Can I take an alergy medicine with a decongestant such as zytec d while in myfirst trimester of pregnancy?

It depends. Medications are generally discouraged during the first trimester as there is a lack of human studies. Zyrtec (cetirizine) is a class b drug in pregnancy which means that there are some animal studies that demonstrate safety but no human studies. Pseudoephedrine is a class c drug which means that safety has not been demonstrated in animals nor humans. So the answer is it depends on your risk tolerance and sx.
Yes. We have no evidence that zyrtec (cetirizine) or Pseudoephedrine causes any harm in pregnancy so i counsel my patients that it is generally felt to be safe.
Yep. There is no evidence of birth defects with these meds. It's not good to have your head impacted w/ congestion. Be careful but over the counter meds r generally safe( nsaids after 32 weeks are cat d, like aleve, (naproxen) motrin) lest the companies that sold them would be out of business if birth defects or miscarriages were occurring. As advised be judicous but it's not healthy to have uncontrolled aller.