A new study confirms fears that sperm counts are declining in men around the world. And finally even at an ever increasing pace. So far there are only assumptions about the causes. It is also unclear whether fertility also suffers.
The number of sperm in men is decreasing at an accelerating rate worldwide, according to a new study. Between 1973 and 2018, the average sperm concentration fell by more than 51 percent - from 101.2 million to 49 million sperm per milliliter of semen. The data also indicated "that this global decline is accelerating in the 21st century," says the study, published Tuesday in the journal Human Reproduction Update.
According to the researchers led by the Israeli epidemiologist Hagai Levine, the number of sperm is currently falling at a rate of 1.1 percent per year. For their meta-analysis, the researchers evaluated the data of more than 57,000 men from 223 studies in 53 countries. It essentially confirmed the findings of a 2017 study, which was criticized for only including data from North America, Europe, Australia and New Zealand.
But does that actually mean that male fertility is also declining? This is controversial among experts. The World Health Organization (WHO), for example, defines a normal level of sperm at between 15 and 259 million per milliliter. The status determined by the current study would therefore still be within this range.
Also, the number of sperm does not necessarily say anything about the fertility of an individual man: Men with few sperm can be fertile, but neither can those with many.
However, there are also indications of an increasingly infertile society: in Germany, for example, the number of artificial inseminations has increased in recent years. However, this could also have other reasons. Like the fact that couples are having children later on average and the likelihood of getting pregnant naturally decreases with age.
(This article was first published on Wednesday, November 16, 2022.)