Ok found this on ehow:
How to Avoid Harmful Herbs During Pregnancy
1 Examine the ingredients of herbal teas. Many herbal teas, even those marketed as safe during pregnancy, contain natural ingredients that can cause uterine contractions and miscarriage if consumed in large quantities. Due to the brewing process, potentially harmful chemicals in herbs are more heavily concentrated in teas than in other food products.
2 Remember, the FDA does not regulate most herbs, so product quality varies significantly. Typically, the best herbs are the most expensive, but this is not always the case. If you have a midwife or natural health care provider, she may have a reliable source for herbal products and may sell them through her practice.
3 Avoid uterine-stimulating herbs, which can cause miscarriage, premature labor or birth defects. These herbs include, but are not limited to, the following: anise seed and oil, barberry, black cohosh, golden seal, juniper, marjoram, motherwort, passion flower, pennyroyal, peppermint oil and St. John's wort. Some herbs that stimulate the uterus, such as red raspberry leaf, can aid in delivery and are sometimes safe for use late in the third trimester. Consult a health care provider before use at any time during pregnancy.
4 Use the following culinary herbs and spices in moderation: caraway, chili, cinnamon, cumin, fennel, lavender, nutmeg, oregano, parsley, peppermint oil, rosemary, sage and thyme oil. Large quantities may lead to miscarriage or premature labor contractions, and have other harmful effects, so don't go overboard when seasoning food during pregnancy.
5 Stay away from herbs that can cause serious injury to mother and baby. Aloe vera, comfrey, false unicorn root, Peruvian bark and wormwood are among those herbs linked to birth defects such as coma and blindness. Pregnant women should avoid these herbs throughout pregnancy, even in small quantities.
6 Follow herb dosage guidelines, as indicated on product packaging. Overuse of an otherwise safe herb can cause health problems, especially during pregnancy when the digestive system slows down. Err on the side of caution, taking the lowest effective dose.
I am fed up now cos I use LOADS of herbs in cooking!!
