What type of medication may be restricted for pregnant women due to its estrogen content?

The correct answer is contraceptives, specifically those that contain estrogen, because they can pose risks during pregnancy. Estrogen-containing contraceptives are designed to prevent ovulation and menstrual cycles, but if taken during pregnancy, they can affect fetal development. There is a potential for complications such as increased risk of birth defects, clotting issues, and other adverse effects on both the mother and fetus.

In contrast, pain relievers, antibiotics, and anesthetics are generally categorized based on their safety during pregnancy and are used with caution if necessary. While some medications in these categories may also have restrictions or necessitate careful consideration, the issue regarding estrogen is particularly pertinent to contraceptive medications, making this the most appropriate choice.