Study hyperlinks geography to important variations in sperm high quality

A brand new nationwide research has discovered substantial regional variations in sperm high quality, with males within the highest-performing area recording virtually double the full motile sperm rely of these within the lowest-performing area.

Presented at present on the forty second Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE), the research discovered that way of life habits have been broadly related throughout areas and didn’t clarify the variations noticed, elevating vital questions in regards to the function of environmental exposures in male reproductive well being.

The potential multicentre research analysed semen high quality and way of life knowledge from 386 males present process fertility evaluation throughout seven assisted replica centres in Spain between June 2024 and December 2025.

Participants accomplished a standardised questionnaire masking elements together with residence, physique mass index (BMI), medical historical past, bodily exercise, chemical publicity, medicine use, smoking, alcohol, drug and occasional consumption.

Researchers then in contrast semen parameters throughout 4 areas of Spain – north, south, southeast and central – to find out whether or not geographical variations in sperm high quality may very well be defined by way of life or socio-demographic elements.

The outcomes revealed important regional variations in semen quantity, sperm focus, motility, morphology and complete motile sperm rely, in addition to the prevalence of asthenozoospermia (diminished sperm motility) and teratozoospermia (irregular sperm morphology).

Men residing in northern Spain recorded the strongest semen high quality total, with a mean complete motile sperm rely of 94.35 million, in contrast with 50.11 million in central Spain. 

The northern area additionally had the best common sperm focus (80.96 million/ml) and sperm motility (44.79%). Reduced sperm motility affected 23.9% of males within the north, in contrast with 55.4% in southern Spain and 53.4% in central Spain.

Despite these variations in semen high quality, way of life habits and total way of life patterns have been broadly related throughout the 4 areas studied. After adjustment for all measured way of life and socio-demographic elements, solely geographical location and abstinence length remained independently related to semen parameters.

Total motile sperm rely was independently related to each geographical location and abstinence length, whereas geographical location alone remained considerably related to the prevalence of diminished sperm motility and irregular sperm morphology.

What was most outstanding for us was that the strongest semen high quality parameters have been constantly present in northern Spain. At the identical time, we have been shocked to seek out that way of life habits have been very related throughout all of the geographical areas studied.”

Professor Rocío Núñez-Calonge, Lead Author

“If, based on the results of this study, we rule out male lifestyle habits as the explanation for the geographical differences observed in semen quality, it seems likely that these variations may instead be related to differences in environmental exposure, such as levels of pollution or other environmental contaminants present in those areas,” Professor Núñez-Calonge defined.

Professor Núñez-Calonge famous that the findings might have implications past Spain, with research from a number of international locations reporting important regional variations in semen high quality, significantly in areas with marked environmental heterogeneity.

Looking forward, Professor Núñez-Calonge stated: “Given the widespread presence of air pollution in many urban environments, its potential effects on male fertility deserve further investigation.”

“Larger and well-designed studies are needed to better clarify the relationship between environmental exposure and semen quality. At the same time, stronger public health policies aimed at reducing exposure to pollutants, industrial chemicals and plastic-derived compounds should be considered as a priority for protecting reproductive health in future generations,” Professor Núñez-Calonge concluded.

Commenting on the broader implications of the research, Professor Dr Karen Sermon, Immediate Past Chair of ESHRE, stated: “While it is well established that a healthy lifestyle has a positive effect on sperm quality, the effect of environmental factors that are beyond the control of the individual are clear and need to be tackled at societal and political level. There is a clear responsibility for national and EU regulators in this matter.”

The research summary can be revealed at present in Human Reproduction, one of many world’s main reproductive medication journals.