Suggest Methods To Prevent Miscarriage

My niece is 42yrs of age with a gestational age of 35 weeks, she had an ultrasound and was told they do not see a stomach in the fetus. she has not been feeling well, she's retaining fluid, no bleeding. she has had miscarriages in the past. she is considered high risk. she resides in Dominican Republic... I am afraid they might not be giving her the correct diagnosis and if so what can be done at this point.