Running fever while you're expecting? Think before you pop that paracetamol in your mouth!

Why? A new study reveals that continued paracetamol intake by expectant women could have dire consequences if the baby is a boy. How? Paracetamol may reduce the production of testosterone in the unborn male child, potentially increasing the offspring's risk of testosterone cancer and infertility.

The study conducted by researchers at the University of Edinburgh, validates existing research that suggest that intake of excess paracetamol during pregnancy could heighten the risk of reproductive ailments in baby boys.

"This study adds to existing evidence that prolonged use of paracetamol in pregnancy may increase the risk of reproductive disorders in male babies," said Rod Mitchell, Intermediate Clinical Research Fellow of Wellcome Trust.

According to the researchers, pregnant women should follow current guidelines that advice against the frequent intake of the painkiller. The lowest dose should be taken for a short period if necessary.

For the purpose of the study, the researchers conducted tests on mice. The rodents were given three doses of paracetamol each day for 24 hours or seven days and had grafts of human testicular tissue.

The researchers measured the level of testosterone produced the human tissue that had been grafted into the mice after an hour of giving the final dose had lapsed. The scientists found that while there is no effect on testosterone production existed post 24 hours of treatment from paracetamol, a week-long exposure to the drug led to the reduction of the hormone by an alarming 45 percent.

Testosterone is vital for male health and reduced exposure to the hormone in the womb is said to increase risks of testicular cancer, infertility and undescended testicles.

"Most common male reproductive disorders are linked to lower testosterone exposure in fetal life, although the factors responsible for suppressing fetal testosterone remain largely unknown. Protracted use of acetaminophen during pregnancy is associated with increased risk of cryptorchidism in son," wrote the researchers.

The study has been published in the journal Science Translational Medicine.

Photo: David Pacey | Flickr