Pregnant women have been warned that there could be a link between eating tuna (and swordfish) and autism in the unborn child (the baby in the pregnant mother could be at higher than normal risk of autism).

The researchers from the USA say that levels of mercury in tuna and swordfish (oily fish from the sea, not rivers) could be contributing to the rise in childhood autism today.

The number of children with autism has risen alarmingly over the last twenty years.

Some believe the reason is environmental, others think it is because we are getting better at diagnosing various levels/grades of autism.

In the UK, the Food Standards Agency is telling pregnant and breastfeeding women to limit their consumption of tuna to two can a week (medium sized ones).

Other experts, on the other hand, say there is a great deal of evidence to show a very positive link between seafood and pregnancy.