Monitoring Congenital Anomalies: A Rigorous Methodology

To monitor congenital anomalies, Santé publique France coordinates a network of six registries covering 19% of births in France and contributes to their funding.

As part of its mandate, the Rhône-Alpes Birth Defects Registry (REMERA) notified the agency of a suspected cluster of 7 cases in the Ain department. Santé publique France systematically reviews these reports using a standardized protocol to determine whether the cluster is due to chance or not and to identify any potential common exposures. The process is as follows:

• An initial verification is conducted to confirm that the cases are indeed identical and share the same clinical definition;

• Then, the frequency of the malformation in the study area is compared to that across the entire country to verify whether or not there is an excess of cases.

• In addition to this statistical analysis, the agency is conducting a survey with the registry among the mothers of each reported case, asking them about their lifestyle habits during pregnancy and particularly during the first trimester. The objective is to identify any potential common exposures among these cases (medication use, environmental exposure, etc.).

Currently, following the investigation of the 7 cases reported in the Ain department born between 2009 and 2014, the statistical analysis does not indicate an excess of cases compared to the national average, and Santé publique France has not identified a common exposure linked to the occurrence of these malformations. The absence of a hypothesis regarding a possible common cause does not allow for the direction of further investigations.

The Agency also conducted similar investigations into two reports of upper limb agenesis in Loire-Atlantique (3 cases born between 2007 and 2008) and in Brittany (4 cases born between 2011 and 2013). For Loire-Atlantique and Brittany, the investigation concluded that there was an excess of cases. However, no common exposure was identified for the clustered cases in these two regions.

In this context, the Agency, together with the French registry network, is paying close attention to the occurrence of new cases in these regions and throughout the rest of France.

Surveillance of congenital anomalies: a system to be strengthened

The REMERA congenital malformations registry in Rhône-Alpes is one of six congenital malformations registries in France that collect data on these morphological anomalies and one of four registries in mainland France. It serves as an epidemiological surveillance tool for public health.

The surveillance of congenital malformations and related investigations are particularly complex, notably due to the rarity of these events. In response to a request from the Directorate General for Health, Santé publique France, together with the ANSM, proposed the creation of a federation of the six registries based on a common operational framework, as well as their further development, notably through linkage with data from the National Health Data System [SNDS]. The report is available on the Santé publique France website. Discussions are currently underway with the Directorate General for Health based on this report.

Learn more

• Congenital anomalies linked to drug and environmental exposures

• Investigation of a report of forearm agenesis in a municipality in Morbihan

• Investigation of a suspected spatio-temporal cluster of congenital malformations in the department of Ain

• Investigation of a spatio-temporal cluster of congenital malformations in a municipality in Loire-Atlantique