Pregnancy has been known to affect the ears in different ways, including loss of hearing, the feeling of ear blockage, tinnitus and even vertigo. These are relatively common, and you may even notice headaches too. The reasons for these changes in your ears include hormones, increased blood flow, high blood pressure, iron deficiency and in some rare cases bone growth. Additionally, pregnancy can sometimes cause swelling in the sinuses, which includes the ears. If you’re noticing a significant change in your hearing, it’s important to tell your provider, but rest assured that it’s likely just another common side effect of pregnancy.