February 20, 2019

expert reaction to study on the protective effects of testosterone and ibuprofen on embryos in mice

Research published in Nature demonstrates that testosterone and ibuprofen in mice embryos may have protective effects.

Prof Ieuan Hughes, Emeritus Professor of Paediatrics, University of Cambridge, said:

“As always, one has to be careful about extrapolating the findings in rodent experiments to what may be the case in humans. The authors hypothesise lethality is more common in the female embryo (or conversely less common in the male) because of fetal exposure to testosterone which has protective anti-inflammatory effects against genetic instability in the female embryo. In one experiment, the authors induce maleness in a female embryo by transgenesis using the male determining gene, sry. Lethality is reduced in these embryos, but there are no data on the ambient testosterone levels.

“Other experiments showed that use of the anti-inflammatory drug, ibuprofen, also reduced female embryo lethality. Suggesting that these studies may have relevance to humans poses a conundrum as a number of studies have now shown anti-testis effects of ibuprofen (and to a lesser effect, acetaminophen (paracetamol)) in human grafted fetal testes to the extent that women are advised not to take ibuprofen when pregnant. So, this paper demonstrates excellent science using a rodent model but extending the results to a possible relevance for humans is a leap too far.”

Dr June Raine, Director of the Vigilance and Risk Management of Medicines Division of the Medicines and Healthcare products Regulatory Agency, said:

“Ibuprofen is not recommended for use during pregnancy, especially during the third trimester as it can increase the risk that a baby develops problems before birth and/or the risk of problems during or after delivery.  Women should speak to their doctor, midwife or pharmacist before taking medicines during pregnancy. 

“Women who take prescription medicines should speak to their doctor before becoming pregnant to see if any changes in their treatment are needed.

“The safety of all medicines is carefully monitored.  These findings will be carefully evaluated, as with any study, to determine whether they have any implications for the use of ibuprofen.”

‘Female-biased embryonic death from inflammation induced by genomic instability’ by  McNairn et al. was published in Nature at 18:00 UK time on Wednesday 20 February.

Declared interests

Dr June Raine: “None.”

No others received.