Nasal Decongestants May Cause Birth Defect. Women who take nasal decongestants in the first trimester of their pregnancy may be raising the risk that their newborn will suffer from one or more rare birth defects, according to a new study. Researchers at the Slone Epidemiology Center at Boston University found that phenylephrine, … [Read more...] about Nasal Decongestants Taken in First Trimester can Lead to Birth Defect