Introduction: Good nutrition is one of the most important factors in a healthy pregnancy, which is related to mother’s health, rate of pregnancy complaints, fetal growth and the delivery complications. In recent decades, the use of alternative and complementary medicine has increased considerably. Using herbal products in order to avoid the chemical drugs side effects is increasing specially among pregnant women. However arbitrary use of these herbs without considering their side effects would endanger the health of the mother and the fetus.

Methods: Reviewing available references from Traditional Iranian Medicine on pregnancy as well as the books, papers and case reports from the conventional medicine about using herbs during pregnancy, we made a comparative study in this field that is presented.

Results: Principles of nutrition during pregnancy in the conventional medicine resources are based on micro and macronutrients and calorie intake. The complications due to lack of the nutrients or poor calorie intake in pregnant women is discussed in the nutrition text books in detail, but the use of herbal supplements is not well explained reflecting the limited research in this field. In Iranian traditional medicine resources healthy life style during pregnancy including the use of food and herbal drugs is well documented. It is recommended for pregnant women to use ‘Saleh-al-kimus’, subtle and mild foods and avoid to use special herbs which are abortogenic or teratogenic.

Conclusion: Despite the benefits of herbal products, misuse of them may lead to severe complications so increasing the knowledge of physicians and pregnant women about the side effects of herbal drugs during pregnancy considering the information of traditional medicine resources, ensures mother and fetus health and improves public health.