The cause of ‘unexplained infertility’ for 80% of couples trying to have a baby has been discovered by researchers from Queen’s University Belfast and published in the journal Reproductive BioMedicine Online.

According to the report, around 50,000 couples in the UK, and 1 million couples worldwide, undergo fertility treatments every year. Upwards of one third of them are told that they have unexplained or idiopathic infertility, meaning doctors cannot seem to find anything wrong with either the male or female after analysis of sperm and fallopian tubes or uterus.

Professor Sheena Lewis from the School of Medicine, Dentistry and Biomedical Sciences at Queen’s has found that around 80% of couples who are diagnosed with unexplained or idiopathic infertility have a known cause called high sperm DNA damage. The new trial can help these couples understand better treatment options, which will keep them from wasting their money, time, and emotions.

Lewis explained:

“The majority of couples experiencing problems with fertility are able to receive an explanation for their infertility. These causes range from low sperm count, poor sperm motility in the man to blocked falllopian tubes or endometriosis in the women. Once the causes for infertility have been established the appropriate course of assisted conception treatment can be undertaken.

For almost one third of couples, until now, there has been no obvious cause for infertility and these couples are given the diagnosis of ‘unexplained fertility’. These couples often invest a lot of time and money in fertility treatments like intrauterine insemination (IUI) unlikely to be successful. In our study we have now had a breakthrough which explains the cause of infertility for many of those couples. Now that we have found the cause of infertility for many of those couples suitable treatments can be tailored for them which will direct them straight to the best treatment and increase their chances of having a baby.”

The other significant finding revealed by the study is that it is the first to present evidence suggesting that the likelihood of conceiving after IVF is linked to the amount of damaged DNA a man’s sperm contains. A small amount of damage (less than 15% of sperm) is considered normal. However, if the damage reaches more than 25% of sperm, the chances of having a baby are lowered, even if the couple is going through fertility treatment.

The new evidence, which came from over 500 couples, and utilized the male fertility test called SpermComet, is the most recent from a round of trials conducted by the well-known male fertility experts at Queen’s Centre for Public Health.

Lewis concluded, “We are Queen’s have developed the SpermComet, which is a unique test for male infertility that measures damaged DNA in individual sperm – providing all couples with specific information about the causes and extent of their infertility. This test can predict the success of infertility treatments and fast-track couples to the treatment most likely to succeed, leading to reduced waiting times and improved chances of success. With one million couples worldwide requiring fertility treatment, these new research findings will give many fresh hope of having a family.”

Written by Christine Kearney