Thousands of expectant mothers were given fresh hope yesterday after scientists announced they had discovered the cause of deadly pre-eclampsia.
Experts at Cambridge University hope the results of a 20 year study will save hundreds of lives every year and pave the way for improved treatment.
Pre-eclampsia kills 50,000 mothers and half-a-million babies every year around the world and is caused by high blood pressure.
A scientific breakthrough has discovered that the condition is triggered by a protein which causes blood vessels to constrict when mixed with oxygen.
Pregnant mums are at a greater risk from the trigger because they have more oxygen in their bodies to supply their unborn babies.
Professor Peter Weissberg, Medical Director of the British Heart Foundation, believes the research offers ”real hope” for pregnant mothers.
He said: ”Every year in the UK pre-eclampsia is responsible for the deaths of around six women and several hundred babies.
”This research is of the highest quality and offers real hope for developing strategies to prevent or treat this dangerous condition by targeting the process that these scientists have identified.
”And of course, although the researchers only looked at pre-eclampsia in this study, similar strategies may be useful for those people with high blood pressure that is not effectively controlled by current medicines.”
The University of Cambridge launched a study in 1990 hoping to find the mechanism which raises blood pressure in pre-eclampsia patients.
Experts already knew that blood pressure is controlled by hormones called angiotensins which are released by the protein angiotensinogen.
Using an X-ray beam scientists discovered that the protein changes shape when it is oxidised and releases the hormone angiotensin.
Further research at the University of Nottingham proved that high levels of oxidised angiotensinogen can be found in women with pre-eclampsia.
Prof Robin Carrell, of the University of Cambridge, led the 20-year research project, and believes the breakthrough could lead to a cure or improved treatment.
He said: ”During pregnancy oxidative changes can occur in the placenta.
”These changes, the very ones we have found stimulates the release of the hormone angiotensin and lead to increased blood pressure, can arise as the circulation in the placenta readjusts the oxygen requirements of the growing foetus with the delivery of oxygen to the placenta from the mother.”
Dr Aiwu Zhou, a British Heart Foundation (BHF) Fellow at the University of Cambridge, added: ”Although we primarily focused on pre-eclampsia, the research also opens new leads for future research into the causes of hypertension in general.”
Drugs currently used to treat high blood pressure focus on the later stages of condition.
High blood pressure frequently affects pregnancy and pre-eclampsia affects between two and three per cent of mums.
The research was largely funded by the British Heart Foundation, with additional funding provided by the Medical Research Council, the Wellcome Trust and the Isaac Newton Trust.