The natural inclination of patients with rheumatic diseases wishing to become pregnant or to breast feed will be to take as few medications as possible. The guidelines outlined above can be used to balance the risk of drug effect on the fetus or neonate with the risk of inducing a flare in disease activity by stopping the drug. Although there are situations where no information on drug behaviour during pregnancy or lactation exists, some guidelines can be developed from a knowledge of the drug's inherent metabolism. In the majority of the rheumatic diseases, disease activity can be reduced to a minimum using the smallest possible dose of drugs known to be safe in pregnancy and lactation, thus providing minimum risk to mother, fetus and neonate.