Eating too much oily fish during pregnancy may increase the risk of delivering the baby too early, scientists believe.
The researchers told New Scientist magazine the harm is probably caused by high mercury levels in oily fish such as mackerel, salmon and sardines.
But experts warn it is important for pregnant women, and indeed everyone, to eat enough fish to keep healthy.
Pregnant women should eat fish twice a week, says the Food Standards Agency.
Source - BBC