Registration of drug use in a birth defect monitoring system: a priority worthy of emphasis!

Abstract

This article examines sources of information on drug use during pregnancy in the northeastern part of The Netherlands, comparing data from a congenital anomalies registry and figures obtained from community pharmacy records for a drug utilization study. Physicians and midwives report to the congenital anomalies registry on a voluntary basis. A limited quantity of exposure data is registered. According to the congenital anomalies registry, drug use during pregnancy is significantly less than it is according to the drug utilization study in the same area, suggesting that the former obtains incomplete data.For anomalies occurring spontaneously in a relatively high frequency, any link between a small further increase in the frequency of these anomalies and the maternal use of certain drugs is likely to go undetected if one monitors only the frequency of these anomalies, the increase being rendered inconspicuous by spontaneous variations. Routine monitoring of drug use in association with congenital anomalies will be needed if such links are to be profiled. Preferably, a complete and correct registration of all drug use should be assured, from three months before conception to the time of delivery.Data retrieved from the records of community pharmacies on the use of prescription drugs, complemented by data on hospital drug use and information from the women themselves on their self-medication is likely to produce a relatively complete picture of drug utilization for the purpose of a register of congenital anomalies.