BACKGROUND: A recent study focusing on dietary predictors of nausea and vomiting in pregnancy (NVP) found that women with higher levels of partner support, and those who had used oral contraception (OC) when they met the father, both tended to report less severe NVP compared with previous non-users or those with less supportive partners. We provide a further test of these factors, using a large sample of women from four countries who retrospectively scored their NVP experience during their first pregnancy. METHODS: We recruited women who had at least one child to participate in a retrospective online survey. In total 2321 women completed our questionnaire including items on demographics, hormonal contraception, NVP, and partner support. We used general linear models and path analysis to analyse our data. RESULTS: Women who had used OC when they met the father of their first child tended to report lower levels of NVP, but the effect size was small and did not survive adding the participant's country to the model. There was no relationship between NVP and partner support in couples who were still together, but there was a significant effect among those couples that had since separated: women whose ex-partner had been relatively supportive reported less severe NVP. Additional analyses showed that women who were older during their first pregnancy reported less severe NVP, and there were also robust differences between countries. CONCLUSIONS: These results provide further evidence for multiple influences on women's experience of NVP symptoms, including levels of perceived partner support.

• Keywords
• Morning sickness, NVP, Oral contraceptive, Partner support, Pregnancy sickness,
• MeSH
• Contraception methods   psychology   MeSH
• Contraception Behavior psychology   MeSH
• Family Characteristics MeSH
• Child MeSH
• Internet MeSH
• Pregnancy Complications * etiology   prevention & control   psychology   MeSH
• Contraceptives, Oral * administration & dosage   therapeutic use   MeSH
• Humans MeSH
• Nausea * etiology   prevention & control   psychology   MeSH
• Retrospective Studies MeSH
• Sexual Partners * psychology   MeSH
• Social Support * psychology   MeSH
• Pregnancy MeSH
• Health Surveys MeSH
• Vomiting * etiology   prevention & control   psychology   MeSH
• Check Tag
• Child MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Comparative Study MeSH
• Names of Substances
• Contraceptives, Oral * MeSH

Optimization of chances for healthy offspring is thought to be one of the factors driving mate choice and compatibility of the major histocompatibility complex (MHC) is assumed to determine the offspring's fitness. While humans have been claimed to be able to perceive information of MHC compatibility via the olfactory channel, it remains unknown whether humans use such information for mate choice. By investigation of 3691 married couples, we observed that the high polymorphism of MHC leads to a low chance for homozygous offspring. MHC similarity between couples did not differ from chance, we hence observed no MHC effect in married couples. Hormonal contraception at the time of relationship initiation had no significant effect towards enhanced similarity. A low variety of alleles within a postcode area led to a higher likelihood of homozygous offspring. Based on this data, we conclude that there is no pattern of MHC dis-assortative mating in a genetically diverse Western society. We discuss the question of olfactory mate preference, in-group mating bias and the high polymorphism as potential explanations.

• Keywords
• HLA, assortative mating, human, mate choice,
• MeSH
• Major Histocompatibility Complex physiology   MeSH
• Humans MeSH
• Marriage * MeSH
• Reproduction genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Although anthropologists frequently report the centrality of odours in the daily lives and cultural beliefs of many small-scale communities, Western scholars have historically considered the sense of smell as minimally involved in human communication. Here, we suggest that the origin and persistence of this latter view might be a consequence of the fact that most research is conducted on participants from Western societies who, collectively, were rather old (adults), deodorized and desensitized (ODD) to various aspects of olfactory perception. The view is rapidly changing, however, and this themed issue provides a timely overview of the current state-of-the-art on human chemocommunication. Based on evolutionary models of communication, the papers cover both general mechanisms of odour production by 'senders' and odour perception by 'receivers'. Focus on specific functional contexts includes reciprocal impact of odours between infants and mothers, the role of odour in mate choice and how odours communicate emotion and disease. Finally, a position paper outlines pitfalls and opportunities for the future, against the context of the replication crisis in psychology. We believe a more nuanced view of human chemical communication is within our grasp if we can continue to develop inter-disciplinary insights and expand research activities beyond ODD people. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

• Keywords
• WEIRD, chemical communication, perception, pheromone, semiochemistry, smell,
• MeSH
• Olfactory Perception * MeSH
• Humans MeSH
• Nonverbal Communication physiology   MeSH
• Odorants * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Introductory Journal Article MeSH