SPERM count is not the only factor to be considered when diagnosing male infertility, according to a study to be published on Thursday in the New England Journal of Medicine. Researchers say several other factors can lead to infertility, such as the size and structure of sperm cells, in a study that calls into question World Health Organization (WHO) standards for defining infertility. Current laboratory methods used to determine infertility do not take these additional factors into account, say the experts, who analysed the sperm of 1 500 men in the United States. ”Up until now, we’ve just been using guidelines without rigorously testing them,” said David Guzick, who conducted the study along with a team of experts from the University of Rochester in New York state. The study is the first to use modern technology to compare the sperm of fertile and infertile men, as previous studies had only compared the sperm of those men under fertility treatment, the experts write. According to the WHO, the ”normal” sperm count is 20-million cells per millilitre, at least 50% of which are in motion, with any lower count considered to be ”abnormal”. – Sapa-AFP