According to new research, the more male siblings your partner has, the greater likelihood you’ll produce a large number of progeny together–or he’ll at least be fertile enough to do so…if Von Trapp family proportions are your thing.
Scientists have found that the number of brothers a man has is linked to his fertility.
A research team from the University of Sheffield analysed the sperm motility (travel speed) of 500 men, measuring the results against their family make-up.
“We found the greater number of brothers, rather than sisters, a man has the faster his sperm is, increasing the likelihood of fertility,” says study researcher Dr Allan Pacey.
“Lots of brothers is also an indication that the man’s parents have strong male fertility genes, and they would then be passed on to the son,” explains Dr Pacey.
“The results are very surprising and could provide genetic insights into why some men are more fertile than others.”
Of course, researchers emphasised that men with more women in the family are not at risk for the converse; a large number of sisters is not necessarily indicative of low fertility. Further, the correlation between women and their siblings with regards to fertility was also not examined by the study team.
Either way, the study is one of many that highlights the paternal importance in reproductive health–it’s not just down to Mum.