H. pylori is associated with fertility and pregnancy problems in some people
The diagram below is taken from a 2014 paper in the World Journal of Gastroenterology.
It shows how H. pylori infections can trigger responses in the body that lead to reduce fertility in both men and women.
My research indicates that CagA H. pylori strains represent a higher risk for fertility and pregnancy related problems.
These issues may be exacerbated in people who have existing nutritional deficiencies (especially folate, B12, iron) and in people like me who have an MTHFR gene mutation.
Note that you can test for different H. pylori strains using a DNA based stool test, which is done at home.
Details are here: