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...
Main Authors: | , , |
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Format: | Journal article |
Language: | English |
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2008
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_version_ | 1797101753237241856 |
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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'. |
first_indexed | 2024-03-07T05:56:20Z |
format | Journal article |
id | oxford-uuid:eaa44334-6027-4200-8bb2-26686d0adb81 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-07T05:56:20Z |
publishDate | 2008 |
record_format | dspace |
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 |
work_keys_str_mv | AT mathewsf youarewhatyourmothereatsevidenceformaternalpreconceptiondietinfluencingfoetalsexinhumans AT johnsonp youarewhatyourmothereatsevidenceformaternalpreconceptiondietinfluencingfoetalsexinhumans AT neilh youarewhatyourmothereatsevidenceformaternalpreconceptiondietinfluencingfoetalsexinhumans |