Trusting God in the mission feild

This post is for Christians. So my husband and I are seeking God's Will and beginning to prepare and train for the possibility of a Mission feild. One of the many things that's on my mind is a potential pregnancy if we were in a far off place with inadequate health care. We have always left our family planning in God's hands. But continueing to do so is a little frightening! I have had four high risk pregnancys which resulted in C section and in which a natural birth would have been impossible. We also have had many first trimester miscarriages including ones where medical supervision was needed. We have not had a child birth in 7 years but have had pregnancys resulting in miscarriage in this more recent time. (It has been a difficult few years, in this respect) We both desire more children, yet we desire God's Will whatever that is more. We also want to seek to follow God's leading to reach unreached people. Perhaps I am just giving way to fear. Any one got any thoughts or insights? Prayers appreciated!!