Omeprazole is usually contraindicated or avoided during pregnancy and should also be used with caution in nursing women. However, some literature shows that it is effective in the treatment of pregnancy sickness, so it can be used under the guidance of a medical professional, if necessary, after weighing the pros and cons. Omeprazole is indicated for the treatment of gastric ulcer and duodenal ulcer, and is classified as Category C in the safety classification of drugs used during pregnancy (it is clear in animal experiments that it has side effects on the fetus, but there is a lack of valid evidence in pregnant women, and it should be used only after it is clear that the benefits to the pregnant woman outweigh the harms to the fetus). Because omeprazole can pass through the placenta, its drug insert also clearly states that it is contraindicated in pregnant women and should be used with caution in nursing mothers. Most women experience vomiting in early pregnancy, mostly due to elevated HCG levels, altered thyroid function, and excessive mental stress. There is literature showing the efficacy of omeprazole and metoclopramide in treating severe vomiting in early pregnant women, and there is no clear literature showing that the use of this drug during pregnancy can have teratogenic and other related adverse consequences. Treatment options need to be selected at the doctor’s discretion. In general, when pregnant women experience digestive discomfort, it is better to avoid the use of drugs that are prohibited for pregnant women on the instructions, such as omeprazole, and give priority to non-pharmacological treatment, such as treatment by eating less and more meals, vitamin B supplementation, and psychotherapy. If the above treatment is not effective, the doctor needs to combine with clinical, discretionary choice of drugs such as omeprazole treatment.