The phrase "uterine stimulant" refers to something that can help the uterus, which is a part of a woman's reproductive system, to contract or become more active. Full definition
Many of the herbs used to increase milk supply (fenugreek and blessed thistle, for example) are also uterine stimulants; they may have strong enough actions to cause a miscarriage.» (breastfeedingtoday-llli.org)
Cinnamon is a fantastic anti-nauseant, antispasmodic, carminative (anti-gas), uterine anti-hemorrhagic (slows heavy flow) and warming uterine stimulant. (thehormonediva.com)
Since blessed thistle is a uterine stimulant that can cause contractions, using this herb during pregnancy could potentially lead to a pregnancy loss or premature labor. (verywellfamily.com)