You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.

Facultative adjustment of sex ratios by mothers occurs in some animals, and has been linked to resource availability. In mammals, the search for consistent patterns is complicated by variations in mating systems, social hierarchies and litter sizes. Humans have low fecundity, high maternal investmen...

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Main Authors: Mathews, F, Johnson, P, Neil, H
Format: Journal article
Language:English
Published: 2008
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author Mathews, F
Johnson, P
Neil, H
author_facet Mathews, F
Johnson, P
Neil, H
author_sort Mathews, F
collection OXFORD
description Facultative adjustment of sex ratios by mothers occurs in some animals, and has been linked to resource availability. In mammals, the search for consistent patterns is complicated by variations in mating systems, social hierarchies and litter sizes. Humans have low fecundity, high maternal investment and a potentially high differential between the numbers of offspring produced by sons and daughters: these conditions should favour the evolution of facultative sex ratio variation. Yet little is known of natural mechanisms of sex allocation in humans. Here, using data from 740 British women who were unaware of their foetus's gender, we show that foetal sex is associated with maternal diet at conception. Fifty six per cent of women in the highest third of preconceptional energy intake bore boys, compared with 45% in the lowest third. Intakes during pregnancy were not associated with sex, suggesting that the foetus does not manipulate maternal diet. Our results support hypotheses predicting investment in costly male offspring when resources are plentiful. Dietary changes may therefore explain the falling proportion of male births in industrialized countries. The results are relevant to the current debate about the artificial selection of offspring sex in fertility treatment and commercial 'gender clinics'.
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spelling oxford-uuid:eaa44334-6027-4200-8bb2-26686d0adb812022-03-27T11:03:43ZYou are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:eaa44334-6027-4200-8bb2-26686d0adb81EnglishSymplectic Elements at Oxford2008Mathews, FJohnson, PNeil, HFacultative adjustment of sex ratios by mothers occurs in some animals, and has been linked to resource availability. In mammals, the search for consistent patterns is complicated by variations in mating systems, social hierarchies and litter sizes. Humans have low fecundity, high maternal investment and a potentially high differential between the numbers of offspring produced by sons and daughters: these conditions should favour the evolution of facultative sex ratio variation. Yet little is known of natural mechanisms of sex allocation in humans. Here, using data from 740 British women who were unaware of their foetus's gender, we show that foetal sex is associated with maternal diet at conception. Fifty six per cent of women in the highest third of preconceptional energy intake bore boys, compared with 45% in the lowest third. Intakes during pregnancy were not associated with sex, suggesting that the foetus does not manipulate maternal diet. Our results support hypotheses predicting investment in costly male offspring when resources are plentiful. Dietary changes may therefore explain the falling proportion of male births in industrialized countries. The results are relevant to the current debate about the artificial selection of offspring sex in fertility treatment and commercial 'gender clinics'.
spellingShingle Mathews, F
Johnson, P
Neil, H
You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title_full You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title_fullStr You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title_full_unstemmed You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title_short You are what your mother eats: evidence for maternal preconception diet influencing foetal sex in humans.
title_sort you are what your mother eats evidence for maternal preconception diet influencing foetal sex in humans
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