News

24th May 2004

Common painkillers a headache for baby boys

The research reported in the journal Nature Neuroscience by Prof Margaret McCarthy of the University of Maryland, Baltimore, reinforces the advice given to women that unnecessary drugs should be avoided where possible in pregnancy.

Professor Mc Carthy has studied how the male sex hormone testosterone sends out orders in the womb to make the brain more masculine, using locally acting hormones called prostaglandins.

They discovered that one prostaglandin, PGE2, played an unexpected role in brain development in rats. Drugs such as aspirin and indomethacin can block its manufacture in the body and interfere with brain masculinisation and later male sexual behaviour in rats, reducing their sex drive.

If this is also true in humans the finding raises concerns about indomethacin, used to treat premature labour, although aspirin is already generally avoided during pregnancy.

Prof Ieuan Hughes, of the University of Cambridge, commented, “This a beautifully conducted study with convincing results. However, it would be a quantum leap to extrapolate this data to humans as we know so little about sexual hardwiring of the brain around birth.

“Women are occasionally given low-dose aspirin to prevent miscarriage and on the basis of this study this should not change. But, as with any medication, it is worth avoiding while pregnant where possible.”

Commenting on the implications, three scientists writing in the journal suggest, “Even now there may be some husband out there saying, in effect, 'Sorry, dear, not tonight. My mother had a headache 30 years ago.”

Prof Nigel Brown, the professor of developmental biology at the University of London, says rats are used to study the brain and sexual behaviour because they have an easily identifiable area of brain that differs in males and females.

He goes on to say “It makes good sense to look further at non-steroidal anti-inflamatory drugs in this context. In the meantime, we should continue to follow current advice and be cautious.”

• Could there be some truth in this or is it just more scaremongering? Tell us what you think in Discuss, Debate and Deliberate
• Find out more about medicines and pregnancy