World Health Organization recommended exclusive breastfeeding as an economic and valuable method for protecting infant’s health during the life. It provides unique biologic and emotional effects for both mother and infant (
1,
2). Exclusive breastfeeding means that infant is fed only with breast milk without any other liquids or solid food and this definition does not include vitamins, minerals and medicines (
1). Malnutrition in the first year of life is the reason of two-third of deaths in fewer than five years old children in the world. Exclusive breastfeeding in first six months of life and continuing with complementary nourishment, decreases malnutrition and as a result decreases mortality of fewer than five years old children (
3,
4). Breastfeeding immediately after birth empowers infant’s immune system and reduces the risk of mortality up to 20%. The risk of morality in infants who are not exclusively breastfed is 14 times more than those exclusively breastfed (
5). Maternal advantages of breastfeeding include more rapid return to pre-pregnancy weight, decreased risk of type 2 diabetes, osteoporosis, post-delivery depression and breast and ovarian cancer (
6). According to the UNISEF reports in 2013, only 39% of infants younger than six months were exclusively breastfed in the world (
5). In Iran, 27.7% of infants aged six months were exclusively breastfed, while in those aged four months it was 56.8% (
7).The average age of weaning infants in Iran has been reported to be 3.2 months, which is different from 2.4 to 3.7 months in various places. Physicians recommendation is the most common reason for discontinuing exclusive breastfeeding (54%), which has been reported similar in urban and rural areas. Breast milk insufficiency, family and relatives recommendation, infant’s cry, and without any special purpose are other reasons (
8). Breast milk insufficiency is one of mothers’ main reasons to stop breastfeeding in the first six to eight weeks after birth (
9). Using Galactogogues is recommended to resolve this problem. Galactogogues are some substances or medicines that initiate, enhance and maintain milk production (
10,
11). About 43% of Norwegian women and 15% of American women use herbal galactogogues (
12). Fennel is a herb with galactogogues property. Scientific name of Fennel is Foeniculum vulgare, which belongs to the Umbelliferae family. The root, leaf, fruit and seed of Fennel are used (
13,
14). This plant contains comphen, Fencho and Anethol essences. About 60% of oil seed essence is consisted of Anethol. It seems that Fennel galactogogues mechanism results from Estrogenic and Phyto-estrogenic properties of Anethol and its polymers such as Di-Anethol and Photo-Anethol. Phyto-estrogens due to their structural similarity to estrogens can attach to α and β Estrogens’ receptors to exert estrogenic properties (
15-
17).
Performed studies related to Fennel’s galactogogues property are limited and have contradictory results. Since now no study has been performed to evaluate the effect of fennel on infant growth parameters, number of wet diapers in a day, frequency of defecation and infant breastfeeding times. Regarding the fact that this plant is local, cheap and available in Iran, this study was performed for the first time to evaluate the effect of fennel on breast milk sufficiency signs and infant growth parameters.