For decades, pregnant women have been told that acetaminophen, widely known by the brand name Tylenol, was the only safe pain reliever they could take. Until now.
New studies have shown that the drug – also known as paracetamol and used to reduce fever and treat common headaches or muscle pain – could affect the fertility of female babies because it causes them to have fewer eggs than those not exposed to the medicine. It's also been shown to have adverse effects on baby boys by raising the risk of infertility and some cancers.
The study, conducted at the University of Edinburgh's MRC Centre for Reproductive Health, was performed on rats and concluded that taking acetaminophen for just one day had no effect but treatment three times a day for a week caused hormone levels to nearly halve.
Despite the fact that fetal development is slower in humans than in rats, study co-author Richard Sharpe believes there are substantial similarities between the two reproductive systems.
For those women pregnant and uncertain of what they should do, Adam Balen, chairman of the British Fertility Society, said it best: "This is an interesting study of long-term use of paracetamol in pregnant rats and so, whilst we must be cautious extrapolating to humans, it is sensible for pregnant women to minimise use of paracetamol and other painkillers and seek medical advice if they experience problems with significant pain in pregnancy."