Warning over pregnancy steroids

Women at risk of going into early labour are given steroids

Pregnant women at risk of delivering early should not be given too many doses of steroids, say researchers.

The drugs are given to promote lung development in the foetus and increase the chances of survival.

But a study of 1,800 women suggested multiple courses of steroids do not improve outcomes after premature birth and may lead to smaller babies.

Doctors should stick to one course of treatment, the Canadian researchers wrote in The Lancet.

The first trial of steroid treatment in mothers of babies at risk of being born prematurely was carried out in the 1970s.

There is a big difference between giving steroids every week and giving them once or twice Professor Andrew Shennan, St Thomas's Hospital, London

By the 1990s it had been established that a single course of treatment was beneficial for the baby.

But Dr Kellie Murphy, study leader and obstetrician at Mount Sinai Hospital in Toronto, said doctors then began to give further doses if women did not have their baby soon after the first course of treatment.

Some women, including patients in the UK, received treatment every seven to 14 days, she said.

Birth weight

In the study, women who were 25 to 32 weeks into their pregnancy and had received one course of steroids, but had not given birth after seven to 14 days, were either given further courses of steroids or a placebo.

Babies exposed to multiple steroid doses had very similar outcomes to those who had had only one dose.

But they weighed around 100g less at birth, were shorter and had a reduced head circumference.

The researchers are planning to follow the babies to the age of five to monitor if they develop any neuro-developmental problems.

"Our trial showed quite clearly there is the possibility of risk with repeated doses," Dr Murphy said.

"Even with one extra dose we need to be very cautious."

Professor Andrew Shennan, an obstetrician at St Thomas's Hospital in London, said the study was addressing a very practical issue.

"There is an opportunity to give many courses quite often," he said.

"But there is a big difference between giving steroids every week and giving them once or twice.

"If you give a dose to a woman at 24 weeks, by 28 weeks I would be happy to give another."

Dr Ronald Lamont, spokesman for the Royal College of Obstetricians and Gynaecology, said it used to be common practice to give steroids every 10 days or so.

"This confirms what we've suspected for a while."

He said doctors needed to "optimise" when they delivered the one dose.

"If you have a woman in spurious labour at 23 weeks, don't rush in - wait until you're sure it's the real thing."