoses may not be included.

5. To help interpret the data, refer to the registries’ descriptions.

6. There are six EUROCAT subgroups of congenital anomalies with no ICD9 code (see Chapter 3.3. of the EUROCAT Guide 1.5), therefore tables based on a time period spanning pre-2005 and post-2005 years will not include data for years when registries were coding in ICD9.

7. The number of cases in each congenital anomaly subgroup is NOT the number of isolated cases. In particular the outcome, such as fetal deaths (FD) or terminations (TOPFA), for seemingly less severe anomalies may have occurred as the case had other more severe major anomalies.