Handling of risk-bearing drugs during pregnancy. Do we choose less risky alternatives?

The drug use of nearly 2,000 pregnant women was evaluated at the level of the individual patient for the drugs belonging to the Australian risk categories B3, C and D. The pattern of changes in the use of these drugs is studied in terms of women who discontinue (d), continue (c) or begin (b) using the drug during pregnancy. The ratios d/(c+b) and d/b were the highest for the drugs belonging to the high-risk groups and the lowest for drugs from the low-risk categories. This suggests a congruence between theoretical knowledge and daily practice. Patients who had already been using a drug for a long time before pregnancy, more frequently continued using that drug than patients who had been using the drug only incidentally before. The described daily dose for the riskful drugs was approximately 20% lower in patients who started to use a drug during pregnancy compared to those who continued drug use. The data from this analysis indicate that the prescribing physician is generally aware of the possible risks of drug use during pregnancy. The d/(b+c) and d/b ratios are shown to be a good measure of prescribing behaviour in relation to pregnancy and can be used to compare knowledge of theory and daily practice.