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 suggested "this global decline is accelerating in the 21st century," according to 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. The reasons for this are unclear. More research and measures are therefore urgently needed to prevent the fertility of men from deteriorating further.
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.