Mom’s diet influences baby’s gender--study

Eating a high-fat diet around conception elevate the odds of a boy, whereas a low-fat diet with longer spells of fasting indicate a baby girl is more likely to be born.

Lead author of the study Dr Cheryl Rosenfeld of the University of Missouri stated, "High calorie diets generally favor birth of males over females, whereas low calorie diets tend to favor females over males.

"In humans and mice, food restriction and a suboptimal diet during the period around conception and early pregnancy also lead to a surfeit of daughters, most probably due to selective loss of male fetuses, the most vulnerable sex in the womb."

The diet/sex-ratio theory explored
In a bid to explore the impact of maternal diet for different genders the researchers conducted a study on pregnant mice fed on a very high-fat diet, a low-calorie diet or a normal diet.

Then they studied the pattern of activity of a large panel of genes in the placentas at 12.5 days of pregnancy.

The investigators noted that high- or low-fat diets had an effect on almost 2,000 genes in the developing fetus, including those involved in kidney function and smell.

The most striking difference was found in female fetal mice that were more sensitive to the mother’s eating habits, and their genes were more likely to be affected or altered.

The authors declared, “The expression of 1,972 genes was changed more than twofold in comparisons across diet. Female placentae demonstrated more striking alterations in gene expression in response to maternal diet than male placentae.

“Notably, each diet provided a distinctive signature of sexually dimorphic genes, with expression generally higher in genes from female placentae than those from male placentae.”

Reasons for link between diet and gender ambiguous
The scientists are unable to fathom the reason behind the impact of maternal diet on either sex ratio or gene expression.

However, it is evident that diet during pregnancy could have long-term health effects on children.

Both boys and girls are at different risks for conditions such as obesity or diabetes later in life depending on the mother’s food habits and her body condition while pregnant.

Authors state, “The reason why a maternal high-fat, low-carbohydrate diet favours survival of sons and a maternal low-fat, high-carbohydrate diet results in more daughters continues to elude us. The effect was such that the more women ate the more likely she was to have a boy.

“Women who had sons were also more likely to have eaten a higher quantity and wider range of nutrients including potassium, calcium and vitamins C, E and B12. They were also more likely to have eaten breakfast cereals.”

The details of the study are published in the Proceedings of the National Academy of Sciences.