During pregnancy, many physiological and metabolic alterations occur to support the requirements of the developing fetus. Alterations associated with the respiratory, cardiovascular, hematological, urinary, and gastrointestinal systems (GIS) may result in pregnancy-related disorders and may change the pharmacokinetic or pharmacodynamic characteristics of received drugs; the pharmacokinetic phase of drugs include their absorption, distribution, metabolism, and excretion. This involves reduced plasma albumin concentrations, increased cardiac output, increased gastric pH, reduced intestinal motility, and increased glomerular filtration rate (GFR). Drug-nutrient interactions are defined as physicochemical, physiological, and physiopathological interactions between a drug and a nutrient as well as between a drug and food, multiple nutrients, other dietary components, or nutritional status of the body. Understanding the impact of these changes on drug pharmacokinetic properties and food, drug-nutrient interactions are essential to ensure/optimize maternal health and fetal development. As a consequence, drug-nutrient interactions over the course of the pharmacological treatment of complications and disease during pregnancy should be considered. The purpose of this review is to summarize physiological changes during pregnancy and their effects on pharmacokinetic properties and to evaluate potential food, nutrient, and drug interactions.