Women who take painkillers during pregnancy could be harming the fertility of their unborn child, according to new research.

Paracetamol and ibuprofen were found to reduce the number of cells which later become eggs or sperm in babies, the study published in the journal Environmental Health Perspectives found.

Painkillers may also affect the fertility of future generations by triggering changes in the structure of DNA which can be inherited, the research found.

The findings add to a body of evidence suggesting certain medicines should be used with caution during pregnancy.

However, scientists stressed the current medical advice for pregnant women - to limit the use of paracetamol and avoid ibuprofen - remains unchanged.

Dr Rod Mitchell, the University of Edinburgh who led the research project, said: “We would encourage women to think carefully before taking painkillers in pregnancy and to follow existing guidelines - taking the lowest possible dose for the shortest time possible.