Hi peppper100,
Some herbs and spices can act as uterine stimulants and as such can potentially trigger uterine contractions. Mainly the 'hard' herbs, rosemary, thyme, turmeric (spice). The amounts required to cause this effect however would be the quantities found in herbal extracts /tinctures etc. the amounts we use in food is generally negligible and not something to worry about. also need to avoid essential oils of these herbs. Speak to a naturopath if you are overly concerned. HTH.