Is there anything you can do to prevent pelvic support problems?

Kegel exercises. Frequent kegel exercises, fast, slow and holding, 50 times a day will help. Keep your weight down and your core strong so your center of gravity doesnt shift. Avoid heavy lifting that isnt necessary and dont gain too much weight during any pregnancy.
Kegel exercises. Kegel exercises have been shown to be helpful in reducing pelvic floor dysfunction. Biofeedback has also played some role in helping as well. Medications are not very effective in its treatment.
Yes. Avoid heavy lifting, & smoking. Pregnancy with vaginal delivery has been shown to increase risk. Treat any chronic pulmonary conditions such as cough. Treat constipation do pelvic floor exercise. Consider vaginal estrogen if menopausal. Basically avoid anything that increases intraabdominal pressure. Straining, cough, heavy lifting, etc.