Experts don't know the exact cause of preeclampsia.
But it may start with a poorly developed placenta that doesn't circulate blood normally. What causes this placenta problem isn't yet clear. Experts also don't know why the mother's body then develops high blood pressure.
Immune system response
Preeclampsia occurs most often in women who are pregnant for the first time and in women who have been pregnant before but now have a first pregnancy with a different man.
Exposure to an Reference antigen Opens New Window from the father (in the growing placenta or fetus, for example) may trigger an immune response in the woman's body. This immune response—the body's way of fighting infection—may result in narrowing of the blood vessels throughout the body, causing higher blood pressure and other problems.
|By:||Reference Healthwise Staff||Last Revised: Reference November 5, 2012|
|Medical Review:||Reference Sarah Marshall, MD - Family Medicine
Reference William Gilbert, MD - Maternal and Fetal Medicine