Past, presence and future of the surveillance of the congenital anomalies
Date: 16.7.2010
Congenital anomalies monitoring systems and surveillance programs were created in many countries during the 20th century. Their main goal was to identify potential teratogenic threats that may affect the general population. Today these organizations have many new duties that should decrease incidences of congenital anomalies in newborns.
Congenital anomalies (or birth defects) are the disorders of prenatal development that are present at birth. Approximately 3-5 % of newborns are affected by some type of congenital anomaly. The clinical significance of these anomalies differs from mild cosmetic defects to lethal structural malformations.
Congenital anomalies are not the disorders of the modern era - historical cases of people with congenital anomalies are well known (from both historical writings and archaeological findings). However, the causes of these anomalies remained unknown for long centuries (for example - in medieval times - it was believed that these anomalies result from demonic powers).
In the 19th and 20th century the situation changed a lot, because the real causes of these anomalies were discovered. These factors, known as teratogens, include biological (viral diseases), physical (radiation) and chemical (chemicals, drugs) factors. Some types of congenital anomalies can also have a genetic cause (chromosomal abnormalities, mutations in DNA).
There were several incidents and affairs in the 20th century, because of them the need of incidence monitoring of the congenital anomalies increased rapidly. The worst (and also the most "famous") was the thalidomide affair.
In the late 50ties and early 60ties of the 20th century, thousands of children worldwide were born with severe malformations. With some delay the scientists found out, that mothers of these children had had one thing in common - they had used the substance thalidomide during the pregnancy. The thalidomide was originally developed as a tranquiliser or sedative and one of its indications was the morning sickness of the pregnant women.
Regrettably, the thalidomide acts as a potent teratogen and can cause several types of anomalies (typically reduction malformations of the extremities). However, the increase of incidence of these types of anomalies remained undetected for long months and even years, because there were quite no systems or registries able to detect this increase on national or even international level.
The thalidomide affair was one of the reasons (but not the only one) to set up congenital anomalies monitoring programmes in many countries of the world. For example, the surveillance program of congenital anomalies in former Czechoslovakia started in 1964. Some of these registries were population-based (covering all births in the whole country) and some of them were based on the local data (covering the births in specific region or in specific hospital). However, there was still need to monitor the incidences on the international level.
So, in 1974 the ICBDMS (International Clearinghouse for Birth Defects Monitoring Systems) organization was set up in Helsinki. The main duty was to improve the communication and coordination among the member registries. The data started to be analyzed centrally - in regular intervals so any new teratogenic threats could be identified very quickly.
This opened the way to large international studies - based on the data from more countries. Today, the ICBDSR (the name changed in 2004 to International Clearinghouse for Birth Defects Surveillance and Research) organization has 47 member registries and organizations worldwide. On the European level another organization - EUROCAT was founded in 1979. This organization associates registries and surveillance programs from Europe.
Today, the duties of the national and international congenital anomalies surveillance organizations became more complex. The simple analyzing of incidences - that used to be the main duty - is today only one of many duties. Hundreds of new medicaments, air and water pollution, obesity or assisted reproduction methods - these are factors that should be also analyzed and monitored carefully.
We have spoken about the epidemiological work so far. But one of the new duties is also the active work for the public health. In many countries, the preventive programs - focused on primary prevention of congenital anomalies were set up. These activities are often coordinated by the congenital anomalies surveillance organizations (again on both national and international level).
The new issued recommendations include tips for nutrition, smoking policy, body weight, medicaments usage etc. In future, the effect of these preventive programs will be analyzed and the recommendations will be adjusted accordingly - in order to improve their effect.
The oldest congenital anomalies monitoring systems exist for more than 50 years today. Their duties and activities changed a lot during this time. But the main duty remains the same - to detect all potential teratogenic factors (new drugs, chemicals, materials or technologies) as soon as possible and to ensure, that there will not be any new "thalidomide affair" again.
Autor: Antonín Šípek
References:
1) Šípek, A., Gregor, V., Horáček, J., Mazánková, V., Langhammer, P. and Šípek, A. jr.: History and present of registration of congenital anomalies in the Czech Republic (in Czech). Čas. Lék. čes., 2009, 148, pp. 505-509.
2) National Registry of Congenital Anomalies of the Czech Republic
(website - http://www.vrozene-vady.cz/)
3) International Clearinghouse for Birth Defects Monitoring Systems
(website -http://www.icbdsr.org/)
4) European Surveillance of Congenital Anomalies
(website - http://www.eurocat-network.eu/)
