Materials and Methods: A systematic literature search in English was performed with pre-determined keywords on preconception maternal diet, maternal nutritional status, fetal sex, and sex ratio in international electronic databases (i.e., ISI Web of Knowledge, PubMed, Cochrane Library, and Scopus) with no time limitation. Reviews, letters to the editors, commentaries, editorials, experts? opinions, and publications without available electronic full texts were excluded.

Results: Fifteen studies fulfilled the criteria and were categorized into 2 groups; the first group included publications on maternal nutritional status. Despite the heterogeneity of the articles, it was assumed that the nutritional status did not affect the sex ratio at birth except for malnutrition. In the second group which included publications on the maternal diet, results illustrated a relation between a diet with high sodium and potassium intake and male gender. Besides, high magnesium and calcium intake were found to be related to female foetus.

Conclusions: Based on the results obtained, it can be concluded that there are not enough publications regarding the effect of maternal nutrition on the sex of child in the literature. Accordingly, more researches are warranted.