Clean cooking stoves may reduce hypertension in pregnant women

Replacing biomass and kerosene cook-stoves used throughout the developing world with clean-burning ethanol stoves may reduce hypertension and cardiovascular risk in pregnant women, according to new research published online, ahead of print in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

In “Randomised Controlled Ethanol Cook-stove Intervention and Blood Pressure in Pregnant Nigerian Women,” researchers report that the frequency of developing hypertension and diastolic blood pressure (the bottom number) were decreased in pregnant women who cooked with ethanol, rather than with traditional cook-stoves fueled by wood or kerosene. Systolic blood pressure (the top number) did not change significantly.

“Although previous studies found that exposure to household air pollution increased the risk of adverse pregnancy outcomes, no randomised, controlled trial had investigated whether clean-burning fuel would reduce the incidence of hypertension in pregnant women,” said lead study author, Christopher O. Olopade, MD, MPH, professor of medicine and family director of international programmes at the University of Chicago’s Pritzker School of Medicine.

Dr Olopade and his colleagues enrolled 324 pregnant women living in Ibadan, Nigeria, in their study. Women who smoked or lived with a smoker or who cooked for a living were excluded from the study. None of the women enrolled were hypertensive when they enrolled and were randomised into the study between the 16 and 18th weeks of pregnancy.

Half of the participating women who previously cooked with firewood or kerosene were randomly assigned to cook with ethanol. The other half continued to cook with either wood or kerosene. Blood pressure was recorded during six patient visits.

Dr Olopade said the findings support the call by the World Health Organisation to remove kerosene as a home cooking or heating fuel.

All participants were informed about the harmful effects of smoke exposure, and women cooking with either fuel were encouraged to cook outside or in a well-ventilated room.

“The results of our study add to the evidence that vulnerable populations, especially pregnant women, would gain important health benefits from stoves that burn clean fuels,” Dr Olopade said.

“Additional studies are still needed to determine how much of a reduction in exposure levels will result in significant and sustained health benefits.”