Excess saliva at any stage of pregnancy is common and is not harmful to you or your baby in any way - it's just very annoying.

What is the reason of this?

Excessive salivation can occur at any point in pregnancy and for a variety of reasons. Fluctuating and rising hormone levels are thought to affect excess saliva in early pregnancy, but morning sickness is likely the more likely cause, as nausea causes saliva to form, making it difficult to swallow. Later in pregnancy, heartburn can trigger excess saliva as your body's mechanism to neutralize acid in your esophagus.

Tips

Managing the increased amount of saliva basically boils down to managing heartburn and nausea as these are the main causes of excess saliva. Drinking plenty of water, eating smaller meals, and sucking on hard candies can help your body recycle extra saliva.