What are the causes of pregnancy-induced hypertension?

PIH: There are four types of high blood pressure (hypertension) that can occur in pregnancy: preeclampsia, chronic hypertension, preeclampsia superimposed on chronic hypertension and gestational hypertension. Please see this link for complete info: http://bit.Ly/extems.

Chronic/preeclampsia: Hypertension occurs in 3-4% pregnancies. Most times it is a reflection of essential HTN (perhaps exacerbated by wt gain and increased plasma volume). Htn occurring after 20 weeks might reflect preeclampsia and if associated neurological changes, eclampsia . Thyroid abnormalities later in pregnancy can also affect BP and cause htn.