
The history behind the questionnaire
When SPZ Lab started to offer the SDI®-testen i 2006, the common belief among researchers was that semen quality could not be changed. Few scientific publications suggested that some factors might have an effect. For example it might a good idea to quit smoking or loose weight if the body mass index was too high.
Our recommendations back then were only a few lines to encourage men who had a high DFI. But we were soon very surprised!

Improving fertility
In the autumn of 2009, SPZ Lab received a second semen sample from a German man who 3 months previously had a DFI of 41.7. The new SDI®-test showed that he had reduced DFI to 17.6. Contact with the fertility clinic revealed that the man after the first test stopped smoking. He had previously smoked 30 cigarettes per day!
The next remarkable improvement was an Irish man. During a period of 4 months, he reduced his DFI from 55.6 to 24.5! He had long been worried due to overweight and the risk of getting a diabetes type 2. The first DFI result was the motivation he needed. He immediately changed his diet and had started to exercise.

The online questionnaire
From 2009 to 2012, SPZ Lab collected a significant amount of information from men who tried to reduce their DFI. The purpose of the collection of data was to improve our knowledge so we could help other men.
The online questionnaire was used from 2011 and our collaboration with Galway Fertility and ReproMed in Ireland resulted in a presentation of our observations at the annual meeting in the European Society for Human Reproduction and Embryology (ESHRE) in 2017.
The online questionnaire is now recommended routinely for all men who wants to improve their DFI.