Sporting tournaments and changed birth rates 9 months later: a systematic review.

Introduction: Major sporting tournaments may be associated with increased birth rates 9 months afterwards, possibly due to celebratory sex. The influence of major sporting tournaments on birth patterns remains to be fully explored. Methods: Studies that examined the relationship between such events and altered birth metrics (number of births and/or birth sex ratio (male/total live births)) 9(±1) months later were sought in PubMed and Scopus and reported via standard guidelines. Database searches were conducted up to 7 November 2022. Results: Five events led to increased birth metrics 9(±1) months later and these included the Super Bowl, the 2009 UEFA Champions League, the 2010 FIFA World Cup, the 2016 UEFA Euros and the 2019 Rugby World Cup. Several la Liga soccer matches also had effects. With a few exceptions, major American football, Association football (soccer) and Rugby apex tournaments in Africa, North America, Asia and Europe were associated with increases in the number of babies born and/or in the birth sex ratio 9(±1) months following notable team wins and/or hosting the tournament. Furthermore, unexpected losses by teams from a premier soccer league were associated with a decline in births 9 months on. Conclusions: This systematic review establishes that major sporting tournaments have a notable impact on birth patterns, influencing both birth rates and sex ratios. Emotional intensification during these events likely triggers hormonal shifts, driving changes in sexual activity and subsequently shaping birth rates, often positively, about 9 months later. The context is crucial, especially when a region/country hosts a major single-sport tournament or participates for the first time, as population excitement is likely to be at its peak. These findings hold significance for healthcare planning and highlight the role of societal events in shaping demographic trends. PROSPERO registration: CRD42022382971.

STROBE, CONSORT, PRISMA, MOOSE, STARD, SPIRIT, and other guidelines - Overview and application.

The purpose of research is to seek answers and new knowledge. When conducted properly and systematically, research adds to humanity's corpus of knowledge and hence to our general advancement. However, this is only possible if reported research is accurate and transparent. Guidelines for all the major types of studies (STROBE, CONSORT, PRISMA, MOOSE, STARD, and SPIRIT) have been developed and refined over the years, and their inception, development, and application are briefly discussed in this paper. Indeed, there are currently over 250 of these guidelines for various types of medical research, and these are published by the EQUATOR network. This paper will also briefly review progress in acceptance and adoption of these guidelines.

Tendências seculares das proporções de nascimentos entre gêneros na América do Sul durante a segunda metade do século XX / Secular trends in sex ratios at birth in South America over the second half of the 20th century

OBJETIVOS: Analisar as tendências seculares e gradientes de latitude na proporção masculino-feminina ao nascimento (M/F: masculinos divididos por total de nascidos vivos) no Continente Sul Americano. MÉTODOS: Os dados sobre nascidos vivos masculinos e femininos em âmbito nacional, durante um ano por país, foram obtidos da Organização Mundial da Saúde e analisados com tabelas de contingência. O continente foi arbitrariamente dividido em duas regiões: a primeira: de 10º acima da linha do Equador até 20º abaixo da linha Equador (10º N-20º S), e uma segunda abaixo de 20º da linha do Equador (> 20ºS). RESULTADOS: O estudo analisou 147.773.689 nascidos vivos. Encontrou-se uma tendência crescente M/F na maioria dos países próximos ao Equador (10º N-20º S) (p = 0,004). A análise do período entre 1950 e 1974 não mostrou diferença, porém após este período (1974-1996) encontrou-se um aumento M/F (p = 0,03). Um aumento na proporção M/F foi encontrado em todo o período na região > 20ºS (p < 0,0001). Também foi observado um gradiente de latitude, nascendo mais lactentes masculinos em latitudes mais frias (mais ao sul, > 20ºS) (p < 0,0001). CONCLUSÃO: A proporção M/F está crescendo na América do Sul, diferentemente do presente declínio na Europa e na América do Norte. Este estudo também mostra que os gradientes de latitude para a proporção M/F são semelhantes àqueles anteriormente publicados na América do Norte, nascendo mais bebês masculinos nas latitudes mais frias, ao contrário das tendências publicadas na Europa. É provável o inter-relacionamento de vários fatores ainda pouco entendidos.

OBJECTIVES: Latitude gradients have been found in the male-female ratio at birth (M/F: male divided by total births), which is anticipated to be 0.515. METHODS: Annual national male and female live births by country were obtained from the World Health Organization (WHO) and analysed with contingency tables. The continent was arbitrarily divided into two regions: a region 10º above the Equator to 20º below the Equator, and a second area 20º below the Equator. RESULTS: This study analyzed 147,773,689 live births. An overall increasing trend in M/F was found for the region >20º (p < 0.0001) for the entire period. For the aggregate, a significant decrease was present for the period 1950-74 (p = 0.01) followed by a significant increase thereafter (p < 0.001). A latitude gradient was also noted, with more males being born in cooler (more Southern > 20º S) latitudes (p < 0.0001). There were 3,765,648 male births in excess of what was anticipated. CONCLUSION: The M/F ratio is increasing in South America, unlike the decline present in Europe and North America. This study also showed that M/F latitude gradients are similar to those previously reported in North America, with more males being born in cooler latitudes, contrary to the trends reported in Europe. The interplay of several poorly understood factors is likely.