It is possible that the high level of iron in prenatal supplements can make your nausea worse. If this is the case for you, instead of stopping your prenatal multivitamin, try to avoid taking it on an empty stomach. Another strategy is to take it before bed. If you find you are unable to tolerate your supplement, you can ask your health care provider about prenatal supplements that have lower levels of iron which will be less likely to trigger nausea. Another option is to take folic acid supplement containing 0.4-1.0mg of folate by itself daily, until you are feeling better and ready to restart your prenatal supplement.