Food safety is extremely important during pregnancy. This is because bacterial toxins and certain harmful chemicals such as alcohol and methylmercury can pass from mother to baby, and cause undesirable outcomes.

Avoid:
Unpasteurised milk;

Soft cheeses, e.g. brie, feta, camembert and roquefort;

Liver pates;

Uncooked hot dogs, ham and luncheon meats

These foods are prone to Listeria monocytogenes, a bacteria that causes listeriosis, which may result in miscarriages and stillbirth.

Avoid:
Raw or undercooked meat,

Poultry,

Seafood, e.g. raw oyster, cockles, sashimi and sushi;

Raw or half-boiled eggs

Raw and undercooked animal foods contain a variety of food-borne bacteria and viruses. Changes in your metabolism and circulation during pregnancy may increase the risk of bacterial food poisoning, and your reaction may be more severe than if you were not pregnant.

Avoid:
Swordfish,

Shark,

Tilefish,

King mackerel

Limit:
Canned albacore tuna

Herbal Supplements
Herbal products have not been studied enough to be recommended during pregnancy. Do consult your doctor if you are planning to take these herbs.

Chinese medicine of unknown origin should not be consumed without approval from a qualified TCM practitioner for medicinal use and usage.

Alcohol
Mothers who drink alcohol have a higher risk of miscarriages and stillbirth, and excessive alcohol consumption may result in fetal alcohol syndrome, including facial deformities, low birth weight and mental retardation.

Unwashed Salad and Raw Vegetables Sprouts, including Alfalfa, Clover, Radish, and Mung Beans

Unwashed salads may be contaminated with bacteria from the soil, while raw vegetable sprouts contain high levels of germs, which can be harmful to health.

Reference: HealthHub