Microplastics (MPs) and nanoplastics (NPs) have attracted significant attention due to their ubiquitous environmental presence and unique physical and chemical properties. MPs refer to plastic particles with sizes smaller than 5 micrometers, while NPs are particles with sizes smaller than 100 nanometers. Both types exist in the environment, can sediment, traverse biological barriers, and transport chemicals. Confirming their presence in human feces, meconium, and placenta underscores their potential impact on human health. These particles can enter the human body through inhalation, food and water consumption, mucus, skin, and ingestion of microplastic products. They can negatively affect the health of children, infants, and pregnant women. This can be particularly concerning and damaging to this group of individuals due to their immature immune systems and developing organs, and can lead to further harm. Pregnancy, infancy, and childhood are sensitive periods for environmental exposure. Therefore, further research on the effects of microplastics on children, infants, and pregnant women is necessary, and appropriate policies should be developed to reduce plastic use and protect the health of these groups.