What is preeclampsia and how do i know if i have it?

See below: It is an illness characterized usually in the latter stages of pregnancy by fluid retention in the legs and face and alarmingly increasing BP measurements. Untreated it can lead to stroke and even death and fetal demise.

Headache, High BP: Sometimes abnormal placentas begin to breakdown at 20wks, leading to exposure of mom to some of dad's placental genes and lead to an "allergic" reaction where the vessels spasm and platelets are drawn away (thrombocytopenia). The spasm causes high BP, HA, liver dysfunction, vision changes, and protein in the urine; leads to maternal seizure, decreased baby growth, and sometimes placental abruption