Eurocat Website Data on Prenatal Detection Rates of Congenital Anomalies

Abstract

The EUROCAT website www.eurocat-network.eu publishes prenatal detection rates for major congenital anomalies using data from European population-based congenital anomaly registers, covering 28% of the EU population as well as non-EU countries. Data are updated annually. This information can be useful for comparative purposes to clinicians and public health service managers involved in the antenatal care of pregnant women as well as those interested in perinatal epidemiology.

Over the past 25 years, there have been major changes in prenatal diagnosis of congenital anomalies. Today structural malformations of most organ systems are detectable by ultrasound performed during pregnancy. This may be followed by a choice to terminate an affected pregnancy. The prenatal detection of congenital heart defects and some other anomalies have an increasingly important role in planning for and delivering effective postnatal treatment, as well as the provision of counselling and other services for affected women. Clinicians and health service managers need up-to-date information on the proportion of congenital anomalies prenatally detected, and how this relates to screening policy, in order to compare and evaluate their local detection rates. It is important that this information is population-based, and not based only on the prenatal detection rates provided by specialist tertiary centres with high levels of expertise, the most up-to-date screening methods, and often serving selected groups of higher-risk women.

EUROCAT is a European Network for Surveillance of Congenital Anomalies. ¹ The network started back in 1980 and now includes over 40 registries in 20 countries and covers 28% of all births in the European Union as well as other European countries. The registries use multiple sources of information to ascertain cases such as hospital records, birth and death certificates, post mortem examination reports, and include information about livebirths (LB), fetal deaths (FD) with gestational age ≥20 weeks and terminations of pregnancy (TOPFA) after prenatal diagnosis of malformations. All major structural malformations, syndromes and chromosomal anomalies are included in the database. Cases are classified in specified subgroups according to the malformation codes given at local level. Prevalence data on individual malformations by type of birth can be found on the website at http://www.eurocat-network.eu/ACCESSPREVALENCEDATA/PrevalenceTables. For all full member registries 2003-2007 the prevalence of all major anomalies was 2.37% and for non-chromosomal major anomalies overall prevalence was 2.01% (Website January 2010). Of the 76,216 cases with congenital anomalies reported in 2003-2007 13,410 (17.6%) were TOPFA.

EUROCAT publishes data on prenatal detection rate on the website in three tables for the most recent 5-year period, which is updated annually: http://www.eurocat-network.eu/PRENATALSCREENINGAndDIAGNOSIS/PrenatalDetection Rates. An extract of these data is shown in Table 1: the prenatal detection rate of 6 major malformations and Down's syndrome for 2003-2007 in 18 registries with high quality data on time of diagnosis. Prenatal detection rates for these seven anomalies are also available by individual registry on the website. Another table on the website shows the gestational age distributions for all congenital anomalies combined resulting in TOPFA by registry. The website data are updated annually. The list of anomalies published on the website will soon be extended.

Table 1

Prenatal diagnosis of 7 selected major congenital anomalies in 17 EUROCAT registries 2003-2007

Congenital anomaly	Total cases	Cases prenatally diagnosed (% of total cases)
Anencephalus and similar *	661	635 (96%)
Spina bifida *	1283	871 (68%)
Transposition of great vessels *	800	263 (33%)
Hypoplastic left heart *	609	398 (65%)
Gastroschisis *	571	476 (83%)
Bilateral renal agenesis and Potter sequence *	245	200 (82%)
Down's syndrome	5032	2683 (53%)

*

Non-chromosomal cases only

The prenatal detection rate is related to the policy of prenatal screening in the actual region or country. ² Reports of the prenatal screening policies and the laws on TOPFA in 13 European countries for 2005 and 2009 are available at the EUROCAT website (http://www.eurocat-network.eu/PRENATALSCREENINGAndDIAGNOSIS/GeneralInformation/PublicationsonPrenatalDiagnosis) as well as a list of collaborative publications relating to prenatal screening and specific congenital anomalies.