Final answer:
The class of reproductive drug that can be dangerous to pregnant females is estrogens. Estrogens are crucial for many reproductive functions but can pose risks if extra amounts are taken during pregnancy.
Step-by-step explanation:
The class of reproductive drug that can be potentially dangerous to pregnant females is estrogens. Estrogens are a class of predominantly female sex hormones that are important for the development and growth of the female reproductive tract, the regulation of the female reproductive cycle, and the maintenance of pregnancy. However, during pregnancy, exposure to additional estrogens can be harmful. Estrogens influence the endocrine system, which includes cells, tissues, and organs that secrete substances directly to target tissues via glandular ducts. Synthetic estrogens, such as those found in certain types of birth control, can carry risks for pregnant women, including the potential for weight gain and an increased chance of forming blood clots.