Hista 3G Tablet contains Montelukast and Fexofenadine, which are used to relieve allergy-related symptoms such as sneezing, a runny nose, and cough. In pregnancy, especially in the first 12 weeks, medicines should be used only when clearly needed and prescribed by a doctor. Fexofenadine is an antihistamine, and available evidence suggests it is unlikely to cause harm to the baby when used as advised. Montelukast is also used in some pregnant women when needed, and current data does not show a clear risk of birth defects, but long-term studies are limited. Because of this, doctors prescribe it only when the expected benefit outweighs any potential risks. Since your doctor has recommended it, it is generally considered acceptable to take it as prescribed. If your symptoms worsen or you develop a fever, breathlessness, or a persistent cough, please seek medical attention promptly.