Improvement of drug exposure data in a registration of congenital anomalies. Pilot-study: Pharmacist and mother as sources for drug exposure data during pregnancy

We examined the possibilities of improving the retrospective collection of data an drug use during pregnancy. The European Registration of Congenital Anomalies (EUROCAT) has registered information on maternal drug exposure in the northern Netherlands through a question on the notification form for t he registration of birth defects, filled out by physicians or midwives sinc e 1981. Furthermore, hospital records are used and general practitioners ar e asked to add information on drug use. The present pilot study used pharma cy records and maternal questionnaires as well as maternal interview data t o complete the data on drug exposure in the EUROCAT registration. Combined information from pharmacies, questionnaires, and interviews with the mother were used as the reference standard. Pharmacy records provided detailed da ta on 57% of drugs used (prescription drugs, mainly). Mothers were able to report 76% of drug groups used, but when only data on the exact name of the drug were studied, this figure was 52%. Of the drugs dispensed by the phar macy, 6% were not used (false positives). We conclude that pharmacy records and maternal interviews are both indispensable sources of information on m aternal drug exposure that provide much added value. (C) 1999 Wiley-Liss, I nc.