Experts do not know exactly what causes preeclampsia as of 2015, but damaged blood vessels, immune system problems and insufficient uterine blood flow are possible causes, according to Mayo Clinic. Other possibilities include genetics, high body fat and poor nutrition, according to WebMD.
Preeclampsia is a pregnancy-related high blood pressure condition. The blood vessels that develop in women with the disorder are narrower than normal, which limits blood flow to the placenta, notes Mayo Clinic. A woman in her first pregnancy has the greatest risk of developing preeclampsia. Other risk factors include pregnancy over age 40, pregnancy with more than one fetus, and pre-pregnancy conditions such as diabetes, lupus or chronic high blood pressure.