pre-eclampsia (hypertension)
Last reviewed 01/2018
High blood pressure is a useful early sign of pre-eclampsia, and is one that is closely monitored in the antenatal checkups.
The hypertension appears to be caused by the endothelial damage in PET - the endothelium has an important role to play in local vasoconstriction, and the translation of vasoconstriction into hypertension depends on the functioning of the heart.
Note that blood pressure is not necessarily raised as a result of the effect of pre-eclampsia on the cardiovascular system.
Blood pressure = cardiac output x peripheral resistance
Pre-eclampsia appears to cause an increase in peripheral resistance due to arterial spasm. However, if there is a reduction in cardiac output (associated with a reduction in circulating plasma volume - due to a transfer to the extracellular compartment and formation of oedema) then pre-eclampsia may be present without an increased blood pressure.