'Happy' pills put newborns at risk

Prozac-type antidepressants can raise the risk of a potentially deadly breathing problem in newborns but only if the mother takes them during the second half of pregnancy, a study shows. A team led by Christina Chambers of the University of California at San Diego found that women taking selective serotonin-reuptake inhibitors, the drug class that includes Prozac, were six times more likely to have a baby suffering from persistent pulmonary hypertension of the newborn (PPHN).

In moderately severe cases, PPHN kills about up to 20 per cent of babies and half the survivors are left with serious abnormalities.

However, Dr Chambers and her colleagues found that exposure to the medicines posed no risk during the first 20 weeks of pregnancy. Nor did other classes of antidepressants.

Sandra Kweder, deputy director of the Office of New Drugs at the US Food and Drug Administration, called the result "very worrisome," especially when pregnant women can be prone to depression.

Women who were already taking such drugs "should not stop the medicine on their own", she said.

That was because sudden withdrawal could be even more dangerous than the relatively low risk of PPHN.

Instead, they should talk to their doctors to assess the risks and benefits.

"It isn't a cause for panic," Dr Kweder said.

PPHN is already seen in about 1 out of 500 babies, "so even an increase in risk by a factor of five or six would not result in a large number of cases," said James Mills of the National Institute of Child Health and Human Development in Bethesda, Maryland.

In an editorial in this week's New England Journal of Medicine, where the study appears, Dr Mills estimated that if Chambers results are correct, taking Prozac-type drugs would cause about 40 extra cases of PPHN a year in the United States.

"To put it in other terms, about 99 per cent of women exposed to one of these medications late in pregnancy will deliver an infant unaffected by PPHN," Dr Chambers and her colleagues concluded.

Because the safety of many drugs has not be evaluated in pregnant women, Dr Kweder said the work by Dr Chambers and her colleagues "is the kind of study that's needed to assess the safety of drugs during pregnancy."

- REUTERS