It is a major clinical and public health problem that there is no clear strategy as to how we best make use of information obtained when pregnant women take drugs. For this reason, some pregnant women are not treated as they should be and some are given drugs they should not use. We suggest a monitoring system that combines some of the available datasets in Europe. Using these sources as a starting point, one can develop a system that has sufficient power to detect even rare diseases like congenital malformations and sufficient diversity to detect several possible outcomes from spontaneous abortions to childhood disorders. We also suggest that case-crossover designs should be used in case-control monitoring systems that carry a high risk of recall bias. These considerations are based upon our results from a European Union-funded concerted action called EuroMaP (Medicine and Pregnancy).