The role and possible mechanism of nutritional factors on sex ratio of the fetus: A review article

Document Type : Review Article


1 M.Sc Student of Nutrition Sciences, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran.

2 PhD Student of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

3 Associate Professor, Department of Obstetrics and Gynecology, Women's Health Research Center, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran

4 Associate Professor, Department of Nutrition, Nutrition Biochemistry Research Center, School of Medicine, Mashhad University of Medical Science, Mashhad, Iran.


Introduction: The incidence of certain genetic diseases occurring in a certain sex as well as the variations of the sex ratio in some countries have led to an increased interest in sex determination. Different methods of sex determination are available, among which nutrition has been taken into consideration, since it doesn’t need any special equipment, cheapness, availability and ease of access. This study was performed with aim to investigate what dietary factors can affect the sex ratio and what are the possible mechanisms of their impact on the sex ratio.
Methods: To search the papers regarding the different factors affecting the sex ratio, without limiting the time, related keywords of BMI, Blood Glucose, Calcium, Calories, Diet, Estrogen, Fatty Acids, Female Sex Hormones, Follicle Stimulating Hormone, Luteal Hormone, Magnesium, Omega3, Omega6, Potassium, Progesterone, Sex Ratio, Sex Selection and Sodium were searched on PubMed and Google Scholar databases and the results from the most important entries were investigated in this study.
Results: In some studies, physical condition, type and calorie size of the mother’s diet, the blood glucose level, the types of ferry fatty acids in the diet and exclusive diets were considered as the effective factors influencing on the sex ratio.
Conclusion: The mechanism of dietary factors influencing on sex ratio is not exactly clear. However, since the articles have mentioned some nutritional factors affecting the sex ratio as the factors influencing sex hormone levels, so it is possible that one of the mechanisms of the effect of dietary factors on sex ratio is through their effect on sex hormones.


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