Wife Had Missed Abortion Twice. Suggest Remedy

I am 29 year old and wife is 25 year old, we complete 2.5 years of marriage. We do plan for first 1.5 years and after that we try for a baby and she conceive very soon once we tried but after 2 months we come to now that baby did not have heartbeat(missed abortion) and after that we have to abort that. Same process is repeat after just after 6-7 months when we try again. Our gynecologist has done all required test of my wife and they are fine. I don’t know that where the problem is? Should I also need to go for any type of test like any type seman test, please suggest.