More Babies are Born In the Autumn: Is Sperm Quality to Blame?
Ever wondered about seasonal birth patterns? In the US, more babies are born between July and September (which means conception took place between October and December) and relatively few babies are born in the spring (conceived in the summer months).
Do we tend to cuddle up more during colder months? Sure. But it might also have something to do with seasonal variation in sperm concentration/quality!
A well-designed scientific study showed just that.
We know that sperm needs to stay a few degrees cooler than body temp. And if the scrotal temperature gets too hot, sperm concentration, motility, and morphology all start to take a big hit.
So it’s really no surprise that this study found seasonal variations in sperm quantity and quality. It may even partly explain the seasonal highs and lows of babies being born!
Levitas et al. 2013. Seasonal variations of human sperm cells among 6455 semen samples: a plausible explanation of a seasonal birth pattern. Research Reproductive Endocrinology and Infertility 208(5), 406. doi:10.1016/j.ajog.2013.02.010.