Thank you for writing to us.
The answer to your question is YES, an uncontrolled glucose
level can not only affect male fertility but can also affect female fertility as well. In fact in about 35% of infertility
cases among couples, the male is diagnosed as being infertile with about 20% of cases affecting both partners.
Therefore, it is of utmost importance that your fiance's blood glucose levels should be brought under control as not only can it affect fertility but in the long run it can affect his erection and may make him impotent.
So the bottom line is that he should keep his diabetes
well in control because this can not only cause problems with fertility but can also affect other organs of his body and his well being.