The quality and the accuracy of codes for terminations of
pregnancy for fetal anomalies recorded in hospital
databases in three countries in northern Europe
Data from hospital databases may be used for registration and surveillance of cases with congenital anomalies. Some of these cases are diagnosed prenatally followed by termination of the pregnancy. It is important that all birth outcomes are included in the surveillance of congenital anomalies and in studies on possible teratogenic risks of pregnancy exposures. The aim of this EUROlinkCAT study was to evaluate the quality and the accuracy of codes identifying pregnancies terminated for severe fetal anomalies in hospital databases. Data for the study was only available from three EUROCAT registries in Northern Europe: Finland (birth years 2010-2014), Funen in Denmark (birth years 2005-2014) and Northern Netherlands (birth years 2013-2014. All cases with congenital anomalies in these three registries registered as termination of pregnancy were linked to hospital databases using maternal IDs. There were 2,114 cases over the study period and 2,096 (99%) of these pregnancies were identified in the hospital databases. An end of pregnancy code was present for 91% of the cases and a code for a congenital anomaly was present for 82% (with some differences across registries). The proportion of cases with a code for a specific congenital anomaly was less than 50% for cases with a structural anomaly (range 0-50%) and 70% for cases with a chromosomal anomaly.
Hospital databases have limited information or codes to identify terminations of pregnancy for specific anomalies and the data are not detailed enough for surveillance of congenital anomalies or for studies analysing pregnancy exposures and risk of congenital anomalies. However, hospital data may be used to identify the occurrence of a termination of pregnancy to enable more detailed information to be obtained from the medical records.