Clinical practice indicates that the lack of evidence database on the effect of drugs and biological products on the course of pregnancy presents women and doctors in charge with a difficult dilemma, when prescription of the drugs, which have not undergone clinical studies, renders correct dosage and account of potential fetus-associated effects impossible. On the other hand, refusal to use drugs during pregnancy may result in harm to health not only of mothers, but also of their unborn r newborn children caused by the disease-associated pathological alterations [1,2]. Risk/benefit balance of drug therapy is not always clear both for a mother and her fetus; it is circumstantial and specific in every woman [3]. In order to minimize embryofetal risk, it is necessary to identify and avoid using nonessential drugs, regulate dose, frequency and way of administration of the drug and duration of the essential treatment. It ought to be mentioned, though, that development of new drugs for treating pregnancy-associated pathological conditions present scientists with the challenges that only rarely occur in other populations. Any drug interventions awake in women fear of pregnancy-and labor-associated complications. This fact complicates clinical studies of drugs, because any risk assumption renders such clinical studies unacceptable for pregnant women. On the other hand, there is an obvious need in validating drug efficacy and safety data obtained in the clinical studies involving different populations of patients with respect to pregnant women, as their bodies undergo a range of functional changes during gestation [4]. Additional studies aimed at identifying the factors determining pregnancy-associated changes of pharmacokinetics (PK) and pharmacodynamics (PD) of drugs are required for women not to be barred from achievements of the modern pharmacotherapy. There is also an ethical dilemma of involving this particularly sensitive category of patients in randomized controlled studies of safe and efficacy of drugs [5]. At the same time, new discipline -obstetric-fetal pharmacology -may form the basis of extensive study of gestational use of drugs [6]. In order to enable pharmacological studies involving pregnant women, a model, which