What causes miscarriages? I know there are many causes, but what would you say the most common are and what can be done to prevent them?
It is hard to say what the most common cause is since in most cases the cause is never actually determined. If it happens repeatedly though then then I would suspect that the problem is likely either a weak cervix, consumption of uterine stimulants, hormone problems or possibly the mother's immune system is attacking the fetus.
Also, I had a friend that was pregnant and her water broke after only 18 weeks. What causes this
Again there are a number of causes. Infection of the female organs or in the infant is the most common cause. Other causes include injury, excess amniotic fluid, abnormally large babies, incorrectly positioned fetus, cervical issues, etc.
and what can be done to prevent this? She was on bed rest and delivered at 29 or so weeks.
There is very little that can be done to prevent premature rupture of the amniotic membrane.
The risk of premature labor on the other hand can be minimized with red raspberry leaf tea throughout the pregnancy to tone and relax the uterus. Supplementing with magnesium malate or citrate can also help by relaxing the uterus and can also help with preventing preeclampsia.