The development of magnetic resonance imaging (MRI) has made it possible to visualize various pathological conditions and changes, including those in pregnancy and lactation. Indications for MRI in this population refer to a number of maternal obstetric and non-obstetric causes, as well as those of the fetus, which are much rarer. Since this is a sensitive but not highly specific method, gadolinium-based contrast agents (GBCAs) are used. The use of GBCA is widespread, accounting for almost half of all MRI examinations, including those on pregnant and lactating women. Evidence of the effects of GBCA on nephrogenic systemic fibrosis formation, as well as knowledge of deposition, calls into question their safety when administered to a specified population, which requires a thoughtful benefit-risk assessment. The various studies discussed in this paper consider safety and theoretical ambiguities that primarily relate to the potentially harmful effects of GBCA on the fetus, as well as the possible its retention in breast milk. The results showed the passage of gadolinium through the placental barrier, with the concentrations in the fetus being minimal, and they were completely excreted within a few days. This also applied to various mother organs and breast milk. Despite the relatively small number of studies conducted on this topic, current recommendations approve the use of the least harmful, macrocyclic GBCA in situations where it is unavoidable, as well as the continuation of breastfeeding after its application.