Does Maternal Nutrition Have Any Impact on Sex Ratio at Birth in Animal and Human Studies?

Abstract

The sex ratio at birth (SRB) is the ratio of male-to-female births. This ratio is slightly skewed toward males (about 105 males to 100 females). However, several studies mostly in experimental animals have raised the question of whether the sex ratio in humans may be modified by certain nutritional and nonnutritional factors. The aim of this literature review is to explore the influence of maternal nutritional factors on sex ratio at birth in various animals and humans. We used Google Scholar, Research Gate, ProQuest, Scopus, Cochrane, and PubMed databases to collect appropriate articles for the review without limiting the publication period. Of the different nutritional approaches in animals the most frequent manipulations are controlling the energy intake and, to a lesser extent, the composition of the diet in terms of macronutrients and micronutrients is most likely to influence the sex ratio at birth in animals. The data on these factors affecting sex ratio at birth are sparse and offer little promise of influencing sex at birth in humans.