Maternal medication use during pregnancy is explored extensively, as it may cause birth defects. This study aimed to evaluate the validity of recorded medication use in the Medical Birth Registry of Norway (MBRN).
This study was based on the nationwide population-based registries, the MBRN and the Norwegian Prescription Database (NorPD). These registries were linked using a unique 11-digit identification number. The sensitivity, specificity and positive predictive value (PPV) of recorded medication use in MBRN were computed using data from NorPD as the reference.
Among the 163,678 pregnancies included in our study, the sensitivity for total drug use during pregnancy was calculated to be 32% and PPV was 82%. When we looked at the use of medication during the whole pregnancy, the sensitivities of drug registration for the main groups in the Anatomical Therapeutic Chemical (ATC)-classification varied from 50% (ATC group H) to 2% (ATC group S).
The medication use recorded in MBRN is poor compared with prescribed medicines registered in NorPD. There was a substantial difference between the different ATC codes regarding the sensitivity of MBRN in the registration of medication use during pregnancy.