Talk to Gynecologist on Baby Girl Death In Womb

My wife complained of severe back pain 2 to 3 hours late after coitus & I had to rush her to the hospital where we were told the baby was dead for 3 days inside the womb. I'm still not sure why the baby died. My wife is healthy & takes good food. She did home chores like she always does. Apart from washing laundry, she carried water bucket from here & there but that's it. How can we avoid this from happening again? Kindly, give me some info. Thanks