There are some basic Pre Marital Medical tests and it vary from country to country.
They are as follows:
1) First assess general health status
2) Detect infectious disease like HIV, Hepatitis B
3) Screen hereditary condition that effect offspring like Thalassemia
, Hemophilia, Sickle cell anemia
4) Screen for fertility status like semen analysis
,assess of reproductive organ.
I think you get some valuable information.