Hypertension and pregnancy
Izelle Theunissen, MRC News
One of the most dangerous conditions a pregnant woman can suffer from, is
hypertension. The Pregnancy Hypertension Research Unit investigates ways to
solve the problem.
Hypertensive disorders are the most frequent reasons for pregnant women dying
- not only in South Africa, but world-wide. Although there might be many factors
contributing to a woman developing dangerously high blood pressure (some attend
antenatal care only at a very late stage), the exact cause of the disorder isn't
known at this stage.
Prof. Jack Moodley, who heads up the Research Unit, says his team's work is
aimed at managing and treating the patients appropriately. He cites their work
on eclampsia as an example. This is a very dangerous complication of
hypertension, and is characterised by fitting or convulsions and protein in the
urine.
"We were one of the very few centres in the world who participated in a
trial comparing the use of magnesium sulphate with other anticonvulsive drugs.
We've shown quite clearly that magnesium sulphate is the best drug to prevent
further convulsions," he says.
The results from that study, dubbed the Eclampsia Collaborative Study, has
caused magnesium sulphate to become the anticonvulsant of choice. It is now used
at almost 99% of all sites in South Africa. "The Unit did a survey of all
gynaecologists in the country, and most of them used magnesium sulphate,"
Prof. Moodley adds.
The Unit is currently involved in another study on magnesium sulphate,
determining whether is could be of use for preventing convulsions in the first
place (not to be confused with administering magnesium sulphate only after
fitting has occurred). "This is a world-wide study involving approximately
10 000 patients. It is run from Oxford and we are the South African co-ordinating
site. The study has implications for us in South Africa, because if it shows
that magnesium sulphate is useful, we'll have to give it to everybody - which
will add to the workload of health care workers," he explains.
The drug should also be administered very carefully. If it is given too
rapidly, it can cause cardiac and respiratory arrest. "Therefore many
people say you should keep patients under continuous nursing care. That is one
of the major disadvantages. But if it could prevent women from fitting, you
would definitely decrease morbidity and mortality," says Prof. Moodley.
The Unit is also studying various aspects of the physiopathology of the
disease. "We've been looking at various substances which could play a role
in the placental bed, such as insulin growth factor and nitric oxide, because
these are substances that cause vasodilation," he says.
Prof. Moodley's own particular interest is the clinical aspects of the
condition. "I'm studying whether it's necessary to give antihypertensive
drugs to women with mild hypertension. The standard treatment is to put the
patient on a drug right away. But maybe all that is required is bed rest,
relaxation and staying off work for a few weeks. This might be just as effective
as the drugs."
For more information about hypertension in pregnancy, please contact Prof.
Moodley at tel.: (031) 260-4250 or e-mail: jmog@nu.ac.za.
Article courtesy of the MRC News (Medical
Research Council, South Africa)
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