Bacteria found living in the foods heightens their risk of suffering a miscarriage, scientists claim.
Soft cheeses can contain listeria bacteria that cause an infection called listeriotic. To avoid this risk, pregnant women are advised not to eat any mould-ripened soft cheese such as brie, camembert, mould-ripened soft cheese made with goats' milk, and others with a similar rind.
Experts say listeria - a common food poisoning bug - can attack the placenta and the lining of the uterus, causing new life to be rejected by the body.
The new research by University of Wisconsin-Madison School of Veterinary Medicine found it's a severe risk factor in early pregnancy too.
Symptoms caused by listeria can be similar to flu and include a high temperature, muscle ache or pain, chills, feeling or being sick and diarrhea.
But when it occurs, it may go unnoticed because the few recognizable symptoms are nearly indistinguishable from the discomfort most newly pregnant women feel.
Researchers provided a strain of listeria that caused miscarriage, stillbirth and premature delivery in at least 11 pregnant women in 2000.
Whatever you buy, always make sure the label says "pasteurized" on it, and talk to your doctor if you aren't sure about a certain cheese.