by University of Tsukuba

Credit: Unsplash/CC0 Public Domain

With declining birthrate becoming a social problem, the number of couples in Japan suffering from subfertility due to male factors is reported to be one in 10.

A well-documented cause of subfertility is "spermatogenesis dysfunction," which refers to challenges with the process of sperm production, such as low sperm count or poor motility. These causes can be identified via semen analysis at a fertility clinic.

However, semen analysis results can show noticeable day-to-day changes, even for the same person, with results differing greatly each time an analysis is conducted.

In several situations, relying solely on sperm concentration and motility in semen analysis does not allow medical professionals to identify the cause of subfertility in male patients. Thus, several men are currently suffering from subfertility without knowledge of a clear cause.

Researchers at University of Tsukuba have developed a new method for evaluating subfertility by focusing on trace elements in the seminal plasma (the liquid part of semen) and blood serum. The paper is published in the journal Reproductive Medicine and Biology.

The researchers calculated the concentration ratios of 20 trace elements in seminal plasma relative to serum concentrations and used these values to classify 245 male patients with subfertility using an unsupervised machine learning method.

The researchers confirmed that the proportion of the woman partners of the male patients in whom spontaneous pregnancy occurred within one year of starting infertility treatment was higher in the group with low concentrations of phosphorus and arsenic and high concentrations of other trace elements than in other groups, indicating that the method for evaluating subfertility developed in this study may be effective.

This study's results could contribute to the development of new fertility treatment methods based on trace element analysis and the improvement of pregnancy rates.

More information: Takazo Tanaka et al, A new clustering model based on the seminal plasma/serum ratios of multiple trace element concentrations in male patients with subfertility, Reproductive Medicine and Biology (2024). DOI: 10.1002/rmb2.12584

Provided by University of Tsukuba