Study results suggest that a simple hormone-blocking drug may help prevent a rare form of heart failure, called peripartum cardiomyopathy, in pregnant women or those who have recently given birth.

Peripartum cardiomyopathy affects around one in every 1300 to 4000 women who give birth, and stops the heart being able to pump blood effectively around the body.

Until now, doctors were unsure why some women developed the condition during pregnancy and after childbirth, and prescribed traditional heart failure drugs, such as beta blockers and ACE inhibitors, to treat the condition.

However, in animal tests, Dr Denise Hilfiker-Kleiner, from Medizinische Hochschule in Hannover, Germany, and team found that an altered form of the hormone prolactin may be involved in the development of peripartum cardiomyopathy.

The production of prolactin is increased during pregnancy to stimulate breast growth and milk production.

Moreover, the researchers report that a drug called bromocriptine, which blocks the release of prolactin in the body, may protect against the development of peripartum cardiomyopathy.

In an initial study, they gave bromocriptine to six pregnant women who had developed this form of heart failure in a previous pregnancy and found that the treatment was effective.

"In all the women who have received the bromocriptine treatment, it has worked," said Dr Hilfiker-Kleiner. "It has prevented them from getting the disease again."

She added that if the initial findings are confirmed by further research, “this drug could really make an immediate difference" for women at risk of peripartum cardiomyopathy. The study is published in the journal Cell.