It is not recommended to treat diseases with random medications during pregnancy. Anti-allergy medications are antihistamines, which can easily cause drowsiness after taking them. If the medication is taken during the first three months of pregnancy, it may lead to an increase in the rate of fetal malformations and may affect the development of the fetal nervous system. If the medication is taken within 18 days of the formation of the fertilized egg, it will not have a great impact on the fetus. When taking anti-allergy medication, it is important to observe the week of pregnancy when the medication is taken, as well as the dosage of the medication and the type of medication being taken. If you take anti-allergy medication during pregnancy, you need to pay attention to the development of the fetus, and you need to do Down’s syndrome screening and 4D examination. If no abnormality is found in the fetus at the later stage of examination, there is usually no major effect.