What causes a miscarriage. had about three ultra sounds as well as vaginal before it happened and no signs but still had one..what can be the cause?

Genetic problem: Your body will automatic terminate the pregnancy if fetus has genetic problem. There's other reasons also can cause miscarriage, so you need to check with your doctor.

Hard to tell: Very sorry for your loss. Miscarriages can be caused by many things, including genetic defects with the fetus, trauma, exposure to medications/chemicals/drugs, problems with the uterus, or other events. Many women have had these occur, and gone on to have healthy children. Best of luck to you.

Genetic, Hormonal, : Miscarriages occur very frequently. The first thing i tell pts is that is isn't their fault. Most frequently there is an error as the chromosomes are dividing, during early development. Other causes include hormonal imbalances and improperly formed uterii. Most pts. Will have a successful subsequent pregnancy history, but for those that have repetitive miscarriages, it can be quite difficult.