Swetha,   When you are pregnant, it's always best to talk with your obstetrician before beginning any new medication, as he/she knows you, your condition, and the condition of your fetus better than anyone.   As with most medicines, it is not known for sure if Zyrtec is safe for pregnant women to take, because no one wants to do research that could be harmful on pregnant women.  But many asthma and allergy medicines ARE used safely during pregnancy.   Your doctor can help you weigh any possible risks against the benefits of allergy control, so talk with your doctor, OK?   To your health, Kathi